[Characteristics of radiotherapy for adolescents and young adults]

Radiotherapy for adolescents and young adults is complex in several aspects. The population is very heterogeneous and has characteristics derived from both paediatric and adult populations both in terms of pathology (anatomical pathology, response to treatment) and the patient's physical, biological and psychological characteristics. This article reviews the characteristics to be taken into account in adolescent and young adult patients radiotherapy and more particularly in some of the most common diseases.

Post-operative flank irradiation using conformal versus highly conformal radiotherapy techniques for paediatric renal tumours: Results from the French registry PediaRT

PURPOSE

Three-dimensional conformal RT (3D-RT) techniques are gold standard for post-operative flank radiotherapy (RT) in paediatric renal tumours. Recently, highly conformal RT (HC-RT) techniques have been implemented without comparative clinical data. The main objective of this multicentre study was to compare locoregional control (LRC) in children treated either with HC-RT or 3D-RT techniques.

METHODS

Patients treated with post-operative flank RT for renal tumour registered in the national cohort PediaRT between March 2013 and September 2019 were included. Treatment and follow-up data, including toxicities and outcomes, were retrieved from the database. LRC was calculated, and dose reconstruction was performed in case of an event.

RESULTS

Seventy-nine patients were included. Forty patients were treated with HC-RT and 39 with 3D-RT. Median follow-up was 4.5 years. Three patients had locoregional failure (LRF; 4%). HC-RT was not associated with a higher risk of LRF. Three-year LRC were 97.4% and 94.7% in the HC-RT and 3D-RT groups, respectively. The proportion of planning target volumes receiving 95% or more of the prescribed dose did not significantly differ between both groups (HC-RT 88%; 3D-RT 69%; p = .05). HC-RT was better achieving dose constraints, and a significant mean dose reduction was observed in the peritoneal cavity and pancreas associated with lower incidence of acute gastrointestinal toxicity.

CONCLUSION

LRF after post-operative flank RT for renal tumours was rare and did not increase using HC-RT versus 3D-RT techniques. Dose to the pancreas and the peritoneal cavity, as well as acute toxicity, were reduced with HC-RT compared to 3D-RT.

Mechanistic modeling of metastatic relapse in early breast cancer to investigate the biological impact of prognostic biomarkers

BACKGROUND AND OBJECTIVE

Estimating the risk of metastatic relapse is a major challenge to decide adjuvant treatment options in early-stage breast cancer (eBC). To date, distant metastasis-free survival (DMFS) analysis mainly relies on classical, agnostic, statistical models (e.g., Cox regression). Instead, we propose here to derive mechanistic models of DMFS.

METHODS

The present series consisted of eBC patients who did not receive adjuvant systemic therapy from three datasets, composed respectively of 692 (Bergonié Institute), 591 (Paoli-Calmettes Institute, IPC), and 163 (Public Hospital Marseille, AP-HM) patients with routine clinical annotations. The last dataset also contained expression of three non-routine biomarkers. Our mechanistic model of DMFS relies on two mathematical parameters that represent growth (α) and dissemination (μ). We identified their population distributions using mixed-effects modeling. Critically, we propose a novel variable selection procedure allowing to: (i) identify the association of biological parameters with either α, μ or both, and (ii) generate an optimal candidate model for DMFS prediction.

RESULTS

We found that Ki67 and Thymidine Kinase-1 were associated with α, and nodal status and Plasminogen Activator Inhibitor-1 with μ. The predictive performances of the model were excellent in calibration but moderate in discrimination, with c-indices of 0.72 (95% CI [0.48, 0.95], AP-HM), 0.63 ([0.44, 0.83], Bergonié) and 0.60 (95% CI [0.54, 0.80], IPC).

CONCLUSIONS

Overall, we demonstrate that our novel method combining mechanistic and advanced statistical modeling is able to unravel the biological roles of clinicopathological parameters from DMFS data.

