Site-specific patterns of early-stage cancer diagnosis during the COVID-19 pandemic

The COVID-19 pandemic caused widespread disruptions in cancer care. We hypothesized that the greatest disruptions in diagnosis occurred in screen-detected cancers. We identified patients (≥18 years of age) with newly diagnosed cancer from 2019 to 2020 in the US National Cancer Database and calculated the change in proportion of early-stage to late-stage cancers using a weighted linear regression. Disruptions in early-stage diagnosis were greater than in late-stage diagnosis (17% vs 12.5%). Melanoma demonstrated the greatest relative decrease in early-stage vs late-stage diagnosis (22.9% vs 9.2%), whereas the decrease was similar for pancreatic cancer. Compared with breast cancer, cervical, melanoma, prostate, colorectal, and lung cancers showed the greatest disruptions in early-stage diagnosis. Uninsured patients experienced greater disruptions than privately insured patients. Disruptions in cancer diagnosis in 2020 had a larger impact on early-stage disease, particularly screen-detected cancers. Our study supports emerging evidence that primary care visits may play a critical role in early melanoma detection.

Updated Analysis of Comparative Toxicity of Proton and Photon Radiation for Prostate Cancer

PURPOSE

Previous comparative effectiveness studies have not demonstrated a benefit of proton beam therapy (PBT) compared with intensity-modulated radiation therapy (IMRT) for prostate cancer. An updated comparison of GI and genitourinary (GU) toxicity is needed.

METHODS

We investigated the SEER-Medicare linked database, identifying patients with localized prostate cancer diagnosed from 2010 to 2017. Procedure and diagnosis codes indicative of treatment-related toxicity were identified. As a sensitivity analysis, we also identified toxicity based only on procedure codes. Patients who underwent IMRT and PBT were matched 2:1 on the basis of clinical and sociodemographic characteristics. We then compared GI and GU toxicity at 6, 12, and 24 months after treatment.

RESULTS

The final sample included 772 PBT patients matched to 1,544 IMRT patients. The frequency of GI toxicity for IMRT versus PBT was 3.5% versus 2.5% at 6 months (P = .18), 9.5% versus 10.2% at 12 months (P = .18), and 20.5% versus 23.4% at 24 months (P = .11). The frequency of only procedure codes indicative of GI toxicity for IMRT versus PBT was too low to be reported and not significantly different. The frequency of GU toxicity for IMRT versus PBT was 6.8% versus 5.7% (P = .30), 14.3% versus 12.2% (P = .13), and 28.2% versus 25.8% (P = .21) at 6, 12, and 24 months, respectively. When looking only at procedure codes, the frequency of GU toxicity for IMRT was 1.0% at 6 months, whereas it was too infrequent to report for PBT (P = .64). GU toxicity for IMRT versus PBT was 3.3% versus 2.1% (P = .10), and 8.7% versus 6.7% (P = .10) at 12 and 24 months, respectively.

CONCLUSION

In this observational study, there were no statistically significant differences between PBT and IMRT in terms of GI or GU toxicity.

Prognosis and risk of suicide after cancer diagnosis

INTRODUCTION

Suicide rates are elevated after cancer diagnosis. Existential distress caused by awareness of one's impending death is well-described in patients with cancer. The authors hypothesized that suicide risk is associated with cancer prognosis, and the impact of prognosis on suicide risk is greatest for populations with higher baseline suicide risk.

METHODS

The authors identified patients (≥16 years old) with newly diagnosed cancers from 2000 to 2019 in the Surveillance, Epidemiology, and End Results database, representing 27% of US cancers. Multiple primary-standardized mortality ratios (SMR) were used to estimate the relative risk of suicide within 6 months of diagnosis compared to the general US population, adjusted for age, sex, race, and year of follow-up. Suicide rates by 20 most common cancer sites were compared with respective 2-year overall survival rates (i.e., prognosis) using a weighted linear regression model.

RESULTS

Among 6,754,704 persons diagnosed with cancer, there were 1610 suicide deaths within 6 months of diagnosis, three times higher than the general population (SMR = 3.1; 95% confidence interval, 3.0-3.3). Suicide risk by cancer site was closely associated with overall prognosis (9.5%/percent survival deficit, R2  = 0.88, p < .0001). The association of prognosis with suicide risk became attenuated over time. For men, the risk of suicide increased by 2.8 suicide deaths per 100,000 person-years (p < .0001) versus 0.3 in women (p < .0001). The risk was also higher for persons ≥60 old and for the White (vs. Black) race.

CONCLUSIONS

Poorer prognosis was closely associated with suicide risk early after cancer diagnosis and had a greater effect on populations with higher baseline risks of suicide. This model highlights the need for enhanced psychiatric surveillance and continued research in this patient population.

MGMT promoter methylation in 1p19q-intact gliomas

OBJECTIVE

Standard-of-care for 1p19q-intact anaplastic gliomas is defined by the international randomized phase III CATNON trial, which found an overall survival (OS) benefit for adjuvant temozolomide (TMZ) when added to radiotherapy. Paradoxically, TMZ did not appear to benefit patients with IDH-wildtype gliomas, regardless of MGMT promoter status. The authors concluded that well-powered prospective study on the clinical efficacy of TMZ for patients with IDH-wildtype anaplastic gliomas (meeting criteria for glioblastoma) is warranted. Given that the prognostic and predictive role of MGMT status for grade 2-3 gliomas is unresolved, we determined the effect of MGMT status on OS in patients with 1p19q-intact gliomas in the National Cancer Database (NCDB).

METHODS

We queried the NCDB from 2018 to 2019 for patients with diffuse (grade 2) and anaplastic (grade 3) IDH-wildtype or -mutant astrocytomas who received chemotherapy with follow-up through 2022. The Kaplan-Meier method and Cox proportional hazards regressions models were used to determine the association of MGMT with OS.

RESULTS

We identified 1514 patients who were newly diagnosed with IDH-wildtype (n = 802, 33% methylated) or -mutant astrocytomas (n = 712, 48% methylated) and received chemotherapy during initial management. An unmethylated promoter was associated with poorer survival in patients with IDH-wildtype (3-year OS 34% [95%CI 29-39%] vs. 46% [95%CI 39-54%], p < .001, adjusted HR 1.53 [95%CI 1.24-1.89]) but not IDH-mutant astrocytomas (3-year OS 79% [95%CI 74-84%] vs. 80% [95%CI 75-86%], p =0 .81, HR 1.04 [95%CI 0.73-1.50]).

CONCLUSIONS

This ancillary analysis supports conclusions from the CATNON trial for adjuvant TMZ as standard-of-care for anaplastic astrocytomas (IDH-mutant and 1p19q-intact), irrespective of MGMT status. Determining the optimal strategy for diffuse gliomas that are IDH-wildtype will be particularly important. MGMT promoter methylation should be considered as a stratification factor in future clinical trials for these patients.

Influenza activity and regional mortality for non-small cell lung cancer

Lung cancer is the leading cause of cancer deaths in the United States and worldwide. While influenza illness is known to be particularly dangerous for frail and elderly patients, the relationship between influenza illness and outcomes in patients with cancer remains largely unknown. The Surveillance, Epidemiology, and End Results (SEER) database was queried to identify patients with non-small cell lung cancer (NSCLC) diagnosed between 2009 and 2015. Influenza-like illness (ILI) activity, provided by the Outpatient Influenza-like Illness Surveillance Network of the Center of Disease for Control and Prevention, was merged with the SEER dataset on the state-month level. Regional monthly mortality rates were compared during low versus high flu months in this ecological cohort study. 202,485 patients with NSCLC from 13 SEER-reporting states were included in the analysis. 53 of 1049 state-months (5.1%) had high flu activity. Monthly mortality rates during low and high flu months were 0.041 (95% CI 0.041-0.042) and 0.051 (95% CI 0.050-0.053), respectively (RR 1.24 [95% CI 1.21-1.27]). The association between ILI activity and mortality was observed at the individual state level and in all clinical and regional subgroups. Increased regional influenza activity is associated with higher mortality rates for patients with NSCLC. Vaccine-directed initiatives and increased awareness amongst providers will be necessary to address the growing but potentially preventable burden of influenza-related lung cancer deaths in the U.S.

MGMT Promoter Methylation Predicts Overall Survival after Chemotherapy for 1p/19q-Codeleted Gliomas

PURPOSE

While MGMT promoter methylation (mMGMT) is predictive of response to alkylating chemotherapy and guides treatment decisions in glioblastoma, its role in grade 2 and 3 glioma remains unclear. Recent data suggest that mMGMT is prognostic of progression-free survival in 1p/19q-codeleted oligodendrogliomas, but an effect on overall survival (OS) has not been demonstrated.

