Impact of Risk-Based therapy on late morbidity and mortality in neuroblastoma survivors: a report from the childhood cancer survivor study

BACKGROUND

Early efforts at risk-adapted therapy for neuroblastoma are predicted to result in differential late effects; the magnitude of these differences have not been well-described.

METHODS

Late mortality, subsequent malignant neoplasms (SMN), and severe/life-threatening chronic health conditions (CHCs), graded according to CTCAE v4.03, were assessed among 5-year CCSS survivors of neuroblastoma diagnosed 1987-1999. Using age, stage at diagnosis, and treatment, survivors were classified into risk groups (low [n = 425]; intermediate [n = 252]; high [n = 245]). Standardized mortality ratios (SMR) and standardized incidence ratios (SIR) of SMNs were compared to matched population controls. Cox regression models estimated hazard ratios (HR) and 95% confidence intervals (CI) for CHC compared to 1,029 CCSS siblings.

RESULTS

Among survivors (49.8% male; median age 21 years, range 7-42; median follow-up 19.3 years, range 5-29.9), 80% with low-risk disease were treated with surgery alone, while 79.1% with high-risk disease received surgery, radiation, chemotherapy ± autologous stem cell transplant (ASCT). All-cause mortality was elevated across risk groups (SMRhigh=27.7 [21.4-35.8]; SMRintermediate=3.3 [1.7-6.5]; SMRlow=2.8 [1.7-4.8]). SMN risk was increased among high- and intermediate-risk survivors (SIRhigh=28.0 [18.5-42.3]; SIRintermediate=3.7 [1.2-11.3]), but did not differ from the US population for survivors of low-risk disease. Compared to siblings, survivors had an increased risk of grade 3-5 CHCs, particularly among those with high-risk disease (HRhigh=16.1 [11.2-23.2]; HRintermediate=6.3 [3.8-10.5]; HRlow=1.8 [1.1-3.1]).

CONCLUSION

Survivors of high-risk disease treated in the early days of risk stratification carry a markedly elevated burden of late recurrence, SMN, and organ-related multi-morbidity, while survivors of low/intermediate-risk disease have a modest risk of late adverse outcomes.

Trends in Radiation Dose to the Contralateral Breast During Breast Cancer Radiation Therapy

Over 4 million survivors of breast cancer live in the United States, 35% of whom were treated before 2009. Approximately half of patients with breast cancer receive radiation therapy, which exposes the untreated contralateral breast to radiation and increases the risk of a subsequent contralateral breast cancer (CBC). Radiation oncology has strived to reduce unwanted radiation dose, but it is unknown whether a corresponding decline in actual dose received to the untreated contralateral breast has occurred. The purpose of this study was to evaluate trends in unwanted contralateral breast radiation dose to inform risk assessment of second primary cancer in the contralateral breast for long-term survivors of breast cancer. Individually estimated radiation absorbed doses to the four quadrants and areola central area of the contralateral breast were estimated for 2,132 women treated with radiation therapy for local/regional breast cancers at age <55 years diagnosed between 1985 and 2008. The two inner quadrant doses and two outer quadrant doses were averaged. Trends in dose to each of the three areas of the contralateral breast were evaluated in multivariable models. The population impact of reducing contralateral breast dose on the incidence of radiation-associated CBC was assessed by estimating population attributable risk fraction (PAR) in a multivariable model. The median dose to the inner quadrants of the contralateral breast was 1.70 Gy; to the areola, 1.20 Gy; and to the outer quadrants, 0.72 Gy. Ninety-two percent of patients received ≥1 Gy to the inner quadrants. For each calendar year of diagnosis, dose declined significantly for each location, most rapidly for the inner quadrants (0.04 Gy/year). Declines in dose were similar across subgroups defined by age at diagnosis and body mass index. The PAR for CBC due to radiation exposure >1 Gy for women <40 years of age was 17%. Radiation dose-reduction measures have reduced dose to the contralateral breast during breast radiation therapy. Reducing the dose to the contralateral breast to <1 Gy could prevent an estimated 17% of subsequent radiation-associated CBCs for women treated under 40 years of age. These dose estimates inform CBC surveillance for the growing number of breast cancer survivors who received radiation therapy as young women in recent decades. Continued reductions in dose to the contralateral breast could further reduce the incidence of radiation-associated CBC.

Cardiac Substructure Radiation Dose and Risk of Late Cardiac Disease in Survivors of Childhood Cancer: A Report From the Childhood Cancer Survivor Study

PURPOSE

Radiation-associated cardiac disease is a major cause of morbidity/mortality among childhood cancer survivors. Radiation dose-response relationships for cardiac substructures and cardiac diseases remain unestablished.

METHODS

Using the 25,481 5-year survivors of childhood cancer treated from 1970 to 1999 in the Childhood Cancer Survivor Study, we evaluated coronary artery disease (CAD), heart failure (HF), valvular disease (VD), and arrhythmia. We reconstructed radiation doses for each survivor to the coronary arteries, chambers, valves, and whole heart. Excess relative rate (ERR) models and piecewise exponential models evaluated dose-response relationships.

RESULTS

The cumulative incidence 35 years from diagnosis was 3.9% (95% CI, 3.4 to 4.3) for CAD, 3.8% (95% CI, 3.4 to 4.2) for HF, 1.2% (95% CI, 1.0 to 1.5) for VD, and 1.4% (95% CI, 1.1 to 1.6) for arrhythmia. A total of 12,288 survivors (48.2%) were exposed to radiotherapy. Quadratic ERR models improved fit compared with linear ERR models for the dose-response relationship between mean whole heart and CAD, HF, and arrhythmia, suggesting a potential threshold dose; however, such departure from linearity was not observed for most cardiac substructure end point dose-response relationships. Mean doses of 5-9.9 Gy to the whole heart did not increase the risk of any cardiac diseases. Mean doses of 5-9.9 Gy to the right coronary artery (rate ratio [RR], 2.6 [95% CI, 1.6 to 4.1]) and left ventricle (RR, 2.2 [95% CI, 1.3 to 3.7]) increased risk of CAD, and to the tricuspid valve (RR, 5.5 [95% CI, 2.0 to 15.1]) and right ventricle (RR, 8.4 [95% CI, 3.7 to 19.0]) increased risk of VD.

CONCLUSION

Among children with cancer, there may be no threshold dose below which radiation to the cardiac substructures does not increase the risk of cardiac diseases. This emphasizes their importance in modern treatment planning.

Use of Intramuscular Ephedrine Sulfate During Kidney Transplantation

Hypotension during kidney transplantation can be common. Vasopressor use during these procedures is often avoided, with a fear of decreasing renal perfusion in the transplanted kidney. However, adequate perfusion for the rest of the body is also necessary, and given that these patients often have underlying hypertension or other comorbid conditions, an appropriate mean arterial pressure (MAP) has to be maintained. Intramuscular injections of ephedrine have been studied in the anesthesiology literature in a variety of case types, and it is seen as a safe and effective method to boost MAP. We present a case series of three patients who underwent renal transplantation and who received an intramuscular injection of ephedrine for hypotension control. The medication worked well for increasing blood pressures without apparent side effects. All three patients were followed for more than one year, and all patients had good graft function at the end of that time period. This series shows that while further research is necessary in this arena, intramuscular ephedrine may have a place in the management of persistent hypotension in the operating room during kidney transplantation.

Late Health Outcomes Among Survivors of Wilms Tumor Diagnosed Over Three Decades: A Report From the Childhood Cancer Survivor Study

PURPOSE

To evaluate long-term morbidity and mortality among unilateral, nonsyndromic Wilms tumor (WT) survivors according to conventional treatment regimens.

METHODS

Cumulative incidence of late mortality (≥ 5 years from diagnosis) and chronic health conditions (CHCs) were evaluated in WT survivors from the Childhood Cancer Survivor Study. Outcomes were evaluated by treatment, including nephrectomy combined with vincristine and actinomycin D (VA), VA + doxorubicin + abdominal radiotherapy (VAD + ART), VAD + ART + whole lung radiotherapy, or receipt of ≥ 4 chemotherapy agents.

RESULTS

Among 2,008 unilateral WT survivors, 142 deaths occurred (standardized mortality ratio, 2.9, 95% CI, 2.5 to 3.5; 35-year cumulative incidence of death, 7.8%, 95% CI, 6.3 to 9.2). The 35-year cumulative incidence of any grade 3-5 CHC was 34.1% (95% CI, 30.7 to 37.5; rate ratio [RR] compared with siblings 3.0, 95% CI, 2.6 to 3.5). Survivors treated with VA alone had comparable risk for all-cause late mortality relative to the general population (standardized mortality ratio, 1.0; 95% CI, 0.5 to 1.7) and modestly increased risk for grade 3-5 CHCs compared with siblings (RR, 1.5; 95% CI, 1.1 to 2.0), but remained at increased risk for intestinal obstruction (RR, 9.4; 95% CI, 3.9 to 22.2) and kidney failure (RR, 11.9; 95% CI, 4.2 to 33.6). Magnitudes of risk for grade 3-5 CHCs, including intestinal obstruction, kidney failure, premature ovarian insufficiency, and heart failure, increased by treatment group intensity.

CONCLUSION

With approximately 40% of patients with newly diagnosed WT currently treated with VA alone, the burden of late mortality/morbidity in future decades is projected to be lower than that for survivors from earlier eras. Nevertheless, the risk of late effects such as intestinal obstruction and kidney failure was elevated across all treatment groups, and there was a dose-dependent increase in risk for all grade 3-5 CHCs by treatment group intensity.

Long-Term Morbidity and Mortality Among Survivors of Neuroblastoma Diagnosed During Infancy: A Report From the Childhood Cancer Survivor Study

PURPOSE

To describe the risk of late mortality, subsequent malignant neoplasms (SMNs), and chronic health conditions (CHCs) in survivors of neuroblastoma diagnosed in infancy by treatment era and exposures.

METHODS

Among 5-year survivors of neuroblastoma in the Childhood Cancer Survivor Study diagnosed age < 1 year between 1970 and 1999, we examined the cumulative incidence of late (> 5 years from diagnosis) mortality, SMN, and CHCs (grades 2-5 and 3-5). Multivariable Cox regression models estimated hazard ratios (HRs) and 95% CIs by decade and treatment (surgery-alone v chemotherapy with or without surgery [C ± S] v radiation with or without chemotherapy ± surgery [R ± C ± S]) among survivors and between survivors and 5,051 siblings.

RESULTS

Among 1,397 eligible survivors, the 25-year cumulative incidence of late mortality was 2.1% (95% CI, 1.3 to 3.9) with no difference by treatment era. Among 990 participants who completed a baseline survey, fewer survivors received radiation in more recent eras (51.2% 1970s, 20.4% 1980s, and 10.1% 1990s; P < .001). Risk of SMN was elevated only among individuals treated with radiation-containing regimens compared with surgery alone (HR[C ± S], 3.2 [95% CI, 0.9 to 11.6]; HR[R ± C ± S], 5.7 [95% CI, 1.2 to 28.1]). In adjusted models, there was a 50% reduction in risk of grade 3-5 CHCs in the 1990s versus 1970s (HR, 0.5 [95% CI, 0.3 to 0.9]; P = .01); individuals treated with radiation had a 3.6-fold risk for grade 3-5 CHCs (95% CI, 2.1 to 6.2) versus those treated with surgery alone. When compared with siblings, risk of grade 3-5 CHCs for survivors was lowest in the most recent era (HR[1970s], 4.7 [95% CI, 3.4 to 6.5]; HR[1980s], 4.6 [95% CI, 3.3 to 6.4]; HR[1990s], 2.5 [95% CI, 1.7 to 3.9]).

CONCLUSION

Neuroblastoma survivors treated during infancy have a relatively low absolute burden of late mortality and SMN. Encouragingly, risk of CHCs has declined in more recent eras with reduced exposure to radiation therapy.

Health Benefits and Cost-Effectiveness of Children's Oncology Group Breast Cancer Screening Guidelines for Chest-Irradiated Hodgkin Lymphoma Survivors

PURPOSE

To evaluate the outcomes and cost-effectiveness of the Children's Oncology Group Guideline recommendation for breast cancer (BC) screening using mammography (MAM) and breast magnetic resonance imaging (MRI) in female chest-irradiated childhood Hodgkin lymphoma (HL) survivors. Digital breast tomosynthesis (DBT), increasingly replacing MAM in practice, was also examined.