Stereotactic radiosurgery for post operative brain metastasic surgical cavities: a single institution experience

BACKGROUND

The standard therapy for brain metastasis was surgery combined with whole brain radiotherapy (WBRT). The latter is however, associated with important neurocognitive toxicity. To reduce this toxicity, postoperative stereotactic radiosurgery (SRS) is a promising technique. We assessed the efficacy and the tolerance to postoperative Gamma Knife radiosurgery (GK) on the tumor bed after resection of brain metastases.

METHODS

Between February 2011 and December 2016, following macroscopic complete surgical resection, 64 patients and 65 surgical cavities were treated by GK in our institution. The indication for adjuvant radiosurgery was a multidisciplinary decision. The main assessment criteria considered in this study were local control, intracranial metastasis-free survival (ICMFS), overall survival and toxicity.

RESULTS

Median follow-up: 11.1 months. Median time between surgery and radiosurgery: 35 days. Median dose was 20 Gy prescribed to the 50% isodose line, for a median treated volume of 5.6 cc. Four patients (7%) suffered from local recurrence. Local recurrence-free, intracranial recurrence-free and overall survival at 1 year were 97.5%, 57.6% and 62.4% respectively. In total, 23 patients (41%) suffered from intracranial recurrence outside the tumor bed. In univariate analysis: concomitant GK treatment of multiple lesions and the tumor bed was associated with a decrease in ICMFS (HR = 1.16 [1.005-1.34] p = 0.04). In multivariate analysis: a non-lung primary tumor was significantly associated with a decrease in ICMFS (HR = 8.04 [1.82-35.4] p = 0.006). An increase in performance status (PS) and in the initial number of cerebral metastases significantly reduced overall survival (HR = 5.4 [1.11-26.3] p = 0.037, HR = 2.7 [1.004-7.36] p = 0.049, respectively) and One radiation necrosis histologically proven.

CONCLUSION

Our study confirmed that postoperative GK after resection of cerebral metastases is an efficient and well-tolerated technique, to treat volumes of all sizes (0.8 to 40 cc). Iterative SRS or salvage WBRT can be performed in cases of intracranial relapse, postponing WBRT with its potential side effects.

Abstract 2737: A mechanistic model for prediction of metastatic relapse in early-stage breast cancer using routine clinical features

Estimation of the risk of metastatic relapse is a major challenge to decide treatment options for early-stage breast cancer patients. To date, metastasis free survival (MFS) analysis mainly relies on classical - agnostic - statistical models (e.g., Cox regression). Instead, we propose to derive mechanistic models to predict MFS.

The data consisted of patients who did not receive adjuvant systemic therapy from two databases: one (data 1, N = 163) with routine clinical features and the PAI-1 and uPA biomarkers and two (data 2, N = 692) with 11 routine clinical features. The mathematical models are based on a partial differential equation describing a size-structured population of metastases. They predict MFS from the size of the tumor at diagnosis and two mathematical parameters, α and μ describing respectively the tumor growth speed and metastatic dissemination potential. Using mixed-effects modeling, the population distributions of α and μ were assumed to be lognormal and to depend on routine clinical variables, whereas the observation error was assumed lognormal on the time-to-relapse. Variable selection consisted first in a univariate Wald test for all covariates with effect either on α or μ. We then used a backward elimination procedure. Significance of the covariates in the final model was assessed by a multivariable Wald test. Concordance indexes (c-index) were computed to assess the predictive power in cross-validation procedures as well as test sets.

The model was implemented as an R package using optimized C++ code for the mechanistic part and enabling parallelization, resulting in a 4-fold reduction of the computing compared to a former python implementation. Nevertheless, over 4 hours are still needed to run a 100 samples bootstrap on a distributed computing cluster. The model selection procedure on data 1 revealed an association of PAI1 and age with μ, and of Estrogen receptor level with alpha, consistent with the established biological link between PAI-1 and tumor invasiveness. The resulting model achieved good prediction performances with a c-index of 0.72 in 5 folds cross-validation. Using only routine clinical markers, the algorithm on data 2 selected a model with the grade and Progesterone Receptors in α, Ki67 and node status in μ. These were able to adequately describe the data on calibration plots but performed poorly in prediction with a cross validated c-index of 0.60.