EXPERIMENTAL DESIGN

We identified patients with newly diagnosed 1p/19q-codeleted gliomas and known MGMT promoter status in the National Cancer Database from 2010 to 2019. Multivariable Cox proportional hazards regression modeling was used to assess the effect of mMGMT on OS after adjusting for age, sex, race, comorbidity, grade, extent of resection, chemotherapy, and radiotherapy.

RESULTS

We identified 1,297 eligible patients, 938 (72.3%) of whom received chemotherapy in their initial course of treatment. The MGMT promoter was methylated in 1,009 (77.8%) patients. Unmethylated MGMT (uMGMT) was associated with worse survival compared with mMGMT [70% {95% confidence interval (CI), 64%-77%} vs. 81% (95% CI, 78%-85%); P < 0.001; adjusted HR (aHR), 2.35 (95% CI, 1.77-3.14)]. uMGMT was associated with worse survival in patients who received chemotherapy [63% (95% CI, 55-73%) vs. 80% (95% CI, 76%-84%); P < 0.001; aHR, 2.61 (95% CI, 1.89-3.60)] but not in patients who did not receive chemotherapy [P = 0.38; HR, 1.31 (95% CI, 0.71-2.42)]. Similar results were observed regardless of World Health Organization grade and after single- or multiagent chemotherapy.

CONCLUSIONS

Our study demonstrates an association between mMGMT and OS in 1p/19q-codeleted gliomas. MGMT promoter status should be considered as a stratification factor in future clinical trials of 1p/19q-codeleted gliomas that use OS as an endpoint.

MGMT promoter methylation in 1p19q-intact gliomas

Objective

Standard-of-care for 1p19q-intact anaplastic gliomas is defined by the international randomized phase III CATNON trial, which found an overall survival (OS) benefit for adjuvant temozolomide (TMZ) when added to radiotherapy. Paradoxically, TMZ did not appear to benefit patients with IDH-wildtype gliomas, regardless of MGMT promoter status. The authors concluded that well-powered prospective study on the clinical efficacy of TMZ for patients with IDH-wildtype anaplastic gliomas (meeting criteria for glioblastoma) is warranted. Given that the prognostic and predictive role of MGMT status for grade 2-3 gliomas is unresolved, we determined the effect of MGMT status on OS in patients with 1p19q-intact gliomas in the National Cancer Database (NCDB).

Methods

We queried the NCDB from 2018-2019 for patients with IDH-wildtype or -mutant astrocytomas who received chemotherapy with follow-up through 2022. The Kaplan-Meier method and Cox proportional hazards regressions models were used to determine the association of MGMT with OS.

Results

We identified 1,514 patients who were newly diagnosed with IDH-wildtype (n = 802, 33% methylated) or - mutant astrocytomas (n = 712, 48% methylated) and received chemotherapy during initial management. An unmethylated promoter was associated with poorer survival in patients with IDH-wildtype (3-year OS 34% [95%CI 29-39%] vs. 46% [95%CI 39-54%], p < .001, adjusted HR 1.53 [95%CI 1.24-1.89]) but not IDH-mutant astrocytomas (3-year OS 79% [95%CI 74-84%] vs. 80% [95%CI 75-86%], p = .81, HR 1.04 [95%CI 0.73-1.50]).

Conclusions

This ancillary analysis supports adjuvant TMZ as standard-of-care for anaplastic astrocytomas (IDH-mutant and 1p19q-intact), irrespective of MGMT status. Determining the optimal strategy for diffuse gliomas that are IDH-wildtype will be particularly important. MGMT promoter methylation should be considered as a stratification factor in future clinical trials for these patients.

MGMT Promoter Methylation Predicts Survival in 1p19q-Codeleted Gliomas after Chemotherapy

PURPOSE/OBJECTIVE(S)

MGMT promoter methylation (mMGMT) is predictive of response to alkylating chemotherapy in glioblastomas and used to guide treatment decisions. However, the role of MGMT promoter status in low-grade and anaplastic gliomas remains unclear due to molecular heterogeneity and the lack of sufficiently large datasets. We recently found that MGMT promoter methylation predicts progression-free survival in 1p19q-codeleted gliomas after alkylating chemotherapy in a meta-analysis of three prospective cohorts. There were not enough deaths to determine the effect on overall survival. Here, we query a large national database to determine the association between MGMT promoter methylation and overall survival in patients with 1p19q-codeleted gliomas.

MATERIALS/METHODS

We identified all patients with newly diagnosed gliomas in the National Cancer Database (NCDB) from 2010-2016 with 1p19q-codeletion and information on MGMT promoter methylation status. The cohort was stratified based on receipt of chemotherapy. Multivariable Cox proportional hazards regression modeling was used to assess the effect of MGMT promoter methylation status on overall survival after adjusting for age, sex, race, co-morbidity, grade, extent of resection, chemotherapy, and radiotherapy.

RESULTS

We identified 530 eligible patients, 373 (70.4%) of whom received chemotherapy in their initial course of treatment. The MGMT promoter was methylated in 400 (75.5%) patients. For all patients, unmethylated MGMT (uMGMT) was associated with poorer survival compared to mMGMT (75% survival time [75%ST] 45 months vs. not reached, P = .003, adjusted hazard ratio [aHR] 2.36 [95% confidence interval (95% CI) 1.53-3.62]). uMGMT was associated with poorer survival in patients who received chemotherapy (75%ST 22 vs. 66 months, P<.001, aHR 2.55 [95% CI 1.60-4.06]) but not in patients who did not receive chemotherapy (75%ST 110 months vs. not reached, P = 0.7, HR 1.24 [95% CI 0.40-3.81]).

CONCLUSION

To our knowledge, this is the first study to demonstrate an association between overall survival and MGMT promoter status in 1p19q-codeleted gliomas. MGMT promoter status should be used as a stratification factor in future clinical trials of 1p19q-codeleted gliomas that use overall survival as an endpoint.

Risk of Squamous Cell Carcinoma of the Breast Following Postmastectomy Implant Reconstruction in Women With Breast Cancer and Carcinoma in Situ

This cohort study uses national surveillance data to describe the incidence and risk of squamous cell carcinoma after postmastectomy implant reconstruction in women with breast cancer.

Association of MGMT Promoter Methylation With Survival in Low-grade and Anaplastic Gliomas After Alkylating Chemotherapy

Importance

O6-methylguanine-DNA methyltransferase (MGMT [OMIM 156569]) promoter methylation (mMGMT) is predictive of response to alkylating chemotherapy for glioblastomas and is routinely used to guide treatment decisions. However, the utility of MGMT promoter status for low-grade and anaplastic gliomas remains unclear due to molecular heterogeneity and the lack of sufficiently large data sets.

Objective

To evaluate the association of mMGMT for low-grade and anaplastic gliomas with chemotherapy response.

Design, Setting, and Participants

This cohort study aggregated grade II and III primary glioma data from 3 prospective cohort studies with patient data collected from August 13, 1995, to August 3, 2022, comprising 411 patients: MSK-IMPACT, EORTC (European Organization of Research and Treatment of Cancer) 26951, and Columbia University. Statistical analysis was performed from April 2022 to January 2023.

Exposure

MGMT promoter methylation status.

Main Outcomes and Measures

Multivariable Cox proportional hazards regression modeling was used to assess the association of mMGMT status with progression-free survival (PFS) and overall survival (OS) after adjusting for age, sex, molecular class, grade, chemotherapy, and radiotherapy. Subgroups were stratified by treatment status and World Health Organization 2016 molecular classification.

Results

A total of 411 patients (mean [SD] age, 44.1 [14.5] years; 283 men [58%]) met the inclusion criteria, 288 of whom received alkylating chemotherapy. MGMT promoter methylation was observed in 42% of isocitrate dehydrogenase (IDH)-wild-type gliomas (56 of 135), 53% of IDH-mutant and non-codeleted gliomas (79 of 149), and 74% of IDH-mutant and 1p/19q-codeleted gliomas (94 of 127). Among patients who received chemotherapy, mMGMT was associated with improved PFS (median, 68 months [95% CI, 54-132 months] vs 30 months [95% CI, 15-54 months]; log-rank P < .001; adjusted hazard ratio [aHR] for unmethylated MGMT, 1.95 [95% CI, 1.39-2.75]; P < .001) and OS (median, 137 months [95% CI, 104 months to not reached] vs 61 months [95% CI, 47-97 months]; log-rank P < .001; aHR, 1.65 [95% CI, 1.11-2.46]; P = .01). After adjusting for clinical factors, MGMT promoter status was associated with chemotherapy response in IDH-wild-type gliomas (aHR for PFS, 2.15 [95% CI, 1.26-3.66]; P = .005; aHR for OS, 1.69 [95% CI, 0.98-2.91]; P = .06) and IDH-mutant and codeleted gliomas (aHR for PFS, 2.99 [95% CI, 1.44-6.21]; P = .003; aHR for OS, 4.21 [95% CI, 1.25-14.2]; P = .02), but not IDH-mutant and non-codeleted gliomas (aHR for PFS, 1.19 [95% CI, 0.67-2.12]; P = .56; aHR for OS, 1.07 [95% CI, 0.54-2.12]; P = .85). Among patients who did not receive chemotherapy, mMGMT status was not associated with PFS or OS.