METHODS

Life years (LYs), quality-adjusted LYs (QALYs), BC mortality, health care costs, and false-positive screen frequencies of undergoing annual MAM, DBT, MRI, MAM + MRI, and DBT + MRI from age 25 to 74 years were estimated by microsimulation. BC risks and non-BC mortality were estimated from female 5-year survivors of HL in the Childhood Cancer Survivor Study and the US population. Test performance of MAM and MRI was synthesized from HL studies, and that of DBT from the general population. Costs (2017 US dollars [USD]) and utility weights were obtained from the medical literature. Incremental cost-effectiveness ratios (ICERs) were calculated.

RESULTS

With 100% screening adherence, annual BC screening extended LYs by 0.34-0.46 years over no screening. If the willingness-to-pay threshold to gain a quality-adjusted LY was ICER < $100,000 USD, annual MAM at age 25-74 years was the only cost-effective strategy. When nonadherence was taken into consideration, only annual MAM at age 30-74 years (ICER = $56,972 USD) was cost-effective. Supplementing annual MAM with MRI costing $545 USD was not cost-effective under either adherence condition. If MRI costs were reduced to $300 USD, adding MRI to annual MAM at age 30-74 years could become more cost-effective, particularly in the reduced adherence condition (ICER = $133,682 USD).

CONCLUSION

Annual BC screening using MAM at age 30-74 years is effective and cost-effective in female chest-irradiated HL survivors. Although annual adjunct MRI is not cost-effective at $545 USD cost, it could become cost-effective as MRI cost is reduced, a plausible scenario with the emergent use of abbreviated MRI.

Development and validation of a population-based anatomical colorectal model for radiation dosimetry in late effects studies of survivors of childhood cancer

PURPOSE

The purposes of this study were to develop and integrate a colorectal model that incorporates anatomical variations of pediatric patients into the age-scalable MD Anderson Late Effects (MDA-LE) computational phantom, and validate the model for pediatric radiation therapy (RT) dose reconstructions.

METHODS

Colorectal contours were manually derived from whole-body non-contrast computed tomography (CT) scans of 114 pediatric patients (age range: 2.1-21.6 years, 74 males, 40 females). One contour was used for an anatomical template, 103 for training and 10 for testing. Training contours were used to create a colorectal principal component analysis (PCA)-based statistical shape model (SSM) to extract the population's dominant deformations. The SSM was integrated into the MDA-LE phantom. Geometric accuracy was assessed between patient-specific and SSM contours using several overlap metrics. Two alternative colorectal shapes were generated using the first 17 dominant modes of the PCA-based SSM. Dosimetric accuracy was assessed by comparing colorectal doses from test patients' CT-based RT plans (ground truth) with reconstructed doses for the mean and two alternative models in age-matched MDA-LE phantoms.

RESULTS

When using all 103 PCA modes, the mean (min-max) Dice similarity coefficient, distance-to-agreement and Hausdorff distance between the patient-specific and reconstructed contours for the test patients were 0.89 (0.85-0.91), 2.1 mm (1.7-3.0), and 8.6 mm (5.7-14.3), respectively. The average percent difference between reconstructed and ground truth mean and maximum colorectal doses for the mean (alternative 1, 2) model were 6.3% (8.1%, 6.1%) and 4.4% (4.3%, 4.7%), respectively.

CONCLUSIONS

We developed, validated and integrated a colorectal PCA-based SSM into the MDA-LE phantom and demonstrated its dosimetric performance for accurate pediatric RT dose reconstruction.

Association of Changes in Cancer Therapy Over 3 Decades With Risk of Subsequent Breast Cancer Among Female Childhood Cancer Survivors: A Report From the Childhood Cancer Survivor Study (CCSS)

Importance

Breast cancer is the most common invasive subsequent malignant disease in childhood cancer survivors, though limited data exist on changes in breast cancer rates as primary cancer treatments have evolved.

Objective

To quantify the association between temporal changes in cancer treatment over 3 decades and subsequent breast cancer risk.

Design, Setting, and Participants

Retrospective cohort study of 5-year cancer survivors diagnosed when younger than 21 years between 1970 and 1999, with follow-up through December 5, 2020.

Exposures

Radiation and chemotherapy dose changes over time.

Main Outcomes and Measures

Breast cancer cumulative incidence rates and age-specific standardized incidence ratios (SIRs) compared across treatment decades (1970-1999). Piecewise exponential models estimated invasive breast cancer and ductal carcinoma in situ (DCIS) risk and associations with treatment exposures, adjusted for age at childhood cancer diagnosis and attained age.

Results

Among 11 550 female survivors (median age, 34.2 years; range 5.6-66.8 years), 489 developed 583 breast cancers: 427 invasive, 156 DCIS. Cumulative incidence was 8.1% (95% CI, 7.3%-9.0%) by age 45 years. An increased breast cancer risk (SIR, 6.6; 95% CI, 6.1-7.2) was observed for survivors compared with the age-sex-calendar-year-matched general population. Changes in therapy by decade included reduced rates of chest (34% in the 1970s, 22% in the 1980s, and 17% in the 1990s) and pelvic radiotherapy (26%, 17%, and 13% respectively) and increased rates of anthracycline chemotherapy exposures (30%, 51%, and 64%, respectively). Adjusting for age and age at diagnosis, the invasive breast cancer rate decreased 18% every 5 years of primary cancer diagnosis era (rate ratio [RR], 0.82; 95% CI, 0.74-0.90). When accounting for chest radiotherapy exposure, the decline attenuated to an 11% decrease every 5 years (RR, 0.89; 95% CI, 0.81-0.99). When additionally adjusted for anthracycline dose and pelvic radiotherapy, the decline every 5 years increased to 14% (RR, 0.86; 95% CI, 0.77-0.96). Although SIRs of DCIS generally increased over time, there were no statistically significant changes in incidence.

Conclusions and Relevance

Invasive breast cancer rates in childhood cancer survivors have declined with time, especially in those younger than 40 years. This appears largely associated with the reduced use of chest radiation therapy, but was tempered by concurrent changes in other therapies.

Genome architecture used to supplement species delineation in two cryptic marine ciliates

The purpose of this study is to determine which taxonomic methods can elucidate clear and quantifiable differences between two cryptic ciliate species, and to test the utility of genome architecture as a new diagnostic character in the discrimination of otherwise indistinguishable taxa. Two cryptic tintinnid ciliates, Schmidingerella arcuata and Schmidingerella meunieri, are compared via traditional taxonomic characters including lorica morphometrics, ribosomal RNA (rRNA) gene barcodes and ecophysiological traits. In addition, single-cell 'omics analyses (single-cell transcriptomics and genomics) are used to elucidate and compare patterns of micronuclear genome architecture between the congeners. The results include a highly similar lorica that is larger in S. meunieri, a 0%-0.5% difference in rRNA gene barcodes, two different and nine indistinguishable growth responses among 11 prey treatments, and distinct patterns of micronuclear genomic architecture for genes detected in both ciliates. Together, these results indicate that while minor differences exist between S. arcuata and S. meunieri in common indices of taxonomic identification (i.e., lorica morphology, DNA barcode sequences and ecophysiology), differences exist in their genomic architecture, which suggests potential genetic incompatibility. Different patterns of micronuclear architecture in genes shared by both isolates also enable the design of species-specific primers, which are used in this study as unique "architectural barcodes" to demonstrate the co-occurrence of both ciliates in samples collected from a NW Atlantic estuary. These results support the utility of genomic architecture as a tool in species delineation, especially in ciliates that are cryptic or otherwise difficult to differentiate using traditional methods of identification.

Minimally Invasive Esophagectomy Is Associated with Superior Survival Compared to Open Surgery

INTRODUCTION

Minimally invasive esophagectomy (MIE) has not been associated with a long-term survival advantage compared to open esophagectomy (OE). We investigated survival differences between MIE, including laparoscopic and robotic, and OE.

METHODS

Patients undergoing esophagectomy from 2010 to 2014 with T_1-4N_0-3M₀, adenocarcinoma or squamous cell histology, in middle or lower esophagus were queried from the National Cancer Database and stratified into groups based on their surgical procedure: robotic, laparoscopic, or OE. Propensity matching (1:1) was done between robotic and laparoscopic to produce an MIE group. The MIE group was matched to OE yielding a 1:1:2 matching of robotic:laparoscopic:OE. Postoperative outcomes and survival (Kaplan-Meier) were compared between groups.

RESULTS

Prior to matching, 7,163 patients met inclusion criteria and a greater portion underwent OE (67.7%) than MIE (laparoscopic 24.9% and robotic 7.4%). Matching yielded similar groups (robotic = 527, laparoscopic = 527, and OE =1054). Compared to OE, MIE patients had a significantly greater number of nodes sampled and trended toward increased R0 resections (96.1% vs 94.3%, P = .053). OE was associated with a longer median postoperative stay (10 vs 9 days, P = .001). Mortality at 30 and 90 days was similar. However, postoperative survival for MIE was significantly greater than OE (P < .001). No survival difference existed between robotic and laparoscopic (P = .723).

CONCLUSIONS

MIE is associated with increased number of nodes examined and a shorter postoperative length of stay. After propensity matching, patients undergoing MIE had better long but not short-term survival than OE. This benefit seems to be independent of the use of robotic technology.

Body region-specific 3D age-scaling functions for scaling whole-body computed tomography anatomy for pediatric late effects studies

Purpose.Radiation epidemiology studies of childhood cancer survivors treated in the pre-computed tomography (CT) era reconstruct the patients' treatment fields on computational phantoms. For such studies, the phantoms are commonly scaled to age at the time of radiotherapy treatment because age is the generally available anthropometric parameter. Several reference size phantoms are used in such studies, but reference size phantoms are only available at discrete ages (e.g.: newborn, 1, 5, 10, 15, and Adult). When such phantoms are used for RT dose reconstructions, the nearest discrete-aged phantom is selected to represent a survivor of a specific age. In this work, we (1) conducted a feasibility study to scale reference size phantoms at discrete ages to various other ages, and (2) evaluated the dosimetric impact of using exact age-scaled phantoms as opposed to nearest age-matched phantoms at discrete ages.Methods.We have adopted the University of Florida/National Cancer Institute (UF/NCI) computational phantom library for our studies. For the feasibility study, eight male and female reference size UF/NCI phantoms (5, 10, 15, and 35 years) were downscaled to fourteen different ages which included next nearest available lower discrete ages (1, 5, 10 and 15 years) and the median ages at the time of RT for Wilms' tumor (3.9 years), craniospinal (8.0 years), and all survivors (9.1 years old) in the Childhood Cancer Survivor Study (CCSS) expansion cohort treated with RT. The downscaling was performed using our in-house age scaling functions (ASFs). To geometrically validate the scaling, Dice similarity coefficient (DSC), mean distance to agreement (MDA), and Euclidean distance (ED) were calculated between the scaled and ground-truth discrete-aged phantom (unscaled UF/NCI) for whole-body, brain, heart, liver, pancreas, and kidneys. Additionally, heights of the scaled phantoms were compared with ground-truth phantoms' height, and the Centers for Disease Control and Prevention (CDC) reported 50th percentile height. Scaled organ masses were compared with ground-truth organ masses. For the dosimetric assessment, one reference size phantom and seventeen body-size dependent 5-year-old phantoms (9 male and 8 female) of varying body mass indices (BMI) were downscaled to 3.9-year-old dimensions for two different radiation dose studies. For the first study, we simulated a 6 MV photon right-sided flank field RT plan on a reference size 5-year-old and 3.9-year-old (both of healthy BMI), keeping the field size the same in both cases. Percent of volume receiving dose ≥15 Gy (V₁₅) and the mean dose were calculated for the pancreas, liver, and stomach. For the second study, the same treatment plan, but with patient anatomy-dependent field sizes, was simulated on seventeen body-size dependent 5- and 3.9-year-old phantoms with varying BMIs. V₁₅, mean dose, and minimum dose received by 1% of the volume (D₁), and by 95% of the volume (D₉₅) were calculated for pancreas, liver, stomach, left kidney (contralateral), right kidney, right and left colons, gallbladder, thoracic vertebrae, and lumbar vertebrae. A non-parametric Wilcoxon rank-sum test was performed to determine if the dose to organs of exact age-scaled and nearest age-matched phantoms were significantly different (p < 0.05).Results.In the feasibility study, the best DSCs were obtained for the brain (median: 0.86) and whole-body (median: 0.91) while kidneys (median: 0.58) and pancreas (median: 0.32) showed poorer agreement. In the case of MDA and ED, whole-body, brain, and kidneys showed tighter distribution and lower median values as compared to other organs. For height comparison, the overall agreement was within 2.8% (3.9 cm) and 3.0% (3.2 cm) of ground-truth UF/NCI and CDC reported 50th percentile heights, respectively. For mass comparison, the maximum percent and absolute differences between the scaled and ground-truth organ masses were within 31.3% (29.8 g) and 211.8 g (16.4%), respectively (across all ages). In the first dosimetric study, absolute difference up to 6% and 1.3 Gy was found for V₁₅and mean dose, respectively. In the second dosimetric study, V₁₅and mean dose were significantly different (p < 0.05) for all studied organs except the fully in-beam organs. D₁and D₉₅were not significantly different for most organs (p > 0.05).Conclusion.We have successfully evaluated our ASFs by scaling UF/NCI computational phantoms from one age to another age, which demonstrates the feasibility of scaling any CT-based anatomy. We have found that dose to organs of exact age-scaled and nearest aged-matched phantoms are significantly different (p < 0.05) which indicates that using the exact age-scaled phantoms for retrospective dosimetric studies is a better approach.