Mechanistic modeling was able to unravel the biological and predictive role of PAI-1 but showed limited predictive power when using only on routine clinical features.

Citation Format: Célestin Bigarré, Pascal Finetti, François Bertucci, Xavier Muracciole, Sébastien Benzekry. A mechanistic model for prediction of metastatic relapse in early-stage breast cancer using routine clinical features [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 2737.

High-dose chemotherapy followed by autologous stem cell rescue in Wilms tumors: French report on toxicity and efficacy

BACKGROUND

Heterogeneous data have been reported on high-dose chemotherapy (HDCT) with autologous stem cell rescue (ASCR) in Wilms tumors (WTs). We aimed to define its safety and efficacy in the French cohort, and to compare this management to current international recommendations.

METHODS

Data prospectively collected from children, adolescents, and young adults with WT treated with HDCT/ASCR between 2000 and 2016 in French centers were retrospectively analyzed. Toxicity was reported according to CTCAE v4.03.

RESULTS

Fifty-four patients received HDCT/ASCR (first line, n = 13; recurrence, n = 41). Their median age at the time of ASCR was 5.3 years (range 2.2-21.6). Main nonhematological acute grades 3-4 toxicities were digestive and renal. No significant difference of toxicity rate was observed among HDCT regimens and schedules. Two patients died shortly after ASCR (renal and multiorgan failure), and one heavily pretreated patient died of late respiratory failure. The selection criteria applied to define those patients eligible for HDCT/ASCR retrospectively matched to those currently used in the International Society of Pediatric Oncology (SIOP) UMBRELLA protocol for 38 patients, with encouraging survival rates compared to published data. The objective response rate to HDCT was 21%, with a disease control rate after HDCT of 85%. After a median follow-up of 7 years, the 5-year event-free survival (EFS) and overall survival (OS) were 54% (95% CI: 32%-76%) and 62% (95% CI: 31%-82%) for frontline patients, and 57% (95% CI: 39%-71%) and 69% (95% CI: 52%-81%) at recurrence.

CONCLUSION

HDCT was feasible and showed encouraging results in well-defined settings. Data from the current prospective protocol will help to better evaluate HDCT impact on survival.

HoSAGE: sarcopenia in older patient with intermediate / high-risk prostate cancer, prevalence and incidence after androgen deprivation therapy: study protocol for a cohort trial

Background

Sarcopenia is defined by a loss of muscle strength associated to a decrease in skeletal muscle mass. Ageing greatly contributes to sarcopenia as may many other factors such as cancer or androgen deprivation therapies (ADT). This cohort study aims to evaluate (1) the prevalence of muscle disorders and sarcopenia in older patients before initiation of intermediate to high risk prostate cancer treatment with ADT and radiotherapy, and (2) the occurrence and/or aggravation of muscle disorders and sarcopenia at the end of cancer treatment.

Methods

This cohort study is monocentric and prospective. The primary objectives are to determine the risk factor of sarcopenia prevalence and to study the relationship between ADT and sarcopenia incidence, in patients 70 years and older with histologically proven localized or locally advanced prostate cancer, addressed to a geriatrician (G8 score ≤14) for comprehensive geriatric assessment (CGA) in Marseille University Hospital. Secondary objectives encompass, measurement of sarcopenia clinical criteria along prostate oncological treatment; evaluation of the quality of life of patients with sarcopenia; evaluation of the impact of socio-behavioral and anthropological factors on sarcopenia evolution and incidence; finally the evaluation of the impact of ADT exposure on sarcopenia. Sarcopenia prevalence was estimated to be between 20 and 30%, therefore the study will enroll 200 patients.

Discussion

The current guidelines for older patients with prostate cancer recommend a pelvic radiotherapy treatment associated to variable duration (6 to 36 months) of ADT. However ADT impacts muscle mass and could exacerbate the risks of sarcopenia. Our study intends to assess the specific effect of ADT on sarcopenia incidence and/or worsening as well as to estimate sarcopenia prevalence in this population. The results of this cohort trial will lead to a better understanding of sarcopenia prevalence and incidence necessary to further elaborate a prevention plan.