Conclusions and Relevance

This study suggests that mMGMT is associated with response to alkylating chemotherapy for low-grade and anaplastic gliomas and may be considered as a stratification factor in future clinical trials of patients with IDH-wild-type and IDH-mutant and codeleted tumors.

Nationwide changes in radiation oncology travel and location of care before and during the COVID-19 pandemic

PURPOSE

Patients with cancer are particularly vulnerable to coronavirus disease (COVID). Transportation barriers made travel to obtain medical care more difficult during the pandemic. Whether these factors led to changes in the distance traveled for radiotherapy and the coordinated location of radiation treatment is unknown.

MATERIALS AND METHODS

We analyzed patients across 60 cancer sites in the National Cancer Database from 2018 to 2020. Demographic and clinical variables were analyzed for changes in distance traveled for radiotherapy. We designated the facilities in the 99th percentile or above in terms of the proportion of patients who traveled more than 200 miles as "destination facilities." We defined "coordinated care" as undergoing radiotherapy at the same facility where the cancer was diagnosed.

RESULTS

We evaluated 1,151,954 patients. There was a greater than 1% decrease in the proportion of patients treated in the Mid-Atlantic States. Mean distance traveled from place of residence to radiation treatment decreased from 28.6 to 25.9 miles, and the proportion traveling greater than 50 miles decreased from 7.7% to 7.1%. At "destination facilities," the proportion traveling more than 200 miles decreased from 29.3% in 2018 to 24% in 2020. In comparison, at the other hospitals, the proportion traveling more than 200 miles decreased from 1.07% to 0.97%. In 2020, residing in a rural area resulted in a lower odds of having coordinated care (multivariable odds ratio = 0.89; 95% confidence interval, 0.83-0.95).

CONCLUSION

The first year of the COVID pandemic measurably impacted the location of U.S. radiation therapy treatment.

National Patterns of Early Adoption of Magnetic Resonance Imaging-Guided Linear Accelerators in 2018 to 2019

Purpose

Adaptive magnetic resonance imaging-guided linear accelerators (aMRI-LINACs) are an emerging technology with the potential to improve radiation treatment for cancer through improved visualization and adaptive treatment. Given the competing forces of the increased cost, knowledge, and staff required for aMRI-LINAC therapy, it is unpredictable how rapidly and for whom aMRI-LINAC therapy is being adopted. Therefore, given that aMRI-LINAC therapy was granted approval from the Food and Drug Administration in late 2017, we evaluated the National Cancer Database (NCDB) to obtain a nationwide view of early aMRI-LINAC adoption in 2018 to 2019.

Methods and Materials

Forty-three disease sites were aggregated. A sample of patients who underwent intensity modulated radiation therapy (IMRT) from 2018 to 2019 were matched 1:1 by stage for the top 4 cancer sites. We then compared 9 characteristics of interest (age, % White [vs non-White], % residing in metro areas, % living in the greatest income quartile, % insured by Medicare, % uninsured or unknown insurance status, % treated at a comprehensive cancer center or academic center, % with no recorded Charlson-Deyo comorbidities, and % residing in an area with highest educational) between the 2 samples (aMRI-LINAC and matched IMRT).

Results

Only 171 patients were recorded as having been treated with aMRI-LINACs in the NCDB in 2018 to 2019. Fifty-six percent were male, 89% White, and 54% enrolled in Medicare. The most common sites of disease treated were lung (33 patients), pancreas (30 patients), prostate (29 patients), and breast (23 patients). There were no significant differences between aMRI-LINAC- and IMRT-matched patients except that patients with lung or breast cancer treated with aMRI-LINAC were significantly more likely to be treated at a comprehensive cancer center or academic center.

Conclusions

aMRI-LINAC adoption recorded in the NCDB after Food and Drug Administration approval was potentially underreported, slow, and attributed to academic sites of practice. Further longitudinal study will be needed to assess how practice patterns evolve with greater adoption.

A gamma ray spectrometer with Compton suppression on the HL-2A tokamak

A new broad-energy, high-resolution gamma ray spectrometer (GRS) with Compton suppression function has been developed recently in the HL-2A tokamak to obtain the gamma ray information in the energy range of 0.1-10 MeV. This is the first time to develop an anti-Compton GRS for a magnetic confinement fusion device. The anticoincidence detector consists of a large-volume high purity germanium (HPGe) crystal (Φ63 × 63 mm²) as the primary detector and eight trapezoidal bismuth germinate (BGO) scintillators (trapezoid crystal with 30 mm thickness) as the secondary detector. The anti-coincidence data processing is implemented by a digital-based data acquisition system with fast digitization and software signal processing technology. Using radioisotope gamma ray sources and Monte Carlo N-Particle code, the energy and efficiency of the spectrometer have been calibrated and quantitatively tested. The Compton continuum suppression factor reaches 4.2, and the energy resolution (Full Width at Half Maximum) of the 1.332 MeV full energy peak for ⁶⁰Co is 2.1 keV. Measurements of gamma ray spectra with Compton suppression using the spectrometer have been successfully performed during HL-2A discharges with different conditions. The performance of the spectrometer and the first experimental results are presented in this paper.

Risk of Anaplastic Large Cell Lymphoma Following Postmastectomy Implant Reconstruction in Women With Breast Cancer and Ductal Carcinoma in Situ

This cohort study examines the risk of anaplastic large cell lymphoma (ALCL) following postmastectomy implant reconstruction among US women with breast cancer and ductal carcinoma in situ (DCIS).

Prevalence of Estrogen Receptor Alpha (ESR1) Somatic Mutations in Breast Cancer

Estrogen receptor–positive breast tumors, which initially respond effectively to endocrine therapy, progress due to acquired endocrine therapy resistance, including genomic alterations in estrogen receptor alpha (ESR1). A recent study has suggested that there is a sufficient number of preexisting ESR1 mutations acting as an intrinsic resistance mechanism to warrant primary screening. We determined the incidence of de novo ESR1 mutations in hormone-positive treatment-naïve primary breast tumors using 12 publicly available international datasets in the cBioPortal. The prevalence of mutation was statistically significantly lower in treatment-naïve primary tumors (n = 6 of 3682, 0.16%) than in metastatic (n = 156 of 1089, 14.3%, 2-sided P < .001) or previously treated primary tumors (n = 11 of 92, 12.0%, 2-sided P < .001). Pathogenic ESR1 mutations are a common mechanism of acquired but not intrinsic resistance to endocrine therapy and may not warrant universal testing of primary breast cancer populations.

Smurf2 inhibition enhances chemotherapy and radiation sensitivity in non-small-cell lung cancer

Lung cancer has been the most common cancer worldwide for several decades. The outcomes of patients with locally advanced lung cancer remain dismal, and only a minority of patients survive more than 5 years. However, tumor therapeutic resistance mechanisms are poorly studied. Identification of therapeutic resistance pathways in lung cancer in order to increase the sensitivity of lung tumor cells to therapeutic agents is a crucial but challenging need. To identify novel genes that modulate the response to platinum-based therapy, we performed a genome-wide high-throughput ribonucleic acid interference (RNAi) screen via transfection of human lung cancer (PC9) cells with a viral short hairpin RNA (shRNA) library. We further validated a potential target via 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and clonogenic survival assays on PC9 and A549 lung tumor cells transfected with small interfering RNAs (siRNAs) to successfully downregulate protein expression and then treated with increasing doses of cisplatin or X-ray radiation. We determined protein expression by immunohistochemistry (IHC) after chemoradiotherapy and analyzed gene expression-based survival outcomes in two cohorts of human non-small-cell lung cancer (NSCLC) patients. The screen identified several targets involved in epithelial-to-mesenchymal transition (EMT), including Smurf1, Smurf2, YAP1, and CEBPZ, and glycolytic pathway proteins, including PFKFB3. Furthermore, we found that the small molecule proteasome inhibitor bortezomib significantly downregulated Smurf2 in lung cancer cells. The addition of bortezomib in combination with cisplatin and radiation therapy in PC9 and A549 cells led to an increase in deoxyribonucleic acid (DNA) double-strand breaks with increased numbers of γ-H2AX-positive cells and upregulation of apoptosis. Finally, we found that Smurf2 protein expression was upregulated in situ after treatment with cisplatin and radiation therapy in a relevant cohort of patients with stage III NSCLC. Additionally, Smurf2 gene expression was the strongest predictor of survival in patients with squamous NSCLC after chemotherapy or chemoradiotherapy. We successfully identified and validated Smurf2 as both a common modulator of resistance and an actionable target in lung cancer. These results suggest the urgent need to investigate clinical Smurf2 inhibition via bortezomib in combination with cisplatin and radiation for patients with locally advanced NSCLC.