White matter tracts that overlap with the thalamus and the putamen are protected against multiple sclerosis pathology

BACKGROUND

The thalamus and the putamen are highly connected hubs implicated in multiple sclerosis (MS) pathology. It remains unclear if white matter (WM) tracts, which pass through them, have a different susceptibility to MS pathology, and if so, if their impact on disability predominates over that exerted by disease in other WM tracts. We hypothesized that WM tracts connected to and passing through these hubs (subsequently termed hub+ tracts) would be more susceptible to MS-related pathology than tracts that do not pass through them (hub- tracts) due to retrograde and anterograde distant degeneration. Thus, we compared the lesion load and neurite orientation dispersion and density imaging (NODDI) derived metrics between hub+ and hub- tracts and assessed the relationship between these MRI metrics and those of physical impairment.

METHODS

Eighteen patients (mean age of 45.5 years, 12 females) had 3 Tesla MRI consisting of T1-weighted and T2-weighted Fluid Attenuated Inversion Recovery (FLAIR), and NODDI from which the orientation dispersion index (ODI), neurite density index (NDI), and isotropic volume fraction (IVF) were derived. Forty-nine WM tracts, i.e., 12 hub+ and 37 hub- tracts, were segmented out. Exploratory analyses of the differences in lesion burden, whole tract and normal appearing WM (NAWM) NODDI metrics were carried out between the two types of tracts using a Mann-Whitney U test. Correlations with physical impairment, quantified using the expanded disability status scale (EDSS) and timed 25-foot walk (T25FW) test were assessed using Spearman correlation analyses.

RESULTS

Hub- tracts had larger T1- (p<0.001) and T2-lesion (p<0.001) volumes; lower ODI (p<0.001), NDI (p<0.001) and higher IVF (p = 0.020) in comparison to hub+ tracts. Measures of tissue injury in hub+ tracts correlated with those of clinical disability, though less strongly than in hub- tracts.

CONCLUSIONS

Contrary to our hypothesis, our exploratory pilot study results suggest that WM tracts that overlap with the thalamus and the putamen have a lower degree of lesional and non-lesional tissue injury, suggesting a protective role of the hubs against MS pathology or a higher degree of vulnerability of those not passing through hub stations. We also show a weaker association between disability impairment and hub+ pathology, compared to that in hub- tracts. Our findings point to a potential role of disease location in relation to hubs as guidance for treatment personalization in MS.

Lung Cancer as a Subsequent Malignant Neoplasm in Survivors of Childhood Cancer

BACKGROUND

Lung cancer, the most common cause of cancer-related death in adults, has not been well studied as a subsequent malignant neoplasm (SMN) in childhood cancer survivors. We assessed prevalence, risk factors, and outcomes for lung SMN in the Childhood Cancer Survivor Study (CCSS) cohort.

METHODS

Among 25,654 5-year survivors diagnosed with childhood cancer (<21 years), lung cancer was self-reported and confirmed by pathology record review. Standardized incidence ratios (SIR) and cumulative incidences were calculated, comparing survivors to the general population, and hazard ratios (HR) were estimated using Cox regression for diagnosis and treatment exposures.

RESULTS

Forty-two survivors developed a lung SMN [SIR, 4.0; 95% confidence interval (CI), 2.9-5.4] with a cumulative incidence of 0.16% at 30 years from diagnosis (95% CI, 0.09%-0.23%). In a treatment model, chest radiation doses of 10-30 Gy (HR, 3.4; 95% CI, 1.05-11.0), >30-40 Gy (HR, 4.6; 95% CI, 1.5-14.3), and >40 Gy (HR, 9.1; 95% CI, 3.1-27.0) were associated with lung SMN, with a monotone dose trend (P trend < 0.001). Survivors of Hodgkin lymphoma (SIR, 9.3; 95% CI, 6.2-13.4) and bone cancer (SIR, 4.4; 95% CI, 1.8-9.1) were at greatest risk for lung SMN.

CONCLUSIONS

Survivors of childhood cancer are at increased risk for lung cancer compared with the general population. Greatest risk was observed among survivors who received chest radiotherapy or with primary diagnoses of Hodgkin lymphoma or bone cancer.

IMPACT

This study describes the largest number of observed lung cancers in childhood cancer survivors and elucidates need for further study in this aging and growing population.

Phase II study of ceralasertib (AZD6738) in combination with durvalumab in patients with advanced/metastatic melanoma who have failed prior anti-PD-1 therapy

BACKGROUND

Modulating the DNA damage response and repair (DDR) pathways is a promising strategy for boosting cancer immunotherapy. Ceralasertib (AZD6738) is an oral inhibitor of the serine/threonine protein kinase ataxia telangiectasia and Rad3-related protein, which is crucial for DDR.

PATIENTS AND METHODS

This phase II trial evaluated ceralasertib plus durvalumab for the treatment of patients with metastatic melanoma who had failed anti-programmed cell death protein 1 therapy.

RESULTS

Among the 30 patients, we observed an overall response rate of 31.0% and a disease control rate of 63.3%. Responses were evident across patients with acral, mucosal, and cutaneous melanoma. The median duration of response was 8.8 months (range, 3.8-11.7 months). The median progression-free survival was 7.1 months (95% confidence interval, 3.6-10.6 months), and the median overall survival was 14.2 months (95% confidence interval, 9.3-19.1 months). Common adverse events were largely hematologic and manageable with dose interruptions and reductions. Exploratory biomarker analysis suggested that tumors with an immune-enriched microenvironment or alterations in the DDR pathway were more likely to respond to the study treatment.

CONCLUSION

We conclude that ceralasertib in combination with durvalumab has promising antitumor activity among patients with metastatic melanoma who have failed anti-programmed cell death protein 1 therapy, and constitute a population with unmet needs.

Coronary Artery Disease in Young Women After Radiation Therapy for Breast Cancer: The WECARE Study

Background

Radiation therapy (RT) for breast cancer increases risk of coronary artery disease (CAD). Women treated for left- vs right-sided breast cancer receive greater heart radiation exposure, which may further increase this risk. The risk of radiation-associated CAD specifically among younger breast cancer survivors is not well defined.

Objectives

The purpose of this study was to report CAD risk among participants in the Women's Environmental Cancer and Radiation Epidemiology Study.

Methods

A total of 1,583 women who were <55 years of age when diagnosed with breast cancer between 1985 and 2008 completed a cardiovascular health questionnaire. Risk of radiation-associated CAD was evaluated by comparing women treated with left-sided RT with women treated with right-sided RT using multivariable Cox proportional hazards models. Effect modification by treatment and cardiovascular risk factors was examined.

Results

In total, 517 women who did not receive RT and 94 women who had a pre-existing cardiovascular disease diagnosis were excluded, leaving 972 women eligible for analysis. Their median follow-up time was 14 years (range 1-29 years). The 27.5-year cumulative incidences of CAD for women receiving left- vs right-sided RT were 10.5% and 5.8%, respectively (P = 0.010). The corresponding HR of CAD for left- vs right-sided RT in the multivariable Cox model was 2.5 (95% CI: 1.3-4.7). There was no statistically significant effect modification by any factor evaluated.

Conclusions

Young women treated with RT for left-sided breast cancer had over twice the risk of CAD compared with women treated with RT for right-sided breast cancer. Laterality of RT is independently associated with an increased risk of CAD and should be considered in survivorship care of younger breast cancer patients.

Late-onset kidney failure in survivors of childhood cancer: a report from the Childhood Cancer Survivor Study

BACKGROUND

The incidence of and risk factors for late-onset kidney failure among survivors over the very long term remains understudied.

MATERIALS AND METHODS

A total of 25,530 childhood cancer survivors (median follow-up 22.3 years, interquartile range 17.4-28.8) diagnosed between 1970 and 1999, and 5045 siblings from the Childhood Cancer Survivor Study were assessed for self-reported late-onset kidney failure, defined as dialysis, renal transplantation, or death attributable to kidney disease. Piecewise exponential models evaluated associations between risk factors and the rate of late-onset kidney failure.

RESULTS

A total of 206 survivors and 10 siblings developed late-onset kidney failure, a 35-year cumulative incidence of 1.7% (95% confidence interval [CI] = 1.4-1.9) and 0.2% (95% confidence interval [CI] = 0.1-0.4), respectively, corresponding to an adjusted rate ratio (RR) of 4.9 (95% CI = 2.6-9.2). High kidney dose from radiotherapy (≥15Gy; RR = 4.0, 95% CI = 2.1-7.4), exposure to high-dose anthracycline (≥250 mg/m2; RR = 1.6, 95% CI = 1.0-2.6) or any ifosfamide chemotherapy (RR = 2.6, 95% CI = 1.2-5.7), and nephrectomy (RR = 1.9, 95% CI = 1.0-3.4) were independently associated with elevated risk for late-onset kidney failure among survivors. Survivors who developed hypertension, particularly in the context of prior nephrectomy (RR = 14.4, 95% CI = 7.1-29.4 hypertension with prior nephrectomy; RR = 5.9, 95% CI = 3.3-10.5 hypertension without prior nephrectomy), or diabetes (RR = 2.2, 95%CI = 1.2-4.2) were also at elevated risk for late-onset kidney failure.

CONCLUSIONS

Survivors of childhood cancer are at increased risk for late-onset kidney failure. Kidney dose from radiotherapy ≥15 Gy, high-dose anthracycline, any ifosfamide, and nephrectomy were associated with increased risk of late-onset kidney failure among survivors. Successful diagnosis and management of modifiable risk factors such as diabetes and hypertension may mitigate the risk for late-onset kidney failure. The association of late-onset kidney failure with anthracycline chemotherapy represents a novel finding that warrants further study.

Radiation therapy related cardiac disease risk in childhood cancer survivors: Updated dosimetry analysis from the Childhood Cancer Survivor Study

BACKGROUND AND PURPOSE

We previously evaluated late cardiac disease in long-term survivors in the Childhood Cancer Survivor Study (CCSS) based on heart radiation therapy (RT) doses estimated from an age-scaled phantom with a simple atlas-based heart model (H_Atlas). We enhanced our phantom with a high-resolution CT-based anatomically realistic and validated age-scalable cardiac model (H_Hybrid). We aimed to evaluate how this update would impact our prior estimates of RT-related late cardiac disease risk in the CCSS cohort.

METHODS

We evaluated 24,214 survivors from the CCSS diagnosed from 1970 to 1999. RT fields were reconstructed on an age-scaled phantom with H_Hybrid and mean heart dose (D_m), percent volume receiving ≥ 20 Gy (V₂₀) and ≥ 5 Gy with V₂₀ = 0 ( [Formula: see text] ) were calculated. We reevaluated cumulative incidences and adjusted relative rates of grade 3-5 Common Terminology Criteria for Adverse Events outcomes for any cardiac disease, coronary artery disease (CAD), and heart failure (HF) in association with D_m, V₂₀, and [Formula: see text] (as categorical variables). Dose-response relationships were evaluated using piecewise-exponential models, adjusting for attained age, sex, cancer diagnosis age, race/ethnicity, time-dependent smoking history, diagnosis year, and chemotherapy exposure and doses. For relative rates, D_m was also considered as a continuous variable.