Trial registration

The protocol was registered to the French drug and device regulation agency under the number 2019-A02319-48, before beginning the study (11/12/2019). The ClinicalTrials.gov identifier is NCT04484246, registration on the ClinicalTrials.gov (https://clinicaltrials.gov/ct2/show/NCT04484246).

Mask-Based versus Frame-Based Gamma Knife ICON Radiosurgery in Brain Metastases: A Prospective Randomized Trial

BACKGROUND

Radiosurgery is performed with a diversity of instruments relying usually either on a stereotactic frame or a mask for patient head fixation. Comfort and safety efficacy of the 2 systems have never been rigorously evaluated and compared.

MATERIAL AND METHOD

Between February 2016 and January 2017, 58 patients presenting with nonsmall cell lung cancer brain metastases have been treated by Gamma Knife radiosurgery (GKS) with random use of a frame or a mask for fixation were included patients older than 18, with <5 brain metastases (at the exclusion of brainstem and optic pathway's locations) and no earlier history of radiotherapy. The primary outcome measure was the pain scale assessment (PSA) at the beginning of the GKS procedure.

RESULTS

The PSA at the beginning of the GKS procedure was not different between the 2 groups. The PSA at the day before GKS, before magnetic resonance imaging, just after frame application, and the day after radiosurgery (departure) has shown no difference between the 2 groups. At the end of the radiosurgery itself (just after frame or mask removal) and 1 h after, the mean pain scale was higher in patients treated with the frame (p < 0.05 and p < 0.001, respectively) but 2 patients were not able to tolerate the mask discomfort and had to be treated with frame. Tumor control and morbidity probability were demonstrated to be no difference between the 2 groups in this population of patients with BM not in highly functional area. The median of the extra dose to the body due to the cone-beam computed tomography was 7.5 mGy with a maximum of 35 mGy in patients treated with a mask fixation (null in the others treated with frame). Mask fixation was associated to longer treatment time although the beam on time was not different between the 2 groups.

CONCLUSION

In selected patients, with brain oligo-metastases out of critical location, single-dose mask-based GKS can be done with a comfort and a safety efficacy comparable to frame-based GKS. There seems to be no clear patient data that confirm the value of the mask system with regards to comfort.

Lymphovascular invasion has a significant prognostic impact in patients with early breast cancer, results from a large, national, multicenter, retrospective cohort study

Background

We determined the prognostic impact of lymphovascular invasion (LVI) in a large, national, multicenter, retrospective cohort of patients with early breast cancer (BC) according to numerous factors.

Patients and methods

We collected data on 17 322 early BC patients treated in 13 French cancer centers from 1991 to 2013. Survival functions were calculated using the Kaplan–Meier method and multivariate survival analyses were carried out using the Cox proportional hazards regression model adjusted for significant variables associated with LVI or not. Two propensity score-based matching approaches were used to balance differences in known prognostic variables associated with LVI status and to assess the impact of adjuvant chemotherapy (AC) in LVI-positive luminal A-like patients.

Results

LVI was present in 24.3% (4205) of patients. LVI was significantly and independently associated with all clinical and pathological characteristics analyzed in the entire population and according to endocrine receptor (ER) status except for the time period in binary logistic regression. According to multivariate analyses including ER status, AC, grade, and tumor subtypes, the presence of LVI was significantly associated with a negative prognostic impact on overall (OS), disease-free (DFS), and metastasis-free survival (MFS) in all patients [hazard ratio (HR) = 1.345, HR = 1.312, and HR = 1.415, respectively; P < 0.0001], which was also observed in the propensity score-based analysis in addition to the association of AC with a significant increase in both OS and DFS in LVI-positive luminal A-like patients. LVI did not have a significant impact in either patients with ER-positive grade 3 tumors or those with AC-treated luminal A-like tumors.