Risk of corticosteroid treatment and hospitalization after checkpoint inhibitor and radiation therapy in patients with cancer

BACKGROUND

Immune checkpoint inhibitors (ICIs) are potent new cancer therapies but can cause serious immune-related adverse events. ICIs have contributed significantly to improved survival and thereby provide more opportunity for the development of local disease symptomatology requiring palliative radiation. Radiation therapy (RT) has also recently shown benefit in the oligometastatic setting. Data on the interaction and safety of concurrent ICIs and RT are limited.

METHODS

In this retrospective cohort study using a large medical claims database from 2010 to 2017, the need for corticosteroid therapy and the risk of hospitalization within 180 days of treatment with an ICI were determined for patients with a diagnosis of malignant melanoma or lung cancer. Patients were stratified by the use of RT within the 30 days before and after ICI therapy.

RESULTS

In all, 2020 patients (218 with RT and 1802 without RT) met the inclusion criteria for prednisone analysis, whereas 3519 patients (361 with RT and 3158 without RT) met the inclusion criteria for all other analyses. In a univariable analysis, RT was not associated with the need for prednisone (relative risk [RR], 1.2; 95% confidence interval [CI], 0.8-1.9) or methylprednisolone (RR, 1.1; 95% CI, 0.7-2.0). When the end point was hospitalization, RT was significantly associated with hospitalization after ICI therapy for certain cancer/drug combinations (RR for lung cancer/programmed death 1 receptor inhibitors, 1.4; 95% CI, 1.2-1.6; P < .001; RR for melanoma/ipilimumab, 2.0; 95% CI, 1.0-3.5; P = .03).

CONCLUSIONS

In patients treated with ICIs, receiving RT was not associated with a higher risk of requiring corticosteroid therapy in comparison with not receiving RT. However, RT was associated with a higher risk of hospitalization, although this finding may be a result of differences in the underlying patient illness severity or oncologic disease burden at the baseline.

LAY SUMMARY

Data on the interaction of immunotherapy (immune checkpoint inhibitors) and radiation therapy and the safety of combining them are limited. Using a large database, this study has found that patients treated concurrently with immune checkpoint inhibitors and radiation therapy are not at increased risk for requiring corticosteroid therapy (which is used as a proxy for immune-related adverse events). However, concurrent therapy is associated with a higher risk of hospitalization, although this finding may be due to differences in the underlying patient illness severity (sicker patients may require both immunotherapy and radiation therapy).

Time resolved absolute extreme ultraviolet radiation measurement on the ENN XuanLong-50 spherical tokamak

A plasma radiation measurement system for a wide spectral range, based on compact Absolute eXtreme UltraViolet (AXUV) silicon photodiodes, has been implemented on the newly constructed ENN XuanLong-50 (EXL-50) spherical tokamak. The system consists of two 16-channel AXUV16ELG arrays and one AXUV63HS1 single-cell detector mounted on ceramic sockets. The two arrays, facing toward the EXL-50 slim central post from two locations inside a top and a side ConFlat 400 port, have 32 view chords covering the interested plasma region in a poloidal cross section at toroidal 330°. The single-cell detector, seated on a retractable feedthrough, could be arranged flexibly with the help of an ultra-high vacuum compatible gate valve. The design details together with considerations on the EXL-50 specific engineering realities and physics requirements are described. Preliminary results from the EXL-50 2020 experimental campaign are presented.

Efficacy and cost of high-frequency IGRT in elderly stage III non-small-cell lung cancer patients

Background

High-frequency image-guided radiotherapy (hfIGRT) is ubiquitous but its benefits are unproven. We examined the cost effectiveness of hfIGRT in stage III non-small-cell lung cancer (NSCLC).

Methods

We selected stage III NSCLC patients ≥66 years old who received definitive radiation therapy from the Surveillance, Epidemiology, and End-Results-Medicare database. Patients were stratified by use of hfIGRT using Medicare claims. Predictors for hfIGRT were calculated using a logistic model. The impact of hfIGRT on lung toxicity free survival (LTFS), esophageal toxicity free survival (ETFS), cancer-specific survival (CSS), overall survival (OS), and cost of treatment was calculated using Cox regressions, propensity score matching, and bootstrap methods.

Results

Of the 4,430 patients in our cohort, 963 (22%) received hfIGRT and 3,468 (78%) did not. By 2011, 49% of patients were receiving hfIGRT. Predictors of hfIGRT use included treatment with intensity-modulated radiotherapy (IMRT) (OR = 7.5, p < 0.01), recent diagnosis (OR = 51 in 2011 versus 2006, p < 0.01), and residence in regions where the Medicare intermediary allowed IMRT (OR = 1.50, p < 0.01). hfIGRT had no impact on LTFS (HR 0.97; 95% CI 0.86–1.09), ETFS (HR 1.05; 95% CI 0.93–1.18), CSS (HR 0.94; 95% CI 0.84–1.04), or OS (HR 0.95; 95% CI 0.87–1.04). Mean radiotherapy and total medical costs six months after diagnosis were $17,330 versus $15,024 (p < 0.01) and $71,569 versus $69,693 (p = 0.49), respectively.

Conclusion

hfIGRT did not affect clinical outcomes in elderly patients with stage III NSCLC but did increase radiation cost. hfIGRT deserves further scrutiny through a randomized controlled trial.

Toroidal soft x-ray array on the EXL-50 spherical tokamak

A toroidal soft x-ray array system for spectrum and intensity measurements on the EXL-50 spherical tokamak is described. Silicon drift detectors and digital multichannel analyzers are adopted for all 21 channels of the array, and an average energy resolution of 147 eV at 5.89 keV has been achieved at count rates over 500 kcps. In total, 20 channels of the array are symmetrically observed in both co- and counter-current directions on the EXL-50 mid-plane with a spatial resolution of around 10 cm, and the remaining one serves as a background reference channel. Tungsten emissions from tungsten coating of the limiters on the central post are observed. The influence of hard x rays on measured soft x-ray spectra and system operation is discussed.

Tangential hard x-ray diagnostic array on the EXL-50 spherical tokamak

A tangential hard x-ray (HXR) diagnostic on the newly constructed ENN XuanLong-50 (EXL-50) spherical tokamak for fast electron emission studies is presented. The HXR detection system consists of a symmetrical CdZnTe semiconductor detector array with a spectral sensitivity range of 20-300 keV. 25 channels have been designed on the 270° horizontal vacuum port with 12 sight lines to observe the forward emission, 12 sight lines to observe the backward emission of fast electrons, and 1 for viewing the central. Currently, ten channels have been in operation in the EXL-50 experiments. The systems are designed to measure the x-ray spectra for the estimation of fast electron temperature and electron velocity distribution in the EXL-50 experiment, which will be useful for understanding the dynamics of fast electrons generated by electron cyclotron resonance heating, for plasma instability and transport studies and for the analysis of plasma heating efficiency.

Outcomes for localized treatment of large cell neuroendocrine carcinoma of the lung in the United States

Background

Treatment paradigms for large cell neuroendocrine carcinoma (LCNEC) of the lung are based largely upon small retrospective studies and smaller prospective trials. It is unclear if these tumors behave like non-small cell lung cancer (NSCLC) or small cell lung cancer (SCLC). Data are lacking with regard to the role of radiotherapy (RT). U. S. guidelines recommend that LCNEC be treated as a NSCLC. We sought to perform a cross-sectional study of LCNEC cases to understand treatment paradigms and outcomes in this disease.

Methods

The Surveillance, Epidemiology and End Results database was queried for cases of stage I-III pulmonary LCNEC diagnosed 2004-2013. Treatment groups were defined as no surgery, RT alone, surgery alone, and surgery + RT. The Cox-proportional hazards regression model was used to compare overall survival and cause-specific survival (OS/CSS), stratified by AJCC 6th Staging. Factors that were significant on univariable analysis were included in multivariable analysis.

Results

We identified 1,523 cases of LCNEC, with 748, 177, and 598 cases of stage I, II, and III disease, respectively. In stage I and II disease, RT was associated with improved survival for non-surgical patients, but not for those who underwent surgery. In stage I disease, the adjusted hazard ratios for OS for RT alone, surgery, and surgery + RT were 0.39, 0.21, and 0.22, respectively (P<0.001). In stage II disease, the adjusted hazard ratios for RT alone, surgery, and surgery + RT were 0.51 (P=0.15), 0.39 (P=0.004), and 0.38 (P=0.01), respectively. For patients with stage III disease, RT was associated with improved survival in surgical and non-surgical patients. The adjusted hazard ratios for RT alone, surgery, and surgery + RT were 0.49, 0.43, and 0.36, respectively (P<0.001).