RESULTS

Consistent with previous findings with H_Atlas, reevaluation using H_Hybrid dosimetry found that, D_m ≥ 10 Gy, V₂₀ ≥ 0.1%, and [Formula: see text]  ≥ 50% were all associated with increased cumulative incidences and relative rates for any cardiac disease, CAD, and HF. While updated risk estimates were consistent with previous estimates overall without statistically significant changes, there were some important and significant (P < 0.05) increases in risk with updated dosimetry for D_m in the category of 20 to 29.9 Gy and V₂₀ in the category of 30% to 79.9%. When changes in the linear dose-response relationship for D_m were assessed, the slopes of the dose response were steeper (P < 0.001) with updated dosimetry. Changes were primarily observed among individuals with chest-directed RT with prescribed doses ≥ 20 Gy.

CONCLUSION

These findings present a methodological advancement in heart RT dosimetry with improved estimates of RT-related late cardiac disease risk. While results are broadly consistent with our prior study, we report that, with updated cardiac dosimetry, risks of cardiac disease are significantly higher in two dose and volume categories and slopes of the Dm-specific RT-response relationships are steeper. These data support the use of contemporary RT to achieve lower heart doses for pediatric patients, particularly those requiring chest-directed RT.

Aortic root replacement with Medtronic Freestyle bioprosthesis: 25-year experience

BACKGROUND

Stentless porcine bioprothesis is a surgical strategy to treat aortic root disease. Use has been limited due to the concern for long-term valve degeneration. This study evaluated the perioperative and late outcomes of patients with aortic root disease requiring root replacement.

METHODS

A total of 409 patients underwent aortic root replacement by a single surgeon using a stentless porcine bioroot between February 1996 and May 2020. The cohort was divided into two groups (age ≤65 and >65 years). Descriptive statistics were used to analyze the data and Kaplan-Meier curves used to evaluate long-term outcomes.

RESULTS

Patients age >65 years were more likely to be female (p = .01), have hypertension (p = .01), require circulatory arrest (p = .01), and have concomitant coronary artery bypass grafting (CABG) (p = .04). Baseline creatinine >1.8 (p = .20), diabetes (p = .06), and ejection fraction (p = .20) were similar between groups. The 1-, 5-, and 10-year survival for patients age ≤65 years were 92%, 87%, and 69%, respectively, significantly better than patients age >65 (88%, 73%, and 43%, respectively) (p < .01, Figure 1). The 1-, 5-, and 10-year freedom from reoperation for patients ≤65 years were 99%, 97%, and 93% versus 99%, 98%, and 96% in patients age >65 years, respectively (p = .24).

CONCLUSION

Patients with aortic root disease can be treated with acceptable perioperative outcomes, long-term survival, and low reoperation rates using a stentless porcine bioprothesis. It should be considered irrespective of age due to its excellent durability and freedom from anti-coagulation requirement.

Development and Validation of a Breast Cancer Risk Prediction Model for Childhood Cancer Survivors Treated With Chest Radiation: A Report From the Childhood Cancer Survivor Study and the Dutch Hodgkin Late Effects and LATER Cohorts

PURPOSE

Women treated with chest radiation for childhood cancer have one of the highest risks of breast cancer. Models producing personalized breast cancer risk estimates applicable to this population do not exist. We sought to develop and validate a breast cancer risk prediction model for childhood cancer survivors treated with chest radiation incorporating treatment-related factors, family history, and reproductive factors.

METHODS

Analyses were based on multinational cohorts of female 5-year survivors of cancer diagnosed younger than age 21 years and treated with chest radiation. Model derivation was based on 1,120 participants in the Childhood Cancer Survivor Study diagnosed between 1970 and 1986, with median attained age 42 years (range 20-64) and 242 with breast cancer. Model validation included 1,027 participants from three cohorts, with median age 32 years (range 20-66) and 105 with breast cancer.

RESULTS

The model included current age, chest radiation field, whether chest radiation was delivered within 1 year of menarche, anthracycline exposure, age at menopause, and history of a first-degree relative with breast cancer. Ten-year risk estimates ranged from 2% to 23% for 30-year-old women (area under the curve, 0.63; 95% CI, 0.50 to 0.73) and from 5% to 34% for 40-year-old women (area under the curve, 0.67; 95% CI, 0.54 to 0.84). The highest risks were among premenopausal women older than age 40 years treated with mantle field radiation within a year of menarche who had a first-degree relative with breast cancer. It showed good calibration with an expected-to-observed ratio of the number of breast cancers of 0.92 (95% CI, 0.74 to 1.16).

CONCLUSION

Breast cancer risk varies among childhood cancer survivors treated with chest radiation. Accurate risk prediction may aid in refining surveillance, counseling, and preventive strategies in this population.

Late morbidity and mortality among survivors of neuroblastoma treated with contemporary therapy: A report from the Childhood Cancer Survivor Study

10044

Background: Survival rates for neuroblastoma vary widely based on risk group. Therapies have evolved over the past four decades to de-intensify treatment for individuals with low/intermediate risk disease and intensify therapy for those with high risk disease. Risk stratification is predicted to result in differential outcomes in late morbidity and mortality; the magnitude of these differences has not been well studied. Methods: We evaluated late mortality, subsequent malignant neoplasms (SMN) and chronic health conditions (CHC) graded according to CTCAE v4.03 among 491 5-year CCSS survivors of neuroblastoma diagnosed 1987-1999 at ≥1 year of age. Using age, stage at diagnosis, and treatment, survivors were classified into risk groups (low [n=182]; intermediate [n=70]; high [n=239]). Standardized mortality ratios (SMR) and standardized incidence ratios (SIR) of SMN were calculated using rates from NCHS and SEER, respectively. Cox regression models estimated hazard ratios (HR) and 95% confidence intervals (CI) for CHC compared to 1,029 CCSS siblings. Results: Among survivors (48% male; median age 22 years, range 7-42; median follow-up 19 years, range 5-29), 80.4% with low risk disease were treated with surgery alone, while 77.8% with high risk disease received surgery, radiation, chemotherapy ± transplant. The 15-year cumulative incidence of all-cause mortality was 9.2% (CI: 7.1-11.4), with a recurrence-related mortality of 7.3% (CI: 5.3-9.3) and SMN-related mortality of 0.3% (CI: 0-0.7). All-cause mortality was significantly higher in all risk groups: (low, SMR=5.8 [CI: 2.6-13.0]; intermediate, SMR=5.7 [CI: 1.4-23.5]; high, SMR=38.6 [CI: 27.9-53.5]). The risk of SMN was elevated among high risk survivors (SIR=25.1, CI: 16.7-37.6), but did not differ from the US population for survivors of low or intermediate risk disease. Table describes the HR of CHCs (grades 1-5 and 3-5) in survivors, by risk group, as compared with siblings, as well as categories of CHCs for which survivors were at increased risk. Conclusions: Long-term survivors of neuroblastoma have a high risk of late morbidity and mortality; risk is particularly pronounced among survivors of high risk disease. Vigilant lifelong medical surveillance will be required for this relatively young population as they age.[Table: see text]

Low-dose radiation to cardiac substructures and late-onset cardiac disease: A report from the Childhood Cancer Survivor Study (CCSS)

10027

Background: Thoracic radiotherapy (RT) is a risk factor for cardiac disease among survivors of childhood cancer based on studies considering RT doses to the entire heart. Dose to specific cardiac substructures may provide more precise dose-response associations to guide RT planning. We report associations between RT dose to cardiac substructures and risk of specific cardiac outcomes. Methods: We determined the cumulative incidences of CTCAE grade 3 – 5 coronary artery disease (CAD), heart failure (HF), and valvular disease (VD) among 25,481 5-year childhood cancer survivors diagnosed 1970 – 1999 in the CCSS. Median age at diagnosis was 6.1 years (0 – 20 years) and at last follow-up 29.8 years (5.6 – 65.9 years). For the 12,228 individuals receiving RT, fields were reconstructed on an age scaled computational phantom. Mean doses to the entire heart, cardiac chambers, valves, and left main, anterior descending (LAD), circumflex, and right coronary (RCA) arteries were estimated. Adjusted piecewise exponential models (including cumulative anthracycline dose) evaluated associations between mean RT dose to each structure and outcomes. Results: At 30 years from diagnosis, the cumulative incidences of grades 3 – 5 CAD, HF, and VD were 2.3% (95% CI 2.0 – 2.5), 2.6% (95% CI 2.4 – 2.9), and 0.6% (95% CI 0.5 – 0.8) respectively. Low dose RT (mean 5 – 9.9 Gy) to the RCA (relative rate [RR] = 2.6, 95% CI 1.6 – 4.1, p < 0.001), LAD (RR = 1.9, 95% CI 1.1 – 3.3, p = 0.019), and left ventricle (RR = 2.2, 95% CI 1.3 – 3.7, p = 0.002) was associated with increased risk of CAD relative to those not exposed; mean dose of 5 – 9.9 Gy to the entire heart was not (RR = 1.1, 95% CI = 0.8 – 1.6, p = 0.59). Table shows the associated cumulative incidences of CAD for these structures. Mean RT doses of 5 – 9.9 Gy to the aortic valve (RR = 4.6, 95% CI 1.5 – 14.0, p = 0.008) and tricuspid valve (RR = 5.5, 95% CI 2.0 – 15.1, p = 0.001) were associated with risk of VD compared to those with no RT; mean heart dose 5 – 9.9 Gy was not (RR = 0.6, 95% CI = 0.2 – 1.3, p = 0.16). No cardiac structure was significantly associated with an increased risk of HF at a mean dose of 5 – 9.9 Gy. Mean RT doses below 5 Gy were not associated with increased risks of CAD, HF, or VD; doses ≥10 Gy to nearly all substructures and the entire heart were. Conclusions: Low dose RT to the coronary arteries and cardiac valves (5 – 9.9 Gy) from RT is associated with increased risk of CAD and VD, respectively. Sensitivity to low dose RT may vary across the heart and doses to specific structures may be more predictive of late cardiac disease than whole heart dose. These data can guide RT planning to prioritize substructures for avoidance.[Table: see text]

Efficacy of clinical breast examination in chest-irradiated female survivors of childhood Hodgkin lymphoma (HL)

10028

Background: Female survivors of childhood HL treated with ≥10 Gy of chest radiation are at high risk for breast cancer (BC). The Children’s Oncology Group (COG) guidelines recommend CBE annually starting at puberty and then semiannually from age 25, plus lifetime annual mammography (MAM) and breast Magnetic Resonance Imaging (MRI) starting 8y after chest radiation or age 25, whichever is later. While imaging-based screening recommendations are largely consistent with US guidelines for women at high BC risk, only the COG guidelines recommend CBE. The benefits of lifetime CBE starting from puberty for life in chest-irradiated HL survivors is unknown. Methods: Life-years (LYs) and lifetime BC mortality risk were estimated from a simulated cohort of 5-million HL survivors using the data from 5y female survivors of HL in the Childhood Cancer Survivor Study (CCSS) treated with ≥10 Gy of chest radiation. The simulated cohort underwent annual MAM+MRI from age 25 for life, with and without annual CBE from age 11 (presumed age of puberty) to age 24 and with and without semiannual CBE from age 25 for life with 100% adherence. BC included in-situ and invasive BC. Treatment-related BC incidence and non-BC mortality risks were estimated from the CCSS data. Risks at age <25 were extrapolated from the CCSS estimates while risks beyond age 50 were extrapolated additionally using the US population rates. CBE sensitivity (17.8%, in-situ and invasive BC) and specificity (98%) and MAM+MRI sensitivity (84.2-86.0%, in-situ; 96.7-97.1%, invasive) and specificity (75.3%) were obtained from the medical literature. Results: The CCSS cohort included 1057 female HL survivors. BC (all invasive) developed in three patients at age <25 (ages: 23, 24, 24). In the simulated cohort receiving no screening, lifetime BC risk was 40.8% and BC mortality was 17.5%. HL survivors around age 50 were at a 7.4-fold higher risk of developing BC and a 5.2-fold higher risk of non-BC mortality when compared with the general population. Compared to no annual CBE for ages 11-24y, undergoing annual CBE did not increase gains in LYs or reduce lifetime BC mortality relative to no screening (Table). Among those who survived to age ≥25, undergoing semiannual CBE from age 25 for life compared to no semiannual CBE also resulted in little gain in LYs or reduction in lifetime BC mortality relative to no screening. Conclusions: Lifetime CBE starting at puberty in conjunction with MAM+MRI appears to add little survival benefits compared with no CBE, suggesting that COG guidelines may be revised without adverse effect on long-term outcomes for chest-irradiated female survivors of childhood HL.[Table: see text]