Conclusion

The presence of LVI has an independent negative prognostic impact on OS, DFS, and MFS in early BC patients, except in ER-positive grade 3 tumors and in those with luminal A-like tumors treated with AC. Therefore, LVI may indicate the existence of a subset of luminal A-like patients who may still benefit from adjuvant therapy.

•

In a study of 17 322 early BC patients, LVI had a significant independent negative prognostic impact on survival.

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LVI negatively impacted survival in almost every patient category and cancer subtype, with and without AC.

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LVI did not have a negative survival impact in patients with ER+ grade 3 or with luminal A-like tumors with chemotherapy.

•

Results suggest a possible benefit of AC in LVI-positive luminal A-like patients.

Stereotactic Body Radiotherapy for Frail Patients with Primary Renal Cell Carcinoma: Preliminary Results after 4 Years of Experience

Simple Summary

Surgical therapy is currently the standard of care for the treatment of primary renal cell carcinoma (RCC). Alternative strategies such as stereotactic body radiotherapy (SBRT) have emerged as potentially curative treatment approaches. In this study, we show a promising short-term local control effect of SBRT in the management of primary RCC. The treatment was well tolerated with no high-grade side effects. The main advantages are the outpatient management without anesthesia and the non-invasive approach. Thus, SBRT appears to be a promising alternative to surgery, or ablative therapy, to treat primary RCC in patients with poor physical health. Future studies are needed to definitively assess the place of SBRT in the RCC treatment portfolio.

Abstract

Introduction: The aim of this study was to report the oncological outcomes and toxicity of stereotactic body radiotherapy (SBRT) to treat primary renal cell carcinoma (RCC) in frail patients unfit for surgery or standard alternative ablative therapies. Methods: We retrospectively enrolled 23 patients who had SBRT for primary, biopsy-proven RCC at our tertiary center between October 2016 and March 2020. Treatment-related toxicities were defined using CTCAE, version 4.0. The primary outcome was local control which was defined using the Response Evaluation Criteria in Solid Tumors. Results: The median age, Charlson score and tumor size were 81 (IQR 79–85) years, 7 (IQR 5–8) and 40 (IQR 28–48) mm, respectively. The most used dose fractionation schedule was 35 Gy (78.3%) in five or seven fractions. The median duration of follow-up for all living patients was 22 (IQR 10–39) months. Local recurrence-free survival, event-free survival, cancer-specific survival and overall survival were 96 (22/23), 74 (18/23), 96 (22/23) and 83% (19/23), respectively. There were no grade 3–4 side effects. No patients required dialysis during the study period. No treatment-related deaths or late complications were reported. Conclusion: SBRT appears to be a promising alternative to surgery or ablative therapy to treat primary RCC in frail patients.

Outcome of Stage IV Completely Necrotic Wilms Tumour and Local Stage III Treated According to the SIOP 2001 Protocol

Simple Summary

Around 15–20% of all Wilms tumour (WT) patients present with metastatic disease. Approximately 10% of these patients achieve complete necrosis after preoperative chemotherapy, which is associated with a favourable prognosis. The aim of this observational study is to describe the outcome of metastatic patients with completely necrotic (low-risk histology), local stage III WT treated according to the SIOP 2001 protocol, whether or not postoperative radiotherapy was applied.