Conclusions

Our findings indicate that non-metastatic LCNEC may be treated as a NSCLC with respect to RT. Prospective studies are necessary to increase our understanding of optimal treatment regimens.

Increased rates of immunosuppressive treatment and hospitalization after checkpoint inhibitor therapy in cancer patients with autoimmune disease

BACKGROUND

Immune checkpoint inhibitors (ICIs) are important new therapeutic options for the treatment of malignancy. Existing data on the relative safety of ICI treatment in patients with pre-existing autoimmune disease (AID) are limited.

METHODS

In this retrospective study utilizing an oncology medical claims database, we determined the rates of treatment with immunosuppressive agents and hospitalization within 180 days of treatment with ICIs (pembrolizumab, nivolumab, and ipilimumab) in patients both with and without AID. Patients had diagnoses of either malignant melanoma or lung cancer. Immunosuppressive agents evaluated included oral prednisone and intravenous methylprednisolone.

RESULTS

124 cancer patients with AID and 1896 cancer patients without AID met inclusion criteria for oral prednisone analysis, while 284 patients with AID and 3230 patients without AID met inclusion criteria for all other analyzes. Following treatment with PD-1 inhibitors, rates of treatment with both oral prednisone and intravenous methylprednisolone within 180 days of ICI treatment were significantly increased in the AID group relative to the control group (oral prednisone: 16.7% treatment in AID vs 8.3% in non-AID, p=0.0048; intravenous methylprednisolone: 8.4% treatment in AID vs 3.7% in non-AID, p=0.0012). Rates of hospitalization were significantly increased in melanoma patients with AID relative to melanoma patients without AID following treatment with PD-1 inhibitors (24.1% in AID vs 5.8% in non-AID, p<0.0001).

CONCLUSION

Cancer patients with AID have higher rates of hospitalization and treatment with immunosuppressive agents following treatment with ICI therapy compared with patients with no AID. This suggests that patients with AID may have increased toxicity risk while being treated with checkpoint inhibitor therapy. Further prospective clinical trials are needed to determine safety.

Extent of resection, molecular signature, and survival in 1p19q-codeleted gliomas

OBJECTIVE

Genomic analysis in neurooncology has underscored the importance of understanding the patterns of survival in different molecular subtypes within gliomas and their responses to treatment. In particular, diffuse gliomas are now principally characterized by their mutation status (IDH1 and 1p/19q codeletion), yet there remains a paucity of information regarding the prognostic value of molecular markers and extent of resection (EOR) on survival. Furthermore, given the modern emphasis on molecular rather than histological diagnosis, it is important to examine the effect of maximal resection on survival in all gliomas with 1p/q19 codeletions, as these will now be classified as oligodendrogliomas under the new WHO guidelines. The objectives of the present study were twofold: 1) to assess the association between EOR and survival for patients with oligodendrogliomas in the National Cancer Database (NCDB), which includes information on mutation status, and 2) to demonstrate the same effect for all patients with 1p/19q codeleted gliomas in the NCDB.

METHODS

The NCDB was queried for all cases of oligodendroglioma between 2004 and 2014, with follow-up dates through 2016. The authors found 2514 cases of histologically confirmed oligodendrogliomas for the final analysis of the effect of EOR on survival. Upon further query, 1067 1p/19q-codeleted tumors were identified in the NCDB. Patients who received subtotal resection (STR) or gross-total resection (GTR) were compared to those who received no tumor debulking surgery. Univariable and multivariable analyses of both overall survival and cause-specific survival were performed.

RESULTS

EOR was associated with increased overall survival for both histologically confirmed oligodendrogliomas and all 1p/19q-codeleted-defined tumors (p < 0.001 and p = 0.002, respectively). Tumor grade, location, and size covaried predictably with EOR. When evaluating tumors by each classification system for predictors of overall survival, facility setting, age, comorbidity index, grade, location, chemotherapy, and radiation therapy were all shown to be significantly associated with overall survival. STR and GTR were independent predictors of improved survival in historically classified oligodendrogliomas (HR 0.83, p = 0.18; HR 0.69, p = 0.01, respectively) and in 1p/19q-codeleted tumors (HR 0.49, p < 0.01; HR 0.43, p < 0.01, respectively).

CONCLUSIONS

By using the NCDB, the authors have demonstrated a side-by-side comparison of the survival benefits of greater EOR in 1p/19q-codeleted gliomas.

Focused ultrasound induced-blood-brain barrier opening in mouse brain receiving radiosurgery dose of radiation enhances local delivery of systemic therapy

OBJECTIVE

Investigate the temporal effects of focused ultrasound (FUS)-induced blood-brain barrier (BBB) opening in post-radiotherapy mouse brains.

METHODS AND MATERIALS

C57B6 mice without tumors were used to simulate the scenario after gross total resection (GTR) of brain tumor. Radiation dose of 6 Gy x 5 was delivered to one-hemisphere of the mouse brain. FUS-induced BBB-opening was delivered to the irradiated and non-irradiated brain and was confirmed with MRI. Dynamic MRI was performed to evaluate blood vessel permeability. Two time points were selected: acute (2 days after radiation) and chronic (31 days after radiation).

RESULTS

BBB opening was achieved after FUS in the irradiated field as compared to the contralateral non-irradiated brain without any decrease in permeability. In the acute group, a trend for higher gadolinium concentration was observed in radiated field.

CONCLUSION

Localized BBB-opening can be successfully achieved without loss of efficacy by FUS as early as 2 days after radiotherapy.

ADVANCES IN KNOWLEDGE

Adjuvant radiation after GTR is commonly used for brain tumors. Focused ultrasound facilitated BBB-opening can be achieved without loss of efficacy in the post-irradiated brain as early as 2 days after radiation therapy. This allows for further studies on early application of FUS-mediated BBB-opening.

Radiation-Induced Lipid Peroxidation Triggers Ferroptosis and Synergizes with Ferroptosis Inducers

Although radiation is widely used to treat cancers, resistance mechanisms often develop and involve activation of DNA repair and inhibition of apoptosis. Therefore, compounds that sensitize cancer cells to radiation via alternative cell death pathways are valuable. We report here that ferroptosis, a form of nonapoptotic cell death driven by lipid peroxidation, is partly responsible for radiation-induced cancer cell death. Moreover, we found that small molecules activating ferroptosis through system xc- inhibition or GPX4 inhibition synergize with radiation to induce ferroptosis in several cancer types by enhancing cytoplasmic lipid peroxidation but not increasing DNA damage or caspase activation. Ferroptosis inducers synergized with cytoplasmic irradiation, but not nuclear irradiation. Finally, administration of ferroptosis inducers enhanced the antitumor effect of radiation in a murine xenograft model and in human patient-derived models of lung adenocarcinoma and glioma. These results suggest that ferroptosis inducers may be effective radiosensitizers that can expand the efficacy and range of indications for radiation therapy.

Surgery plus adjuvant radiotherapy for primary central nervous system lymphoma

Objective: Recent studies of primary central nervous system lymphoma (PCNSL) have found a positive association between cytoreductive surgery and survival, challenging the traditional notion that surgery is not beneficial and potentially harmful. However, no studies have examined the potential added benefits of adjuvant treatment in the post-operative setting. Here, we investigate survival in PCNSL patients treated with surgery plus radiation therapy (RT).Methods: The Surveillance, Epidemiology, and End-Results Program was used to identify patients with PCNSL from 1995-2013. We retrospectively analyzed the relationship between treatment, prognostic factors, and survival using case-control design. Treatment categories were compared to biopsy alone.Results: We identified 5417 cases. Median survival times for biopsy alone (n = 1824, 34%), biopsy + RT (n = 1460, 27%), surgery alone (n = 1222, 27%), and surgery + RT (n = 911, 17%) were 7, 8, 20, and 27 months, respectively. On multivariable analysis, surgery + RT was associated with improved survival over surgery alone (hazard ratio [HR] = 0.58 [95% confidence interval = 0.53-0.64] vs. HR = 0.71 [0.65-0.77]). Adjuvant RT was associated with improved survival, regardless of the extent of resection. HR's for subtotal resection, gross-total resection, subtotal resection + RT, and gross-total resection + RT were 0.77 (0.66-0.89), 0.66 (0.57-0.76), 0.62 (0.52-0.72), and 0.54 (0.46-0.63), respectively. Survival improved after adjuvant RT in patients under and over 60 years old. All findings were confirmed by multivariable analysis of cause-specific survival.Conclusion: Adjuvant RT was associated with improved survival in PCNSL patients who underwent surgery. Although these data are hypothesis-generating, additional information on neurotoxicity, dosing, and concurrent chemotherapy will be necessary to validate these findings. Cytoreductive surgery for PCNSL is common in the general population, and more studies are needed to assess optimal treatment in the post-operative setting.