Efficacy and cost-effectiveness of breast cancer (BC) screening in female survivors of childhood Hodgkin lymphoma (HL)

6593

Background: Female childhood HL survivors treated with ≥10 Gy of chest radiation are at high risk of developing BC. The Children’s Oncology Group (COG) guidelines recommend lifetime annual mammography (MAM) and breast Magnetic Resonance Imaging (MRI) starting 8y after chest radiation or age 25, whichever is later, and clinical breast examination (CBE) annually from puberty and semiannually from age 25. Initial model results suggest that CBE adds no survival benefit in this cohort. Digital breast tomosynthesis (DBT) is increasingly replacing digital MAM in clinical practice. Here, we present the efficacy and cost-effectiveness of COG’s imaging-based screening recommendations. Methods: Life-years (LYs), quality-adjusted LYs (QALYs), BC mortality, and costs (2017 U.S.$) were estimated from simulating the lifetimes of 5-million chest-irradiated 25y old HL survivors who underwent BC screening with each of the following strategies: annual digital MAM, MRI, MAM+MRI, annual DBT or DBT+MRI from age 25 onward. Treatment-related BC risk (in-situ and invasive) and non-BC mortality were estimated from female 5y HL survivors in the Childhood Cancer Survivor Study and from U.S. population rates. Test sensitivity was 70-74% for MAM (based on prior HL studies) and 89% for DBT and MRI (based on women at high risk of de novo BC). Costs and quality of life weights were obtained from medical literature. Results: For HL survivors with no screening, lifetime BC risk was 42.7% and BC mortality was 18.1%. BC risk and non-BC mortality were, respectively, 7.4- and 5.2-fold higher at age 50 in HL survivors relative to the general population. Screening at ages 25-74 had similar LY gain and BC mortality reduction compared to lifetime screening; hence, we focused on screening for ages 25-74. For all strategies screening provided LY gain of 0.34-0.47 and reduced BC mortality by 6.7-9.8% compared with no screening; incremental cost-effectiveness ratio (ICER), or cost per QALY gained, for MAM alone was $58,726 and for DBT alone was $62,989. ICER of adding MRI to MAM ($385,285) or to DBT ($513,358) indicated lower cost-effectiveness of supplemental MRI (Table). Conclusions: Annual screening at ages 25-74y in chest-irradiated HL survivors appears beneficial. Using $100K per QALY gained as cost-effectiveness threshold, annual MAM or DBT are more cost-effective, whereas adding MRI to MAM is less cost-effective.[Table: see text]

Evaluation of disease staging and chemotherapeutic response in non-small cell lung cancer from patient tumor-derived metabolomic data

OBJECTIVES

Despite extensive effort, the search for clinically-relevant metabolite biomarkers for early detection, disease monitoring, and outcome prediction in lung cancer remains unfulfilled. Although biofluid evaluation has been explored, the complexity inherent in metabolite data and the dynamic discrepancy between metabolites in biofluids vs. tumor tissue have prevented conclusive results. This proof-of-concept study explored models predictive of staging and chemotherapy response based on metabolomic analysis of fresh, patient-derived non-small cell lung cancer (NSCLC) core biopsies.

MATERIALS AND METHODS

Samples (n = 36) were evaluated with high-resolution 2DLC-MS/MS and ¹³C-glucose enrichment, and the data were comprehensively analyzed with machine learning techniques. Patients were categorized as Disease-Control (DC) [encompassing complete-response (CR), partial-response (PR), and stable-disease (SD)] and Progressive-Disease (PD) in terms of first-line chemotherapy. Four major types of learning methods (partial least squares discriminant analysis (PLS-DA), support vector machines (SVM), artificial neural networks, and random forests (RF)) were applied to differentiate between positive (DC and CR/PR) and poor (PD and SD/PD) responses, and between stage I/II/III and stage IV disease. Models were trained with forward feature selection based on variable importance and tested on validation subsets.

RESULTS

The models predicted patient classifications in the validation subsets with AUC (95 % CI): DC vs. PD (SVM), 0.970(0.961-0.979); CR/PR vs. SD/PD (PLS-DA), 0.880(0.865-0.895); stage I/II/III vs. IV (SVM), 0.902(0.880-0.924). Highest performing model was SVM for DC vs. PD (balanced accuracy = 0.92; kappa = 0.74).

CONCLUSION

This study illustrates a comprehensive evaluation of patient tumor-specific metabolic profiles, with the potential to identify disease stage and predict response to first-line chemotherapy.

Smoking, Radiation Therapy, and Contralateral Breast Cancer Risk in Young Women

Evidence is mounting that cigarette smoking contributes to second primary contralateral breast cancer (CBC) risk. Whether radiation therapy (RT) interacts with smoking to modify this risk is unknown. In this multicenter, individually-matched case-control study, we examined the association between RT, smoking, and CBC risk. The study included 1,521 CBC cases and 2,212 controls with unilateral breast cancer, all diagnosed with first invasive breast cancer between 1985-2008 at age <55 years. Absorbed radiation doses to contralateral breast regions were estimated with thermoluminescent dosimeters in tissue-equivalent anthropomorphic phantoms and smoking history was collected by interview. Rate ratios (RRs) and 95% confidence intervals (CIs) for CBC risk were estimated by multivariable conditional logistic regression. There was no interaction between any measure of smoking with RT to increase CBC risk (eg, the interaction of continuous RT dose with smoking at first breast cancer diagnosis [ever/never]: RR = 1.00, 95% CI = 0.89-1.14; continuous RT dose with years smoked: RR = 1.00, 95% CI = 0.99-1.01; and continuous RT dose with lifetime pack-years: RR = 1.00, 95% CI = 0.99-1.01). There was no evidence that RT further increased CBC risk in young women with first primary breast cancer who were current smokers or had smoking history.

Impact of Risk-Adapted Therapy for Pediatric Hodgkin Lymphoma on Risk of Long-Term Morbidity: A Report From the Childhood Cancer Survivor Study

PURPOSE

To determine the incidence of serious chronic health conditions among survivors of pediatric Hodgkin lymphoma (HL), compare by era of therapy and by selected cancer therapies, and provide estimates of risks associated with contemporary therapy.

METHODS

Assessing 2,996 5-year HL survivors in the Childhood Cancer Survivor Study diagnosed from 1970 to 1999, we examined the cumulative incidence of severe to fatal chronic conditions (grades 3-5) using self-report conditions, medically confirmed subsequent malignant neoplasms, and cause of death based on the National Death Index. We used multivariable regression models to estimate hazard ratios (HRs) per decade and by key treatment exposures.

RESULTS

HL survivors were of a mean age of 35.6 years (range, 12-58 years). The cumulative incidence of any grade 3-5 condition by 35 years of age was 31.4% (95% CI, 29.2 to 33.5). Females were twice as likely (HR, 2.1; 95% CI, 1.8 to 2.4) to have a grade 3-5 condition compared with males. From the 1970s to the 1990s, there was a 20% reduction (HR, 0.8; 95% CI, 0.7 to 0.9) in decade-specific risk of a grade 3-5 condition (P trend = .002). In survivors who had a recurrence and/or hematopoietic cell transplant, the risk of a grade 3-5 condition was substantially elevated, similar to that of survivors treated with high-dose, extended-field radiotherapy (HR, 1.2; 95% CI, 0.9 to 1.5). Compared with survivors treated with chest radiotherapy ≥ 35 Gy in combination with an anthracycline or alkylator, a contemporary regimen for low-intermediate risk HL was estimated to lead to a 40% reduction in risk of a grade 3-5 condition (HR, 0.6; 95% CI, 0.4 to 0.8).

CONCLUSION

This study demonstrates that risk-adapted therapy for pediatric HL has resulted in a significant reduction in serious long-term outcomes.

Novel Opiate-Free Anesthetic Technique for Major Urologic Procedures

OBJECTIVES

We postulated that an opiate-free (OF) general anesthesia (GA) technique could adequately control a patient's pain without adversely affecting recovery. We compared patients undergoing major urologic procedures with and without opiate-based GA.

METHODS

A propensity-matched analysis was performed comparing hospital length of stay, postoperative nausea and vomiting, ileus occurrence, postanesthesia care unit, and total opiate consumption, as well as sedation and hemodynamic variables. The data are expressed as medians and were analyzed with the Wilcoxon rank-sum test. P < 0.05 indicate statistical significance.

RESULTS

In total, 166 patients were evaluated in both the OF group and the opiate-based treatment group. American Society of Anesthesiologists classification and age were comparable, with most surgeries being laparoscopic and confined to the bladder, kidney, and prostate gland. The median opiate consumption in morphine equivalents in the postanesthesia care unit was 7.7 mg (range 5-11.7 mg) for the OF cohort versus 11.7 mg (range 5-17.3 mg) for the control group (P < 0.001). Similarly, the median total postoperative opiate consumption in morphine equivalents was 23.9 mg (range 13.8-42.4 mg) for the OF group compared with 32.1 mg (range 17.38-57.51 mg) for the control group (P = 0.0081). The median hospital length of stay for the OF group was 1.4 days (range 1.2-2.3 days) versus 1.3 days (range 1.2-2.4 days) for the control group (P = 0.8466).

CONCLUSIONS

There was a statistically significant difference in opiate consumption postoperatively for patients who underwent an OF technique compared with a conventional opiate-based technique. This technique appears to be a possible alternative approach, without any apparent untoward consequences during admission.

Radiation Dose and Volume to the Pancreas and Subsequent Risk of Diabetes Mellitus: A Report from the Childhood Cancer Survivor Study

BACKGROUND

Childhood cancer survivors exposed to abdominal radiation (abdRT) are at increased risk for diabetes mellitus, but the association between risk and radiation dose and volume is unclear.

METHODS

Participants included 20 762 5-year survivors of childhood cancer (4568 exposed to abdRT) and 4853 siblings. For abdRT, we estimated maximum dose to abdomen; mean doses for whole pancreas, pancreatic head, body, tail; and percent pancreas volume receiving no less than 10, 20, and 30 Gy. Relative risks (RRs) were estimated with a Poisson model using generalized estimating equations, adjusted for attained age. All statistical tests were two-sided.

RESULTS

Survivors exposed to abdRT (median age = 31.6 years, range = 10.2-58.3 years) were 2.92-fold more likely than siblings (95% confidence interval [CI] = 2.02 to 4.23) and 1.60-times more likely than survivors not exposed to abdRT (95%CI = 1.24 to 2.05) to develop diabetes. Among survivors treated with abdRT, greater attained age (RRper 10 years = 2.11, 95% CI = 1.70 to 2.62), higher body mass index (RRBMI 30+ = 5.00, 95% CI = 3.19 to 7.83 with referenceBMI 18.5-24.9), and increasing pancreatic tail dose were associated with increased diabetes risk in a multivariable model; an interaction was identified between younger age at cancer diagnosis and pancreatic tail dose with much higher diabetes risk associated with increasing pancreatic tail dose among those diagnosed at the youngest ages (P < .001). Radiation dose and volume to other regions of the pancreas were not statistically significantly associated with risk.

CONCLUSIONS

Among survivors treated with abdRT, diabetes risk was associated with higher pancreatic tail dose, especially at younger ages. Targeted interventions are needed to improve cardiometabolic health among those at highest risk.

Development and validation of an age-scalable cardiac model with substructures for dosimetry in late-effects studies of childhood cancer survivors

BACKGROUND AND PURPOSE

Radiation therapy is a risk factor for late cardiac disease in childhood cancer survivors. Several pediatric cohort studies have established whole heart dose and dose-volume response models. Emerging data suggest that dose to cardiac substructures may be more predictive than whole heart metrics. In order to develop substructure dose-response models, the heart model previously used for pediatric cohort dosimetry needed enhancement and substructure delineation.