Abstract

Objective: Wilms tumour (WT) patients with a localised completely necrotic nephroblastoma after preoperative chemotherapy are a favourable outcome group. Since the introduction of the SIOP 2001 protocol, the SIOP– Renal Tumour Study Group (SIOP–RTSG) has omitted radiotherapy for such patients with low-risk, local stage III in an attempt to reduce treatment burden. However, for metastatic patients with local stage III, completely necrotic WT, the recommendations led to ambiguous use. The purpose of this descriptive study is to demonstrate the outcomes of patients with metastatic, completely necrotic and local stage III WT in relation to the application of radiotherapy or not. Methods and materials: all metastatic patients with local stage III, completely necrotic WT after 6 weeks of preoperative chemotherapy who were registered in the SIOP 2001 study were included in this analysis. The pattern of recurrence according to the usage of radiation treatment and 5 year event-free survival (EFS) and overall survival (OS) was analysed. Results: seven hundred and three metastatic WT patients were registered in the SIOP 2001 database. Of them, 47 patients had a completely necrotic, local stage III WT: 45 lung metastases (11 combined localisations), 1 liver/peritoneal, and 1 tumour thrombus in the renal vein and the inferior vena cava with bilateral pulmonary arterial embolism. Abdominal radiotherapy was administered in 29 patients (62%; 29 flank/abdominal irradiation and 9 combined with lung irradiation). Eighteen patients did not receive radiotherapy. Median follow-up was 6.6 years (range 1–151 months). Two of the 47 patients (4%) developed disease recurrence in the lung (one combined with abdominal relapse) and eventually died of the disease. Both patients had received abdominal radiotherapy, one of them combined with lung irradiation. Five-year EFS and OS were 95% and 95%, respectively. Conclusions: the outcome of patients with stage IV, local stage III, completely necrotic Wilms tumours is excellent. Our results suggest that abdominal irradiation in this patient category may not be of added value in first-line treatment, consistent with the current recommendation in the SIOP–RTSG 2016 UMBRELLA protocol.

Impact of Androgen Deprivation Therapy Associated to Conformal Radiotherapy in the Treatment of D'Amico Intermediate-/High-Risk Prostate Cancer in Older Patients

PURPOSE/OBJECTIVE

The association of 3D Conformal External Beam Radiotherapy (3D-CEBRT) with adjuvant Androgen Deprivation Therapy (ADT) proved to treat patients with intermediate- and high-risk localized prostate cancer (IR and HR). However, older patients were underrepresented in literature. We aimed to report the oncological results and morbidity 3D-CEBRT +ADT in ≥80 years patients.

MATERIAL AND METHODS

From June 1998 to July 2017, 101 patients ≥80 years were included in a tertiary center. The median age was 82 years. ADT was initiated 3 months prior 3D-CEBRT in all patients, with a total duration of 6 months for IR prostate cancer (group A; n = 41) and 15 months for HR prostate cancer (group B; n = 60). Endpoints included overall survival (OS), metastasis-free survival (DMFS), biochemical recurrence-free survival (BRFS) and toxicity.

RESULTS

Five years-OS was 95% and 86.7% in groups A and B, respectively. Cardiovascular events occurred in 22.8% of ≥80 years patients with no impact on OS. In the multivariate analysis, age <82 years, Karnofsky index and normalization of testosterone levels were significantly associated with better OS.

CONCLUSION

Age ≥80 years should not be a limitation for the treatment of IR and HR prostate cancer patients with 3D-CEBRT and ADT, but cardiovascular monitoring and prevention are mandatory.

Exclusive Hyperfractionated Radiation Therapy and Reduced Boost Volume for Standard-Risk Medulloblastoma: Pooled Analysis of the 2 French Multicentric Studies MSFOP98 and MSFOP 2007 and Correlation With Molecular Subgroups

PURPOSE

Medulloblastoma has recently been characterized as a heterogeneous disease with 4 distinct molecular subgroups: wingless (WNT), sonic hedgehog (SHH), group 3, and group 4, with a new definition of risk stratification. We report progression-free survival, overall survival, and long-term cognitive effects in children with standard-risk medulloblastoma exclusively treated with hyperfractionated radiation therapy (HFRT), reduced boost volume, and online quality control, and we explore the prognostic value of biological characteristics in this chemotherapy-naïve population.

METHODS AND MATERIALS

Patients with standard-risk medulloblastoma were enrolled in 2 successive prospective multicentric studies, MSFOP 98 and MSFOP 2007, and received exclusive HFRT (36 Gy, 1 Gy/fraction twice daily) to the craniospinal axis followed by a boost at 68 Gy restricted to the tumor bed (1.5 cm margin), with online quality assurance before treatment. Patients with MYC or MYCN amplification were not excluded at the time of the study. We report progression-free survival and overall survival in the global population, and according to molecular subgroups as per World Health Organization 2016 molecular classification, and we present cognitive evaluations based on the Wechsler scale.