Clear Cell Adenocarcinoma of the Urinary Bladder Is a Glycogen-Rich Tumor with Poorer Prognosis

Clear cell adenocarcinoma (CCA) is a rare variant of urinary bladder carcinoma with a glycogen-rich phenotype and unknown prognosis. Using the National Cancer Institute's surveillance, epidemiology, and end results (SEER) program database, we documented recent trends in incidence, mortality, demographical characteristics, and survival on this rare subtype of urinary bladder cancer. The overall age-adjusted incidence and mortality of CCA was 0.087 (95% confidence interval (CI): 0.069-0.107) and 0.064 (95% CI: 0.049-0.081) respectively per million population. In comparison to non-CCAs, CCAs were more commonly associated with younger age (<60 years old, p = 0.005), female (p < 0.001), black ethnicity (p = 0.001), grade III (p < 0.001), and higher AJCC 6th staging (p < 0.001). In addition, CCA patients more frequently received complete cystectomy (p < 0.001) and beam radiation (p < 0.001) than non-CCA patients. Our study showed a poorer prognosis of CCAs compared to all other carcinomas of the urinary bladder (p < 0.001), accounted for by higher tumor staging of CCA cases. This study adds to the growing evidence that glycogen-rich cancers may have unique characteristics affecting tumor aggressiveness and patient prognosis. Additional mechanistic studies are needed to assess whether it's the excess glycogen that contributes to the higher stage at diagnosis.

Extent of resection and survival for oligodendroglioma: a U.S. population-based study

BACKGROUND

National guidelines recommend maximal safe resection of low-grade and high-grade oligodendrogliomas. However, there is no level 1 evidence to support these guidelines, and recent retrospective studies on the topic have yielded mixed results.

OBJECTIVE

To assess the association between extent of resection (EOR) and survival for oligodendrogliomas in the general U.S.

POPULATION

METHODS

Cases diagnosed between 2004 and 2013 were selected from the Surveillance, Epidemiology, and End-Results (SEER) Program and retrospectively analyzed for treatment, prognostic factors, and survival times. Cases that did not undergo tumor de-bulking surgery (e.g. no surgery or biopsy alone) were compared to subtotal resection (resection) and gross-total resection (GTR). The primary end-points were overall survival (OS) and cause-specific survival (CSS). An external validation cohort with 1p/19q-codeleted tumors was creating using the TCGA and GSE16011 datasets.

RESULTS

3135 Cases were included in the final analysis. The 75% survival time (75ST) and 5-year survival rates were 47 months and 70.8%, respectively. Subtotal resection (STR, 75ST = 50 months) and GTR (75ST = 61 months) were associated with improved survival times compared to cases that did not undergo surgical debulking (75ST = 20 months, P < 0.001 for both), with reduced hazard ratios (HRs) after controlling for other factors (HR 0.81 [0.68-0.97] and HR 0.65 [0.54-0.79], respectively). GTR was associated with improved OS in both low-grade and anaplastic oligodendroglioma subgroups (HR 0.74 [0.58-0.95], HR 0.60 [0.44-0.82], respectively) while STR fell short of significance in the subgroup analysis. All findings were corroborated by multivariable analysis of CSS and externally validated in a cohort of patients with 1p19q-codeleted tumors.

CONCLUSION

Greater EOR is associated with improved survival in oligodendrogliomas. Our findings in this U.S. population-based cohort support national guidelines.

Large-Cell Neuroendocrine Carcinoma of the Lung: A Population-Based Study

INTRODUCTION

Large-cell neuroendocrine carcinoma (LCNEC) accounts for approximately 3% of lung malignancies. There are limited data on the epidemiology and best treatment practices for this malignancy. This study aimed to be the largest cohort with the most up-to-date analysis of the epidemiology of LCNEC.

PATIENTS AND METHODS

The Surveillance, Epidemiology, and End Results (SEER) database was queried to identify cases of LCNEC diagnosed from 2010 through 2015, reflecting years the American Joint Committee on Cancer 7th edition staging system was in use. Using these data, we compared the epidemiology, demographics, clinical characteristics, and survival times of LCNEC with small-cell lung carcinoma (SCLC) and non-SCLC (NSCLC). Trends in incidence and mortality were recorded from 2004 to 2015.

RESULTS

A total of 195,148 cases of lung cancer, including 1681 (0.9%) cases of LCNEC, were analyzed. LCNEC was more common among male subjects, and disease usually presented at stage IV (55%). Brain metastasis occurred more frequently in LCNEC (19.2%) than SCLC (16.7%, P < .001) or NSCLC (13%, P < .001). Incidence increased by 0.011 people per 100,000 per year, primarily of stage IV disease. Annual mortality from LCNEC doubled over the time period studied. Survival in patients with stage I-III LCNEC mirrored survival trends of patients with NSCLC, whereas stage IV LCNEC behaved similarly to SCLC.

CONCLUSION

LCNEC generally presents at more advanced stages than NSCLC but earlier than SCLC. Stage I-III LCNEC behaves similarly to NSCLC, whereas stage IV is more akin to SCLC. LCNEC incidence is increasing. Despite this, it remains poorly studied and did not demonstrate an improved prognosis in our cohort.

Frameless Stereotactic Radiosurgery on the Gamma Knife Icon: Early Experience From 100 Patients

BACKGROUND

The Gamma Knife (GK) Icon (Elekta AB) uses a cone-beam computed tomography (CBCT) scanner and an infrared camera system to support the delivery of frameless stereotactic radiosurgery (SRS). There are limited data on patients treated with frameless GK radiosurgery (GKRS).

OBJECTIVE

To describe the early experience, process, technical details, and short-term outcomes with frameless GKRS at our institution.

METHODS

We reviewed our patient selection and described the workflow in detail, including image acquisition, treatment planning, mask-based immobilization, stereotactic CBCT localization, registration, treatment, and intrafraction monitoring. Because of the short interval of follow-up, we provide crude rates of local control.

RESULTS

Data from 100 patients are reported. Median age is 67 yr old. 56 patients were treated definitively, 21 postoperatively, and 23 had salvage GKRS for recurrence after surgery. Forty-two patients had brain metastases, 26 meningiomas, 16 vestibular schwannomas, 9 high-grade gliomas, and 7 other histologies. Median doses to metastases were 20 Gy in 1 fraction (range: 14-21), 24 Gy in 3 fractions (range: 19.5-27), and 25 Gy in 5 fractions (range: 25-30 Gy). Thirteen patients underwent repeat SRS to the same area. Median treatment time was 17.7 min (range: 5.8-61.7). We found an improvement in our workflow and a greater number of patients eligible for GKRS because of the ability to fractionate treatments.

CONCLUSION

We report a large cohort of consecutive patients treated with frameless GKRS. We look forward to studies with longer follow-up to provide valuable data on clinical outcomes and to further our understanding of the radiobiology of hypofractionation in the brain.

Performance of the cone beam computed tomography-based patient positioning system on the Gamma Knife Icon™

PURPOSE

Cone beam computed tomography (CBCT) imaging has been implemented on the Leksell Gamma Knife^® Icon™ for assessing patient positioning in mask-based Gamma Knife radiosurgery. The purpose of this study was to evaluate the performance of the CBCT-based patient positioning system as a tool for frameless Gamma Knife radiosurgery.

METHODS

Daily quality assurance (QA) CBCT precision test results from a 12-month period were analyzed for the geometric accuracy and the stability of the imager. The performance of the image acquisition module and the image registration algorithm was evaluated using an anthropomorphic head phantom (CIRS Inc., Norfolk, VA) and a XYZR axis manual positioning stage (TOAUTO Inc., Guangdong, China). The head phantom was fixed on a mask adaptor and manually translated in the X, Y, Z directions or rotated around the X, Y, Z axes in the range of ±10 mm or ±10º. A CBCT scan was performed after each manual position setup followed by an image registration to the reference scan. To assess the overall setup uncertainties in fractionated treatment, two cylindrical Presage phantoms (Heuris Inc., Skillman, NJ) of 15 cm diameter and 10 cm height were irradiated with identical prescription dose and shot placement following standard mask-based treatment workflow according to two different fraction schedules: a single fraction treatment of 7.5 Gy and a 5-fraction treatment with 1.5 Gy per fraction.

RESULTS

The averaged vector deviations of the four marks from their preset values are 0.087, 0.085, 0.095, and 0.079 mm from the 212 daily QA tests. The averaged displacements in the X, Y, Z coordinates and the pitch, yaw, roll angles from the image registration tests are 0.23, 0.27, 0.14, 0.32º, 0.19º, 0.31º from the manual setup. The corresponding maximum differences are 0.41, 0.33, 0.29 mm, 0.45º, 0.31º, and 0.43º, respectively. Compared to the treatment plan using the 2% & 1 mm criteria, the averaged 2D Gamma passing rate is 98.25% for the measured dose distribution from the Presage phantom with 1-fraction irradiation and 95.12% for the 5-fraction irradiation. The averaged Gamma passing rates are 99.53% and 98.16% for the 1-fraction and 5-fraction irradiations using the 2% & 2 mm criteria.