METHODS

To enhance our heart model, we combined the age-scalable capability of our computational phantom with the anatomically-delineated (with substructures) heart models from an international humanoid phantom series. We examined cardiac volume similarity/overlap between registered age-scaled phantoms (1, 5, 10, and 15 years) with the enhanced heart model and the reference phantoms of the same age; dice similarity coefficient (DSC) and overlap coefficient (OC) were calculated for each matched pair. To assess the accuracy of our enhanced heart model, we compared doses from computed tomography-based planning (ground truth) with reconstructed heart doses. We also compared doses calculated with the prior and enhanced heart models for a cohort of nearly 5000 childhood cancer survivors.

RESULTS

We developed a realistic cardiac model with 14-substructures, scalable across a broad age range (1-15 years); average DSC and OC were 0.84 ± 0.05 and 0.90 ± 0.05, respectively. The average percent difference between reconstructed and ground truth mean heart doses was 4.2%. In the cohort dosimetry analysis, dose and dose-volume metrics were approximately 10% lower on average when the enhanced heart model was used for dose reconstructions.

CONCLUSION

We successfully developed and validated an anatomically realistic age-scalable cardiac model that can be used to establish substructure dose-response models for late cardiac disease in childhood cancer survivor cohorts.

Psychological, educational, and social late effects in adolescent survivors of Wilms tumor: A report from the Childhood Cancer Survivor Study

OBJECTIVE

To delineate the impact of treatment exposures and chronic health conditions on psychological, educational, and social outcomes in adolescent survivors of Wilms tumor.

METHODS

Parent reports from the Childhood Cancer Survivor Study were analyzed for 666 adolescent survivors of Wilms tumor and 698 adolescent siblings. Adjusting for race and household income, survivors were compared to siblings on the Behavior Problems Index and educational outcomes. Multivariable modified Poisson regression estimated relative risks (RR) for therapeutic exposures and chronic health conditions (CTCAE 4.03 graded) among survivors, adjusting for sex, race, income, and age at diagnosis.

RESULTS

Compared to siblings, adolescent survivors of Wilms tumor were more likely to take psychoactive medication (9.4% vs. 5.1%, p < 0.001) and utilize special education services (25.5% vs. 12.6%, p < 0.001) but did not differ significantly in emotional and behavioral problems. Survivors were less likely to be friendless (7.2% vs. 10.1%, p = 0.04) but were more likely to have difficulty getting along with friends (14.5% vs. 7.8%, p < 0.001). Among survivors, use of special education services was associated with abdomen plus chest radiation (RR = 1.98, CI:1.18-3.34). Those with grade 2-4 cardiovascular conditions had higher risk for anxiety/depression (RR = 1.95, CI:1.19-3.19), headstrong behaviors (RR = 1.91, CI:1.26-2.89), and inattention (RR = 1.56, CI:1.02-2.40).

CONCLUSIONS

Adolescent survivors of Wilms tumor were similar to siblings with respect to mental health concerns overall but were more likely to require special education. Monitoring of psychosocial and academic problems through adolescence is warranted, especially among those treated with radiation to the abdomen plus chest or with cardiac conditions.

Development of an age-scalable 3D computational phantom in DICOM standard for late effects studies of childhood cancer survivors

Purpose:

We previously developed an age-scalable 3D computational phantom that has been widely used for retrospective whole-body dose reconstructions of conventional two-dimensional historic radiation therapy (RT) treatments in late effects studies of childhood cancer survivors. This phantom is modeled in the FORTRAN programming language and is not readily applicable for dose reconstructions for survivors treated with contemporary RT whose treatment plans were designed using computed tomography images and complex treatment fields. The goal of this work was to adapt the current FORTRAN model of our age-scalable computational phantom into Digital Imaging and Communications in Medicine (DICOM) standard so that it can be used with any treatment planning system (TPS) to reconstruct contemporary RT. Additionally, we report a detailed description of the phantom’s age-based scaling functions, information that was not previously published.

Method:

We developed a Python script that adapts our phantom model from FORTRAN to DICOM. To validate the conversion, we compared geometric parameters for the phantom modeled in FORTRAN and DICOM scaled to ages 1 month, 6 months, 1, 2, 3, 5, 8, 10, 15, and 18 years. Specifically, we calculated the percent differences between the corner points and volume of each body region and the normalized mean square distance (NMSD) between each of the organs. In addition, we also calculated the percent difference between the heights of our DICOM age-scaled phantom and the heights (50th percentile) reported by the World Health Organization (WHO) and Centers for Disease Control and Prevention (CDC) for male and female children of the same ages. Additionally, we calculated the difference between the organ masses for our DICOM phantom and the organ masses for two reference phantoms (from International Comission on Radiation Protection (ICRP) 89 and the University of Florida/National Cancer Institute reference hybrid voxel phantoms) for ages newborn, 1, 5, 10, 15 and adult. Lastly, we conducted a feasibility study using our DICOM phantom for organ dose calculations in a commercial TPS. Specifically, we simulated a 6 MV photon right-sided flank field RT plan for our DICOM phantom scaled to age 3.9 years; treatment field parameters and age were typical of a Wilms tumor RT treatment in the Childhood Cancer Survivor Study. For comparison, the same treatment was simulated using our in-house dose calculation system with our FORTRAN phantom. The percent differences (between FORTRAN and DICOM) in mean dose and percent of volume receiving dose ⩾5 Gy were calculated for two organs at risk, liver and pancreas.

Results:

The percent differences in corner points and the volumes of head, neck, and trunk body regions between our phantom modeled in FORTRAN and DICOM agreed within 3%. For all of the ages, the NMSDs were negliglible with a maximum NMSD of 7.80 × 10⁻² mm for occiptital lobe of 1 month. The heights of our age-scaled phantom agreed with WHO/CDC data within 7% from infant to adult, and within 2% agreement for ages 5 years and older. We observed that organ masses in our phantom are less than the organ masses for other reference phantoms. Dose calculations done with our in-house calculation system (with FORTRAN phantom) and commercial TPS (with DICOM phantom) agreed within 7%.

Conclusion:

We successfully adapted our phantom model from the FORTRAN language to DICOM standard and validated its geometric consistency. We also demonstrated that our phantom model is representative of population height data for infant to adult, but that the organ masses are smaller than in other reference phantoms and need further refinement. Our age-scalable computational phantom modeled in DICOM standard can be scaled to any age at RT and used within a commercial TPS to retrospectively reconstruct doses from contemporary RT in childhood cancer survivors.

Combined Genome and Transcriptome Analyses of the Ciliate Schmidingerella arcuata (Spirotrichea) Reveal Patterns of DNA Elimination, Scrambling, and Inversion

Schmidingerella arcuata is an ecologically important tintinnid ciliate that has long served as a model species in plankton trophic ecology. We present a partial micronuclear genome and macronuclear transcriptome resource for S. arcuata, acquired using single-cell techniques, and we report on pilot analyses including functional annotation and genome architecture. Our analysis shows major fragmentation, elimination, and scrambling in the micronuclear genome of S. arcuata. This work introduces a new nonmodel genome resource for the study of ciliate ecology and genomic biology and provides a detailed functional counterpart to ecological research on S. arcuata.

Subsequent Neoplasm Risk Associated With Rare Variants in DNA Damage Response and Clinical Radiation Sensitivity Syndrome Genes in the Childhood Cancer Survivor Study

PURPOSE

Radiotherapy for childhood cancer is associated with elevated subsequent neoplasm (SN) risk, but the contribution of rare variants in DNA damage response and radiation sensitivity genes to SN risk is unknown.

PATIENTS AND METHODS

We conducted whole-exome sequencing in a cohort of childhood cancer survivors originally diagnosed during 1970 to 1986 (mean follow-up, 32.7 years), with reconstruction of doses to body regions from radiotherapy records. We identified patients who developed SN types previously reported to be related to radiotherapy (RT-SNs; eg, basal cell carcinoma [BCC], breast cancer, meningioma, thyroid cancer, sarcoma) and matched controls (sex, childhood cancer type/diagnosis, age, SN location, radiation dose, survival). Conditional logistic regression assessed SN risk associated with potentially protein-damaging rare variants (SnpEff, ClinVar) in 476 DNA damage response or radiation sensitivity genes with exact permutation-based P values using a Bonferroni-corrected significance threshold of P < 8.06 × 10^-5.

RESULTS

Among 5,105 childhood cancer survivors of European descent, 1,108 (21.7%) developed at least 1 RT-SN. Out-of-field RT-SN risk, excluding BCC, was associated with homologous recombination repair (HRR) gene variants (patient cases, 23.2%; controls, 10.8%; odds ratio [OR], 2.6; 95% CI, 1.7 to 3.9; P = 4.79 × 10^-5), most notably but nonsignificantly for FANCM (patient cases, 4.0%; matched controls, 0.6%; P = 9.64 × 10^-5). HRR variants were not associated with likely in/near-field RT-SNs, excluding BCC (patient cases, 12.7%; matched controls, 12.9%; P = .92). Irrespective of radiation dose, risk for RT-SNs was also associated with EXO1 variants (patient cases, 1.8%; controls, 0.4%; P = 3.31 × 10^-5), another gene implicated in DNA double-strand break repair.

CONCLUSION

In this large-scale discovery study, we identified novel associations between RT-SN risk after childhood cancer and potentially protein-damaging rare variants in genes involved in DNA double-strand break repair, particularly HRR. With replication, these results could affect screening recommendations for childhood cancer survivors and risk-benefit assessments of treatment approaches.

Dose-volume effects of breast cancer radiation therapy on the risk of second oesophageal cancer

PURPOSE

To investigate the relationship between oesophagus dose-volume distribution and long-term risk of oesophageal cancer after radiation therapy for breast cancer.

MATERIALS AND METHODS

In a case-control study nested within a cohort of 289,748 ≥5-year survivors of female breast cancer treated in 1943-2003 in five countries, doses to the second primary cancer (D_SPC) and individual dose-volume histograms (DVH) to the entire oesophagus were reconstructed for 252 oesophageal cancer cases and 488 matched controls (median follow-up time: 13, range: 5-37 years). Using conditional logistic regression, we estimated excess odds ratios (EOR) of oesophageal cancer associated with DVH metrics. We also investigated whether DVH metrics confounded or modified D_SPC-related -risk estimates.

RESULTS

Among the DVH metrics evaluated, median dose (D_median) to the entire oesophagus had the best statistical performance for estimating risk of all histological types combined (EOR/Gy = 0.071, 95% confidence interval [CI]: 0.018 to 0.206). For squamous cell carcinoma, the most common subtype, the EOR/Gy for D_median increased by 31% (95% CI: 3% to 205%) for each increment of 10% of V30 (p = 0.02). Adjusting for DVH metrics did not materially change the EOR/Gy for D_SPC, but there was a borderline significant positive interaction between D_SPC and V30 (p = 0.07).

CONCLUSION

This first study investigating the relationship between oesophagus dose-volume distribution and oesophageal cancer risk showed an increased risk per Gy for D_median with larger volumes irradiated at high doses. While current techniques allows better oesophagus sparing, constraints applied to D_median and V30 could potentially further reduce the risk of oesophageal cancer.

A Mail Audit Independent Peer Review System for Dosimetry Verification of a Small Animal Irradiator

Dedicated precision orthovoltage small animal irradiators have become widely available in the past decade and are commonly used for radiation biology research. However, there is a lack of dosimetric standardization among these irradiators, which affects the reproducibility of radiation-based animal studies. The purpose of this study was to develop a mail-based, independent peer review system to verify dose delivery among institutions using X-RAD 225Cx irradiators (Precision X-Ray, North Branford, CT). A robust, user-friendly mouse phantom was constructed from high-impact polystyrene and designed with dimensions similar to those of a typical laboratory mouse. The phantom accommodates three thermoluminescent dosimeters (TLDs) to measure dose. The mouse peer review system was commissioned in a small animal irradiator using anterior-posterior and posterior-anterior beams of 225 kVp and then mailed to three institutions to test the feasibility of the audit service. The energy correction factor for TLDs in the mouse phantom was derived to validate the delivered dose using this particular animal irradiation system. This feasibility study indicated that three institutions were able to deliver a radiation dose to the mouse phantom within ±10% of the target dose. The developed mail audit independent peer review system for the verification of mouse dosimetry can be expanded to characterize other commercially available orthovoltage irradiators, thereby enhancing the reproducibility of studies employing these irradiators.