RESULTS

Data from 114 patients included in the MSFOP 98 trial from December 1998 to October 2001 (n = 48) and in the MSFOP 2007 from October 2008 to July 2013 (n = 66) were analyzed. With a median follow-up of 16.2 (range, 6.4-19.6) years for the MSFOP 98 cohort and 6.5 (1.6-9.6) years for the MSFOP 2007 cohort, 5-year overall survival and progression-free survival in the global population were 84% (74%-89%) and 74% (65%-81%), respectively. Molecular classification was determined for 91 patients (WNT [n = 19], SHH [n = 12], and non-WNT/non-SHH [n = 60]-including group 3 [n = 9], group 4 [n = 29], and not specified [n = 22]). Our results showed more favorable outcome for the WNT-activated subgroup and a worse prognosis for SHH-activated patients. Three patients had isolated extra-central nervous system relapse. The slope of neurocognitive decline in the global population was shallower than that observed in patients with a normofractionated regimen combined with chemotherapy.

CONCLUSIONS

HFRT led to a 5-year survival rate similar to other treatments combined with chemotherapy, with a reduced treatment duration of only 6 weeks. We confirm the MSFOP 98 results and the prognostic value of molecular status in patients with medulloblastoma, even in the absence of chemotherapy. Intelligence quotient was more preserved in children with medulloblastoma who received exclusive HFRT and reduced local boost, and intelligence quotient decline was delayed compared with patients receiving standard regimen. HFRT may be appropriate for patients who do not consent to or are not eligible for prospective clinical trials; for patients from developing countries for whom aplasia or ileus may be difficult to manage in a context of high cost/effectiveness constraints; and for whom shortened duration of RT may be easier to implement.

Effect of Adding Docetaxel to Androgen-Deprivation Therapy in Patients With High-Risk Prostate Cancer With Rising Prostate-Specific Antigen Levels After Primary Local Therapy: A Randomized Clinical Trial

Importance

Androgen-deprivation therapy (ADT) plus docetaxel is the standard of care in hormone-naive metastatic prostate cancer but is of uncertain benefit in a nonmetastatic, high-risk prostate cancer setting.

Objective

To assess the benefit of ADT plus docetaxel in patients presenting with rising prostate-specific antigen (PSA) levels after primary local therapy and high-risk factors but no evidence of metastatic disease.

Design, Setting, and Participants

This open-label, phase 3, randomized superiority trial comparing ADT plus docetaxel vs ADT alone enrolled patients from 28 centers in France between June 4, 2003, and September 25, 2007; final follow-up was conducted April 12, 2017, and analysis was performed May 2 to July 31, 2017. Patients had undergone primary local therapy for prostate cancer, were experiencing rising PSA levels, and were considered to be at high risk of metastatic disease. Stratification was by prior local therapy and PSA-level doubling time (≤6 vs >6 months), and intention-to-treat analysis was used.

Interventions

Patients were randomly assigned to receive ADT (1 year) plus docetaxel, 70 mg/m2 (every 3 weeks [6 cycles]), or ADT alone (1 year).

Main Outcomes and Measures

The primary outcome was PSA progression-free survival (PSA-PFS). Secondary end points were PSA response, radiologic PFS, overall survival, safety, and quality of life.

Results

Overall, 254 patients were randomized (1:1) to the trial; median age, 64 years in the ADT plus docetaxel arm, 66 years in the ADT alone arm. At a median follow-up of 30.0 months, the median PSA-PFS was 20.3 (95% CI, 19.0-21.6) months in the ADT plus docetaxel arm vs 19.3 (95% CI, 18.2-20.8) months in the ADT alone arm (hazard ratio [HR], 0.85; 95% CI, 0.62-1.16; P = .31). At a median follow-up of 10.5 years, there was no significant between-arm difference in radiologic PFS (HR, 1.03; 95% CI, 0.74-1.43; P = .88). Overall survival data were not mature. The most common grade 3 or 4 hematologic toxic effects in the ADT plus docetaxel arm were neutropenia (60 of 125 patients [48.0%]), febrile neutropenia (10 [8.0%]), and thrombocytopenia (4 [3.0%]). There was no significant between-arm difference in overall quality of life.