CONCLUSIONS

The CBCT imager and the image registration algorithm can reproduce phantom position with <0.5 mm/0.5º uncertainty. A systematic contribution from the interfraction phantom repositioning procedure was observed in the Gamma analysis over the irradiated volumes of two end-to-end test phantoms.

Spinal location is prognostic of survival for solitary-fibrous tumor/hemangiopericytoma of the central nervous system

BACKGROUND

Prior studies have highlighted infratentorial tumor location as a prognostic factor for solitary fibrous tumor (SFT) and hemangiopericytoma (HPC) of the central nervous system (CNS), and spinal location is considered a positive prognostic factor for other tumors of the CNS. While SFT/HPC of the CNS is known to frequently arise from the spinal meninges, there are no case series that report outcomes for spinally located CNS tumors, and their prognosis in relation to intracranial and other CNS-located tumors is unknown.

OBJECTIVE

To investigate outcomes for patients with SFT/HPC of the spinal meninges.

METHODS

The Surveillance, Epidemiology, and End-Results Program was used to identify patients with SFT/HPC within the CNS from 1993-2015. We retrospectively analyzed the relationship between tumor location (spinal vs. Brain and other CNS) and survival.

RESULTS

We identified 551 cases of CNS SFT/HPC, 64 (11.6%) of which were primary tumors of the spinal meninges. Spinal tumors were more likely than brain and other CNS tumors to be SFT vs. HPC (37.5 vs. 12%, p < 0.001), benign (42.2 vs. 20.3%, p < 0.001), and less than 5 cm (53.1 vs. 35.7%, p < 0.001). The 10-year survival rates for spinal and brain/other CNS tumors were 85 and 58%, respectively. Median survival time was significantly longer for spinal tumors (median survival not reached vs. 138 months, p = 0.03, HR = 0.41 [95% CI 0.18-0.94]). On multivariable analysis, spinal tumor location was associated with improved survival over tumors located in the brain and other CNS (HR = 0.36 [95% CI 0.15-0.89], p = 0.03).

CONCLUSION

Spinal tumor location is associated with improved survival in patients with SFT/HPC of the CNS. Larger institutional studies are necessary to characterize the relationship between tumor location and other relevant factors such as presentation and amenability to gross-total resection and adjuvant radiotherapy. Future studies exploring optimal management of spinally located tumors are also needed.

Natural history, clinical course and predictors of interval time from initial diagnosis to development of subsequent NSCLC brain metastases

PURPOSE

Non-small cell lung cancer (NSCLC) brain metastases are associated with substantial morbidity and mortality. During recent years, accompanying dramatic improvements in systemic disease control, NSCLC brain metastases have emerged as an increasingly relevant clinical problem. However, optimal surveillance practices remain poorly defined. This purpose of this study was to further characterize the natural history, clinical course and risk factors associated with earlier development of subsequent NSCLC brain metastases to better inform clinical practice and help guide survivorship care.

METHODS

We retrospectively reviewed all institutional NSCLC brain metastasis cases treated with radiotherapy between 1997 and 2015. Exclusion criteria included presence of brain metastases at initial NSCLC diagnosis and incomplete staging information. Interval time to brain metastases and subsequent survival were characterized using Kaplan-Meier and multivariate Cox regression analyses.

RESULTS

Among 105 patients within this cohort, median interval time to development of brain metastases was 16 months. Median interval times were 29, 19, 16 and 13 months for Stage I-IV patients, respectively (P = 0.016). Additional independent predictors for earlier development of NSCLC brain metastases included non-adenocarcinomatous histopathology (HR 3.036, P < 0.001), no prior surgical resection (HR 1.609, P = 0.036) and no prior systemic therapy (HR 3.560, P = 0.004). Median survival following intracranial progression was 16 months. Delayed development of brain metastases was associated with better prognosis (HR 0.970, P < 0.001) but not survival following intracranial disease onset.

CONCLUSIONS

Collectively, our results provide valuable insights into the natural history of NSCLC brain metastases. NSCLC stage, histology, prior surgical resection and prior systemic therapy emerged as independent predictors for interval time to brain metastases.

Impact of estrogen monotherapy on survival in women with stage III-IV non-small cell lung cancer

OBJECTIVES

Women with lung cancer have better survival than men. The reasons are unknown, but estrogen is hypothesized to improve survival. Our objective was to examine the association between estrogen monotherapy and cancer-specific and overall survival in elderly women with non-small cell lung cancer (NSCLC).

MATERIALS AND METHODS

We used the SEER-Medicare database to identify women ≥65 years old who were diagnosed with stage III or IV NSCLC. Estrogen monotherapy (EM) was defined as at least one estrogen claim without any progesterone claims 6 months prior to diagnosis. To assess cancer-specific survival and overall survival, we used Kaplan-Meier and multivariate Cox modeling with propensity score adjustments. As an exploratory analysis, we also examined the effect of combined estrogen and progesterone hormonal therapy on survival using Cox modeling.

RESULTS

We identified 6958 women in our initial cohort: 283 used EM (4%) and 6675 (96%) did not. The median follow-up time was 46.5 months in the EM patients and 49.5 months in the non-EM patients. In a Kaplan-Meier analysis, median overall survival was 8.2 months in patients who receive EM and 6.2 months in those who did not (p = 0.004). In our 1:4 propensity-matched cohort, median follow-up was 46.5 in the EM group and 50.6 in the non-EM group; median overall survival was 8.0 months in the EM group and 6.4 months in the non-EM group (p = 0.02). In a multivariate Cox regression of the matched cohort, EM was significantly associated with overall survival (HR 0.84; 95% CI 0.73 - 0.97). All results were similar for cancer-specific survival. In our exploratory analysis, combined Estrogen-Progesterone did significantly impact overall survival (HR 0.84; 95% CI 0.71-0.99, p = 0.04) but did not appear to effect cancer-specific survival (HR 0.91; 95% CI 0.77-1.09, p = 0.30).

CONCLUSION

EM was associated with a significant improvement in cancer-specific survival and overall survival in women with late stage NSCLC.

Velocity-based Adaptive Registration and Fusion for Fractionated Stereotactic Radiosurgery Using the Small Animal Radiation Research Platform

PURPOSE

To implement Velocity-based image fusion and adaptive deformable registration to enable treatment planning for preclinical murine models of fractionated stereotactic radiosurgery (fSRS) using the small animal radiation research platform (SARRP).

METHODS AND MATERIALS

C57BL6 mice underwent 3 unique cone beam computed tomography (CBCT) scans: 2 in the prone position and a third supine. A single T1-weighted post-contrast magnetic resonance imaging (MRI) series of a murine metastatic brain tumor model was selected for MRI-to-CBCT registration and gross tumor volume (GTV) identification. Two arms were compared: Arm 1, where we performed 3 individual MRI-to-CBCT fusions using rigid registration, contouring GTVs on each, and Arm 2, where the authors performed MRI-to-CBCT fusion and contoured GTV on the first CBCT followed by Velocity-based adaptive registration. The first CBCT and associated GTV were exported from MuriPlan (Xstrahl Life Sciences) into Velocity (Varian Medical Systems, Inc, Palo Alto, CA). In Arm 1, the second and third CBCTs were exported similarly along with associated GTVs (Arm 1), while in Arm 2, the first (prone) CBCT was fused separately to the second (prone) and third (supine) CBCTs, performing deformable registrations on initial CBCTs and applying resulting matrices to the contoured GTV. Resulting GTVs were compared between Arms 1 and 2.

RESULTS

Comparing GTV overlays using repeated MRI fusion and GTV delineation (Arm 1) versus those of Velocity-based CBCT and GTV adaptive fusion (Arm 2), mean deviations ± standard deviation in the axial, sagittal, and coronal planes were 0.46 ± 0.16, 0.46 ± 0.22, and 0.37 ± 0.22 mm for prone-to-prone and 0.52 ± 0.27, 0.52 ± 0.36, and 0.68 ± 0.31 mm for prone-to-supine adaptive fusions, respectively.

CONCLUSIONS

Velocity-based adaptive fusion of CBCTs and contoured volumes allows for efficient fSRS planning using a single MRI-to-CBCT fusion. This technique is immediately implementable on current SARRP systems, facilitating advanced preclinical treatment paradigms using existing clinical treatment planning software.

Complete intracranial response to talimogene laherparepvec (T-Vec), pembrolizumab and whole brain radiotherapy in a patient with melanoma brain metastases refractory to dual checkpoint-inhibition

Background

Immunotherapy, in particular checkpoint blockade, has changed the clinical landscape of metastatic melanoma. Nonetheless, the majority of patients will either be primary refractory or progress over follow up. Management of patients progressing on first-line immunotherapy remains challenging. Expanded treatment options with combination immunotherapy has demonstrated efficacy in patients previously unresponsive to single agent or alternative combination therapy.