Comparison of Radiation Dose Reconstruction Methods to Investigate Late Adverse Effects of Radiotherapy for Childhood Cancer: A Report from the Childhood Cancer Survivor Study

Quantification of radiation dose to normal tissue during radiotherapy is critical for assessing risk for radiotherapy-related late effects, including subsequent neoplasms (SNs). Case-control studies of SNs typically reconstruct absorbed radiation dose to the specific SN location using individual treatment parameters. A simplified method estimates the maximum prescribed target dose to the body region in which the SN arises. We compared doses and risk estimates from these methods using data from case-control studies of subsequent brain tumors (64 cases, 244 controls) and breast cancer (94 cases, 358 controls) nested within the Childhood Cancer Survivor Study (≥5-year survivors of childhood cancer diagnosed 1970-1986). The weighted kappa statistic [95% confidence interval (CI)] evaluating agreement between categorical (>0-9.9/10-19.9/20-29.9/≥30 Gy) body-region and tumor location-specific doses was 0.95 (0.91-0.98) for brain and 0.76 (0.69-0.82) for breast. The body-region and location-specific doses were assigned to the same dose category for a smaller proportion of patients treated with fields delivering a heterogeneous dose across the tissue of interest (e.g., partial brain field = 57.1%; mantle field = 61.3%) than patients treated with fields delivering a more homogeneous dose (e.g., whole brain field = 100%). Excess odds ratios per Gy (95% CI) from conditional logistic regression were 1.25 (0.33-6.33) and 1.20 (0.31-6.14) for brain tumors and 0.21 (0.05-0.77) and 0.10 (0.02-0.44) for breast cancer, using location-specific and body-region doses, respectively. We observed that body-region doses can approximate location-specific doses when the tissue of interest is clearly in the radiation field or outside the treated body region. Agreement is lower when there is greater ambiguity of SN location relative to the treatment field.

Hypothalamic-Pituitary Disorders in Childhood Cancer Survivors: Prevalence, Risk Factors and Long-Term Health Outcomes

CONTEXT

Data on hypothalamic-pituitary (HP) disorders in systematically evaluated childhood cancer survivors are limited.

OBJECTIVE

To describe prevalence, risk factors, and associated adverse health outcomes of deficiencies in GH deficiency (GHD), TSH deficiency (TSHD), LH/FSH deficiency (LH/FSHD), and ACTH deficiency (ACTHD), and central precocious puberty (CPP).

DESIGN

Retrospective with cross-sectional health outcomes analysis.

SETTING

Established cohort; tertiary care center.

PATIENTS

Participants (N = 3141; median age, 31.7 years) were followed for a median 24.1 years.

MAIN OUTCOME MEASURE

Multivariable logistic regression was used to calculate ORs and 95% CIs for associations among HP disorders, tumor- and treatment-related risk factors, and health outcomes.

RESULTS

The estimated prevalence was 40.2% for GHD, 11.1% for TSHD, 10.6% for LH/FSHD, 3.2% for ACTHD, and 0.9% for CPP among participants treated with HP radiotherapy (n = 1089), and 6.2% for GHD, and <1% for other HP disorders without HP radiotherapy. Clinical factors independently associated with HP disorders included HP radiotherapy (at any dose for GHD, TSHD, LH/FSHD, >30 Gy for ACTHD), alkylating agents (GHD, LH/FSHD), intrathecal chemotherapy (GHD), hydrocephalus with shunt placement (GHD, LH/FSHD), seizures (TSHD, ACTHD), and stroke (GHD, TSHD, LH/FSHD, ACTHD). Adverse health outcomes independently associated with HP disorders included short stature (GHD, TSHD), severe bone mineral density deficit (GHD, LH/FSHD), obesity (LH/FSHD), frailty (GHD), impaired physical health-related quality of life (TSHD), sexual dysfunction (LH/FSHD), impaired memory, and processing speed (GHD, TSHD).

CONCLUSION

HP radiotherapy, central nervous system injury, and, to a lesser extent, chemotherapy are associated with HP disorders, which are associated with adverse health outcomes.

Association of Breast Cancer Risk After Childhood Cancer With Radiation Dose to the Breast and Anthracycline Use: A Report From the Childhood Cancer Survivor Study

IMPORTANCE

Chest irradiation for childhood cancer is associated with increases in breast cancer risk. Growing evidence suggests that anthracyclines increase this risk, but the outcome of combined anthracycline use and radiotherapy has not been studied.

OBJECTIVES

To evaluate breast cancer risk in childhood cancer survivors following radiotherapy and chemotherapy and assess whether risks varied by estrogen receptor (ER) status.

DESIGN, SETTING, AND PARTICIPANTS

In a North American hospital-based nested case-control study, a retrospective cohort of 14 358 five-year survivors of childhood cancer, diagnosed from 1970 to 1986 and followed up through December 31, 2016, was analyzed. Cases (n = 271) were defined as women with subsequent breast cancer. Controls (n = 1044) were matched 4:1 to cases by age at first cancer and duration of follow-up (± 2 years). Data analysis was conducted from September 2017 to July 2018.

EXPOSURES

Radiation dose to breast tumor site and ovaries and cumulative chemotherapy doses, including anthracyclines and alkylating agents.

MAIN OUTCOMES AND MEASURES

Odds ratios (ORs) for subsequent breast cancer by ER status.

RESULTS

A total of 271 women served as breast cancer cases (median age at first cancer diagnosis, 15 years [range, 3-20]; median age at breast cancer diagnosis, 39 years [range, 20-57]): 201 invasive (113 ER positive [ER+], 41 ER negative [ER-], and 47 unknown) and 70 in situ breast cancers. The OR for breast cancer increased with increasing radiation dose to the breast (OR per 10 Gy, 3.9; 95% CI, 2.5-6.5) and was similar for ER+ (OR per 10 Gy, 5.5; 95% CI, 2.8-12.6) and ER- (OR per 10 Gy, 4.8; 95% CI, 1.7-22.3) cancers. For women who received ovarian doses less than 1 Gy, the OR per 10 Gy to the breast was higher (OR, 6.8; 95% CI, 3.9-12.5) than for women who received ovarian doses greater than or equal to 15 Gy (OR, 1.4; 95% CI, 1.0-6.4). The OR for breast cancer increased with cumulative anthracycline dose (OR per 100 mg/m2, 1.23; 95% CI, 1.09-1.39; P < .01 for trend), and was 1.49 (95% CI, 1.21-1.83) for ER+ cancer vs 1.10 (95% CI, 0.84-1.45) for ER- cancers (P value for heterogeneity = .47). There was an additive interaction between radiotherapy and anthracycline treatment (P = .04) with the OR for the combined association between anthracycline therapy and breast radiation dose of 10 Gy or more (compared with 0 to less than 1 Gy) of 19.1 (95% CI, 7.6-48.0) vs 9.6 (95% CI, 4.4-20.7) without anthracycline use.

CONCLUSIONS AND RELEVANCE

This study provides the first evidence to date that the combination of anthracyclines and radiotherapy may increase breast cancer risks compared with use of neither treatment with a similar radiation dose response for ER+ and ER- cancers and possibly higher anthracycline risks for ER+ cancers. These results might help inform surveillance guidelines for childhood cancer survivors.

Solid organ transplantation after treatment for childhood cancer: a retrospective cohort analysis from the Childhood Cancer Survivor Study

BACKGROUND

Serious chronic medical conditions occur in childhood cancer survivors. We aimed to investigate incidence of and risk factors for end-organ damage resulting in registration on a waiting list for or receiving a solid organ transplantation and 5-year survival following these procedures.

METHODS

The Childhood Cancer Survivor Study (CCSS) is a retrospective cohort of individuals who survived at least 5 years after childhood cancer diagnosed at younger than 21 years of age, between Jan 1, 1970, and Dec 31, 1986, at one of 25 institutions in the USA. We linked data from CCSS participants treated in the USA diagnosed between Jan 1, 1970, and Dec 31, 1986 (without solid organ transplantation before cohort entry) to the Organ Procurement and Transplantation Network-a database of all US organ transplants. Eligible participants had been diagnosed with leukaemia, lymphoma, malignant CNS tumours, neuroblastoma, Wilms' tumours, and bone and soft tissue sarcomas. The two primary endpoints for each type of organ transplant were date of first registration of a transplant candidate on the waiting list for an organ and the date of the first transplant received. We also calculated the cumulative incidence of being placed on a waiting list or receiving a solid organ transplantation, hazard ratios (HRs) for identified risk factors, and 5-year survival following transplantation.

FINDINGS

Of 13 318 eligible survivors, 100 had 103 solid organ transplantations (50 kidney, 37 heart, nine liver, seven lung) and 67 were registered on a waiting list without receiving a transplant (21 kidney, 25 heart, 15 liver, six lung). At 35 years after cancer diagnosis, the cumulative incidence of transplantation or being on a waiting list was 0·54% (95% CI 0·40-0·67) for kidney transplantation, 0·49% (0·36-0·62) for heart, 0·19% (0·10-0·27) for liver, and 0·10% (0·04-0·16) for lung. Risk factors for kidney transplantation were unilateral nephrectomy (HR 4·2, 95% CI 2·3-7·7), ifosfamide (24·9, 7·4-83·5), total body irradiation (6·9, 2·3-21·1), and mean kidney radiation of greater than 15 Gy (>15-20 Gy, 3·6 [1·5-8·5]; >20 Gy 4·6 [1·1-19·6]); for heart transplantation, anthracycline and mean heart radiation of greater than 20 Gy (dose-dependent, both p<0·0001); for liver transplantation, dactinomycin (3·8, 1·3-11·3) and methotrexate (3·3, 1·0-10·2); for lung transplantation, carmustine (12·3, 3·1-48·9) and mean lung radiation of greater than 10 Gy (15·6, 2·6-92·7). 5-year overall survival after solid organ transplantation was 93·5% (95% CI 81·0-97·9) for kidney transplantation, 80·6% (63·6-90·3) for heart, 27·8% (4·4-59·1) for liver, and 34·3% (4·8-68·6) for lung.

INTERPRETATION

Solid organ transplantation is uncommon in ageing childhood cancer survivors. Organ-specific exposures were associated with increased solid organ transplantation incidence. Survival outcomes showed that solid organ transplantation should be considered for 5-year childhood cancer survivors with severe end-organ failure.

FUNDING

US National Institute of Health, American Lebanese Syrian Associated Charities, US Health Resources and Services Administration.

Leydig Cell Function in Male Survivors of Childhood Cancer: A Report From the St Jude Lifetime Cohort Study

PURPOSE

Direct assessment of Leydig cell function in childhood cancer survivors has been limited. The objectives of this study were to describe the prevalence of and risk factors for Leydig cell failure (LCF), Leydig cell dysfunction (LCD), and associated adverse health outcomes.

PATIENTS AND METHODS

In this retrospective study with cross-sectional health outcomes analysis, we evaluated 1,516 participants (median age, 30.8 years) at a median of 22.0 years after cancer diagnosis. LCF was defined as serum total testosterone less than 250 ng/dL (or 8.67 nmol/L) and luteinizing hormone greater than 9.85 IU/L, and LCD by testosterone as 250 ng/dL or greater and luteinizing hormone greater than 9.85 IU/L. Polytomous logistic regression evaluated associations with demographic and treatment-related risk factors. Log-binomial regression evaluated associations with adverse physical and psychosocial outcomes. Piecewise exponential models assessed the association with all-cause mortality.

RESULTS

The prevalence of LCF and LCD was 6.9% and 14.7%, respectively. Independent risk factors for LCF included an age of 26 years or older at assessment, testicular radiotherapy at any dose, and alkylating agents at cyclophosphamide equivalent doses of 4,000 mg/m² or greater. The risk increased with older age, higher doses of testicular radiotherapy, and cyclophosphamide equivalent doses. LCF was significantly associated with abdominal obesity, diabetes mellitus, erectile dysfunction, muscle weakness, and all-cause mortality. LCD was associated with unilateral orchiectomy and the same risk factors as LCF; no significant associations were found with adverse physical or psychosocial outcomes.

CONCLUSION

Older age, testicular radiotherapy, and exposure to alkylating agents were associated with LCF, which was associated with adverse physical and psychosexual outcomes. LCD, although having similar risk factors, was not associated with adverse health outcomes. Additional studies are needed to investigate the role of sex hormone replacement in mitigating the burden from adverse outcomes in survivors.