Case presentation

We describe the case of a patient with diffusely metastatic melanoma, including brain metastases, who, despite being treated with stereotactic radiosurgery and dual CTLA-4/PD-1 blockade (ipilimumab/nivolumab), developed systemic disease progression and innumerable brain metastases. This patient achieved a complete CNS response and partial systemic response with standard whole brain radiation therapy (WBRT) combined with Talimogene laherparepvec (T-Vec) and pembrolizumab.

Conclusion

Patients who do not respond to one immunotherapy combination may respond during treatment with an alternate combination, even in the presence of multiple brain metastases. Biomarkers are needed to assist clinicians in evidence based clinical decision making after progression on first line immunotherapy to determine whether response can be achieved with second line immunotherapy.

Single institution validation of a modified graded prognostic assessment of patients with breast cancer brain metastases

Aim:

The number of breast cancer brain metastases is a prognostic clinical variable in the modified graded prognostic assessment (GPA) Index for breast cancer.

Patients & methods:

We retrospectively gathered data from 127 breast cancer patients who underwent radiation therapy for brain metastasis. Patients were stratified by both breast GPA and modified breast GPA scores, and survival was determined using the Kaplan–Meier curves and Cox proportional hazards model.

Results & Conclusion:

The Kaplan–Meier curve for patients under the breast GPA classification were not significant, but were significant under the modified breast GPA classification. The inclusion of number of brain metastases into the modified breast GPA index improved prognosis, thus validating the use of the modified breast GPA in prognosticating patient outcome.

Clinical and molecular characteristics of gliosarcoma and modern prognostic significance relative to conventional glioblastoma

Gliosarcoma is a rare histopathologic variant of glioblastoma traditionally associated with a poor prognosis. While gliosarcoma may represent a distinct clinical entity given its unique histologic composition and molecular features, its relative prognostic significance remains uncertain. While treatment of gliosarcoma generally encompasses the same standardized approach used in glioblastoma, supporting evidence is limited given its rarity. Here, we characterized 32 cases of gliosarcoma and retrospectively evaluated survival relative to 451 glioblastoma patients diagnosed during the same era within the same institution. Overall, we identified 22 primary gliosarcomas, representing 4.7% of WHO Grade IV primary glioblastomas, and 10 secondary gliosarcomas. With median age of 62, patients were predominately Caucasian (87.5%) and male (65.6%). Tumors with available molecular profiling were primarily MGMT-unmethylated (87.5%), IDH-1-preserved (100%) and EGFR wild-type (100%). Interestingly, while no significant median survival difference between primary gliosarcoma and glioblastoma was observed across the entire cohort (11.0 vs. 14.8 months, p = 0.269), median survival was worse for gliosarcoma specifically among patients who received modern temozolomide-based (TMZ) chemoradiotherapy (11.0 vs. 17.3 months, p = 0.006). Matched-pair analysis also trended toward worse median survival among gliosarcomas (11.0 vs. 19.6 months, log-rank p = 0.177, Breslow p = 0.010). While adjuvant radiotherapy (HR 0.206, p = 0.035) and TMZ-based chemotherapy (HR 0.531, p = 0.000) appeared protective, gliosarcoma emerged as a significantly poor prognostic factor on multivariate analysis (HR 3.27, p = 0.012). Collectively, our results suggest that gliosarcoma may still portend worse prognosis even with modern trimodality therapy.

Breast cancer subtype and stage are prognostic of time from breast cancer diagnosis to brain metastasis development

Breast cancer brain metastasis (BCBM) is associated with high morbidity and mortality. Patients with breast cancer risk factors associated with rapid development of BCBM could potentially benefit from early brain metastasis screening. We retrospectively reviewed all BCBM patients treated with brain radiotherapy at our institution from 1997 to 2015. Interval time to BCBM was defined as date of pathologic breast cancer diagnosis to date of radiographic evidence of brain metastasis. Patients were stratified by breast cancer molecular subtype and stage at diagnosis. Kaplan Meier analysis was conducted on time to development of BCBM. Breast cancer risk factors were correlated with time to BCBM on Cox proportion hazard analysis. The study cohort comprised 121 BCBM patients, with median interval time to BCBM of 46 months. Times to BCBM for Her2+/2HR+, Her2+, Her2-/HR+, and triple-negative (TNBC) subtypes were 70, 44, 42, and 28 months respectively (p = 0.002). Time to BCBM for stages I, II, III, and IV were 70, 54, 29, and 24 months, respectively (p = 0.000). BCBM patients were further stratified by both molecular subtype (TNBC vs. non-TNBC) and stage (I, II vs. III, IV). Median times to BCBM for non-TNBC/stage I-II, TNBC/stage I-II, non-TNBC stage III-IV, and TNBC/stage III-IV were 68, 47, 29, and 6 months respectively (p = 0.000). Subtype and stage were associated with shorter time to BCBM on multivariate analysis. Subtype and initial stage are independently correlated with decreased time to development of BCBM. Patients with advanced high stage and triple negative breast cancer develop brain metastases significantly earlier.

Whole-brain Irradiation Field Design: A Comparison of Parotid Dose

Whole-brain radiation therapy (WBRT) plays an important role in patients with diffusely metastatic intracranial disease. Whether the extent of the radiation field design to C1 or C2 affects parotid dose and risk for developing xerostomia is unknown. The goal of this study is to examine the parotid dose based off of the inferior extent of WBRT field to either C1 or C2. Patients treated with WBRT with either 30 Gy or 37.5 Gy from 2011 to 2014 at a single institution were examined. Parotid dose constraints were compared with Radiation Therapy Oncology Group (RTOG) 0615 nasopharyngeal carcinoma for a 33-fraction treatment: mean <26 Gy, volume constraint at 20 Gy (V20) < 20 cc, and dose at 50% of the parotid volume (D50) < 30 Gy. Biologically effective dose (BED) conversions with an α/β of 3 for normal parotid were performed to compare with 10-fraction and 15-fraction treatments of WBRT. The constraints are as follows: mean < BED 32.83 Gy, V15.76 (for 10-fraction WBRT) or V17.35 (for 15-fraction WBRT) < 20 cc, and D50 < BED 39.09 Gy. Nineteen patients treated to C1 and 26 patients treated to C2 were analyzed. Comparing WBRT to C1 with WBRT to C2, the mean left, right, and both parotids' doses were lower when treated to C1. Converting mean dose to BED₃, the parotid doses were lower than BED₃ constraint of 32.83 Gy: left (30.12 Gy), right (30.69 Gy), and both parotids (30.32 Gy). V20 to combined parotids was lower in patients treated to C1. When accounting for fractionation of WBRT received, the mean corrected V20 volume was less than 20 cc when treating to C1. D50 for C1 was lower than C2 for the left parotid, right parotid, and both parotids. BED₃ conversion for the mean D50 of the left, right, and both parotids was less than 39.09 Gy. In conclusion, WBRT to C1 limits parotid dose, and parotid dose constraints are achievable compared with inferior border at C2. A possible mean parotid dose constraint with BED₃ should be less than 32.83 Gy.

Radiation-Induced Dermatitis is Mediated by IL17-Expressing γδ T Cells

Radiation dermatitis is a serious cutaneous injury caused by radiation therapy or upon accidental nuclear exposure. However, the pathogenic immune mechanisms underlying this injury are still poorly understood. We seek to discover how the dysregulated immune response after irradiation orchestrates skin inflammation. The skin on the left flank of C57BL/6J wild-type and C57BL/6J Tcrd^-/- mice, which are deficit in γδ T cells, was exposed to a single X-ray dose of 25 Gy, and the right-flank skin was used as a sham-irradiated control. At 4 weeks postirradiation, the wild-type skin exhibited signs of depilation, erythema and desquamation. Histological analysis showed hyperproliferation of keratinocytes and acanthosis. Dramatic elevation of IL17-expressing T cells was identified from the irradiated skin, which was mainly contributed by γδ T cells and innate lymphoid cells, rather than Th17 cells. Furthermore, protein levels of critical cytokines for IL17-expressing γδ T cell activation, IL1β and IL23 were found markedly upregulated. Lastly, radiation-induced dermatitis was significantly attenuated in γδ T cell knockout mice. In vitro, normal human epidermal keratinocytes (NHEKs) could be initiator cells of inflammation by providing a great number of pro-inflammatory mediators upon radiation, and as well as effector cells of epidermal hyperplasia in response to exogenous IL17 and/or IL22 treatment. Our findings implicate a novel role of IL17-expressing γδ T cells in mediating radiation-induced skin inflammation. This study reveals the innate immune response pathway as a potential therapeutic target for radiation skin injury.