Association of a Pathway-Specific Genetic Risk Score With Risk of Radiation-Associated Contralateral Breast Cancer

IMPORTANCE

Radiation therapy for breast cancer is associated with increased risk of a second primary contralateral breast cancer, but the genetic factors modifying this association are not well understood.

OBJECTIVE

To determine whether a genetic risk score comprising single nucleotide polymorphisms in the nonhomologous end-joining DNA repair pathway is associated with radiation-associated contralateral breast cancer.

DESIGN, SETTING, AND PARTICIPANTS

This case-control study included a case group of women with contralateral breast cancer that was diagnosed at least 1 year after a first primary breast cancer who were individually matched to a control group of women with unilateral breast cancer. Inclusion criteria were receiving a first invasive breast cancer diagnosis prior to age 55 years between 1985 and 2008. Women were recruited through 8 population-based cancer registries in the United States, Canada, and Denmark as part of the Women's Environment, Cancer, and Radiation Epidemiology Studies I (November 2000 to August 2004) and II (March 2010 to December 2012). Data analysis was conducted from July 2017 to August 2019.

EXPOSURES

Stray radiation dose to the contralateral breast during radiation therapy for the first breast cancer. A novel genetic risk score comprised of genetic variants in the nonhomologous end-joining DNA repair pathway was considered the potential effect modifier, dichotomized as high risk if the score was above the median of 74 and low risk if the score was at or below the median.

MAIN OUTCOMES AND MEASURES

The main outcome was risk of contralateral breast cancer associated with stray radiation dose stratified by genetic risk score, age, and latency.

RESULTS

A total of 5953 women were approached for study participation, and 3732 women (62.7%) agreed to participate. The median (range) age at first diagnosis was 46 (23-54) years. After 5 years of latency or more, among women who received the first diagnosis when they were younger than 40 years, exposure to 1.0 Gy (to convert to rad, multiply by 100) or more of stray radiation was associated with a 2-fold increased risk of contralateral breast cancer compared with women who were not exposed (rate ratio, 2.0 [95% CI, 1.1-3.6]). The risk was higher among women with a genetic risk score above the median (rate ratio, 3.0 [95% CI, 1.1-8.1]), and there was no association among women with a genetic risk score below the median (rate ratio, 1.3 [95% CI, 0.5-3.7]). Among younger women with a high genetic risk score, the attributable increased risk for contralateral breast cancer associated with stray radiation dose was 28%.

CONCLUSIONS AND RELEVANCE

This study found an increased risk of contralateral breast cancer that was attributable to stray radiation exposure among women with a high genetic risk score and who received a first breast cancer diagnosis when they were younger than 40 years after 5 years or more of latency. This genetic risk score may help guide treatment and surveillance for women with breast cancer.

Adaptations to a Generalized Radiation Dose Reconstruction Methodology for Use in Epidemiologic Studies: An Update from the MD Anderson Late Effect Group

Epidemiologic studies that include patients who underwent radiation therapy for the treatment of cancer aim to quantify the relationship between radiotherapy and the risk of subsequent late effects. Because of the long follow-up period required to observe late effects, these studies are conducted retrospectively. The studies routinely include patients treated across numerous institutions using a wide range of technologies and represent treatments over several decades. As a result, determining the dose throughout the patient's body is uniquely challenging. Therefore, estimating doses throughout the patient's body for epidemiologic studies requires special methodologies that are generally applied to a wide range of radiotherapy techniques. Over ten years ago, the MD Anderson Late Effects Group described various dose reconstruction methods for therapeutic and diagnostic radiation exposure for epidemiologic studies. Here we provide an update to the most widely used dose reconstruction methodology for epidemiologic studies, analytical model calculations combined with a 3D age-specific computational phantom. In particular, we describe the various adaptations (and enhancements) of that methodology, as well as how they have been used in radiation epidemiology studies and may be used in future studies.

Quantification of DTI in the Pediatric Spinal Cord: Application to Clinical Evaluation in a Healthy Patient Population

BACKGROUND AND PURPOSE

The purpose of the study is to characterize diffusion tensor imaging indices in the developing spinal cord, evaluating differences based on age and cord region. Describing the progression of DTI indices in the pediatric cord increases our understanding of spinal cord development.

MATERIALS AND METHODS

A retrospective analysis was performed on DTI acquired in 121 pediatric patients (mean, 8.6 years; range, 0.3-18.0 years) at Monroe Carell Jr. Children's Hospital at Vanderbilt from 2017 to 2018. Diffusion-weighted images (15 directions; b = 750 s/mm²; slice thickness, 5 mm; in-plane resolution, 1.0 × 1.0 mm²) were acquired on a 3T scanner in the cervicothoracic and/or thoracolumbar cord. Manual whole-cord segmentation was performed. Images were masked and further segmented into cervical, upper thoracic, thoracolumbar, and conus regions. Analyses of covariance were performed for each DTI-derived index to investigate how age affects diffusion across cord regions, and 95% confidence intervals were calculated across age for each derived index and region. Post hoc testing was performed to analyze regional differences.

RESULTS

Analyses of covariance revealed significant correlations of age with axial diffusivity, mean diffusivity, and fractional anisotropy (all, P < .001). There were also significant differences among cord regions for axial diffusivity, radial diffusivity, mean diffusivity, and fractional anisotropy (all, P < .001).

CONCLUSIONS

This research demonstrates that diffusion evolves in the pediatric spinal cord during development, dependent on both cord region and the diffusion index of interest. Future research could investigate how diffusion may be affected by common pediatric spinal pathologies.

Hyperthyroidism After Radiation Therapy for Childhood Cancer: A Report from the Childhood Cancer Survivor Study

PURPOSE

The association of hyperthyroidism with exposure to ionizing radiation is poorly understood. This study addresses the risk of hyperthyroidism in relation to incidental therapeutic radiation dose to the thyroid and pituitary glands in a large cohort of survivors of childhood cancer.

METHODS AND MATERIALS

Using the Childhood Cancer Survivor Study's cohort of 5-year survivors of childhood cancer diagnosed at hospitals in the United States and Canada between 1970 and 1986, the occurrence of hyperthyroidism through 2009 was ascertained among 12,183 survivors who responded to serial questionnaires. Radiation doses to the thyroid and pituitary glands were estimated from radiation therapy records, and chemotherapy exposures were abstracted from medical records. Binary outcome regression was used to estimate prevalence odds ratios (ORs) for hyperthyroidism at 5 years from diagnosis of childhood cancer and Poisson regression to estimate incidence rate ratios (RRs) after the first 5 years.

RESULTS

Survivors reported 179 cases of hyperthyroidism, of which 148 were diagnosed 5 or more years after their cancer diagnosis. The cumulative proportion of survivors diagnosed with hyperthyroidism by 30 years after the cancer diagnosis was 2.5% (95% confidence interval [CI], 2.0%-2.9%) among those who received radiation therapy. A linear relation adequately described the thyroid radiation dose response for prevalence of self-reported hyperthyroidism 5 years after cancer diagnosis (excess OR/Gy, 0.24; 95% CI, 0.06-0.95) and incidence rate thereafter (excess RR/Gy, 0.06; 95% CI, 0.03-0.14) over the dose range of 0 to 63 Gy. Neither radiation dose to the pituitary gland nor chemotherapy was associated significantly with hyperthyroidism. Radiation-associated risk remained elevated >25 years after exposure.

CONCLUSIONS

Risk of hyperthyroidism after radiation therapy during childhood is positively associated with external radiation dose to the thyroid gland, with radiation-related excess risk persisting for >25 years. Neither radiation dose to the pituitary gland nor chemotherapy exposures were associated with hyperthyroidism among childhood cancer survivors through early adulthood.

Long term morbidity and mortality among survivors of infant neuroblastoma: A report from the Childhood Cancer Survivor Study (CCSS)

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Background: Infants with neuroblastoma typically have low-risk disease with excellent survival. Therapy has been de-intensified over time to minimize late effects, however the impact on survivors’ risk of late mortality, subsequent malignant neoplasms (SMN), and chronic health conditions (CHC) is unclear. Methods: We evaluated late mortality, SMNs and CHCs (graded according to CTCAE v4.03), overall and by diagnosis era, among 990 5-year neuroblastoma survivors diagnosed at < 1 year of age between 1970-1999. Cumulative mortality, standardized mortality ratios (SMR), and standardized incidence ratios (SIR) of SMNs were estimated using the National Death Index and SEER rates, respectively. Cox proportional hazards estimated hazard ratios (HR) and 95% confidence intervals (CI) for CHC, compared to 5,051 CCSS siblings. Results: Among survivors (48% female; median attained age: 24 years, range 6-46), there was increased treatment with surgery alone across the 1970s, 1980s and 1990s (21.5%, 35.3%, 41.1%, respectively), but decreased treatment with combination surgery + radiation (22.5%, 5.3%, 0.3%, respectively) and surgery + radiation + chemotherapy (28.7%, 14.7%, 9.3%, respectively). The 20-year cumulative mortality was 2.3% (95% CI, 1.4-3.8), primarily due to SMNs (SMRSMN= 10.0, 95% CI, 4.5-22.3). The 20-year cumulative incidence of SMN was 1.2% (95% CI, 0.3-3.2), 2.5% (95% CI, 1.3-4.4), and zero for those diagnosed in the 1970s, 1980s, and 1990s, respectively. SIR was highest for renal SMNs (SIR 12.5, 95% CI, 1.7-89.4). Compared to siblings, survivors were at increased risk for grade 1-5 CHC (HR 2.1, 95% CI, 1.9-2.3) with similar HR across eras (HR1970s= 1.9, 95% CI, 1.6-2.2; HR1980s= 2.2, 95% CI, 1.9-2.6; HR1990s= 2.0, 95% CI, 1.7-2.4). The HR of severe, disabling, life-threatening and fatal CHC (grades 3-5) decreased in more recent eras (HR1970s= 4.7, 95% CI, 3.4-6.6; HR1980s= 4.4, 95% CI, 3.2-6.2; HR1990s= 2.9, 95% CI, 2.0-4.3). Conclusions: Survivors of infant neuroblastoma remain at increased risk for late mortality, SMN, and CHCs many years after diagnosis. However, the risk of grade 3-5 CHCs has declined in more recent eras, likely reflecting de-intensification of therapy.

Combined effect of radiotherapy and anthracyclines on risk of breast cancer among female childhood cancer survivors: A report from the Childhood Cancer Survivor Study (CCSS)

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Background: Breast cancer is a common late-effect for female childhood cancer survivors and chest radiotherapy is an established risk factor. Recent findings showed that treatment with anthracyclines also increases breast cancer risk. However, the risk from the combined effect of radiotherapy and anthracyclines is unknown. Methods: We conducted a matched case-control study of 271 subsequent breast cancer and 1044 controls nested within the CCSS - a North-American cohort of five-year survivors of childhood cancer, diagnosed from 1970-1986 and followed-up through 2016. Detailed treatment records were abstracted to estimate radiation dose (Gy) to the breast cancer location and ovaries and calculate cumulative chemotherapy doses (mg/m2). Multivariable conditional logistic regression was used to estimate Odds ratios (OR) and 95% confidence intervals (CI). Results: Breast cancer risk increased linearly with radiation dose to the breast (OR per 10Gy = 3.9, 95%CI:2.5-6.5) and decreased with increasing ovarian dose (p < 0.01). Adjusted for radiation dose, the highest quartile of dose (455+mg/m2) of anthracyclines was associated with a 3.8-fold increased risk of breast cancer (95%CI:1.8-8.2) compared to no anthracyclines. This risk increased with cumulative anthracycline dose (p-trend < 0.01) and was non-significantly higher for ER+ than ER- breast cancers. For a breast dose of 10+Gy, the OR was 19.1 (95%CI:7.6-48.0) with anthracyclines versus 9.6 (95%CI:4.4-20.7) without anthracyclines, compared to 0- < 1Gy breast dose and no anthracyclines (p-additive interaction = 0.04). Conclusions: The combination of anthracyclines and radiotherapy doses to the breast can markedly increase breast cancer risk compared to those who receive neither treatment. Our results can be used to inform risk management for childhood cancer patients treated in the past, as well as project potential breast cancer risk from current treatment protocols.