Conclusions and Relevance

Compared with ADT alone, combined ADT plus docetaxel therapy with curative intent did not significantly improve PSA-PFS in patients with high-risk prostate cancer and rising PSA levels and no evidence of metastatic disease.

Trial Registration

French Health Products Safety Agency identifier: 030591; ClinicalTrials.gov identifier: NCT00764166.

The outcomes of a second and third Gamma Knife radiosurgery for recurrent essential glossopharyngeal neuralgia

INTRODUCTION

Gamma Knife radiosurgery (GKR) is a minimally invasive surgical option for drug-resistant essential glossopharyngeal neuralgia (GPN). The authors reviewed pain outcomes and complications in GPN patients who underwent a second or a third GKR for recurrent or persistent pain.

METHODS

A retrospective review of all patients treated in a single center (Marseille, France) since 2004 was performed. Median prescribed dose was 85 Gy (range 70-90 Gy) at second GKR and 85 Gy at third GKR. Clinical outcome was evaluated using the Barrow Neurological Institute (BNI) scale.

RESULTS

Six patients (4 males, 2 females) underwent second or third GKR. The median age was 70.2 years (range 64-83 years) at second GKR and 79.8 years at third GKR. No patient had any previous surgery but GKR. Five cases had a neurovascular conflict. Median follow-up period was 12 months (range 10-94 months) after second GKR and 16 months after third GKR. The median delay to initial pain freedom response was 30 days (range 3-120 days). One patient experienced pharyngeal hypoesthesia after second GKR. After a third GKR, up to 16 months, no side effects were encountered. At the last follow-up, 3 patients were BNI I, 2 were BNI IIIa, and one did not have any improvement.

CONCLUSIONS

Second GKR resulted in pain reduction with low risk of additional morbidity. In patients unsuitable for microvascular decompression, GKR as a repeat or third treatment for intractable GPN is safe and effective. Third GKR was not associated with any side effects up to 16 months after the procedure.

HoSAGE: Sarcopenia in Older Patients before and after Treatment with Androgen Deprivation Therapy and Radiotherapy for Prostate Cancer

BACKGROUND

Sarcopenia is a muscle disease defined by a loss of muscle strength associated to a decrease in skeletal muscle mass. In addition to aging, many factors may contribute to sarcopenia as cancer and/or androgen deprivation therapy (ADT).

OBJECTIVES

The aims of this study are to describe the prevalence of sarcopenia in older prostate cancer patients before initiation of treatment with ADT and radiotherapy, and to evaluate the impact of ADT on the occurrence or aggravation of sarcopenia in this population.

DESIGN

longitudinal study.

PARTICIPANTS AND SETTING

Sarcopenia was prospectively evaluated in 31 consecutive patients aged 70 to 88 years, referred in one hospital unit of south eastern France, for a comprehensive geriatric assessment (CGA) before cancer treatment initiation.

MEASUREMENTS AND RESULTS

CGA, measures of muscle strength and physical performances were performed at baseline (T0) and at the end of cancer treatment (T1). Appendicular skeletal muscle mass was measured by Dual-energy X-ray absorptiometry (DXA) at the end of treatment. At T0, 8 patients (among 31) had a probable sarcopenia according to European consensus, and 18 had altered physical performance. At T1, 15 patients (among 19) had abnormal one leg balance test. Finally, only one patient had a sarcopenia confirmed by DXA.

CONCLUSION

This preliminary study showed a high prevalence of muscle disorders before initiation of ADT in a population of elderly cancer prostate patients with intermediate frailty status, and an increased risk of falls at the end of ADT. This highlighted the importance of screening for sarcopenia before treatment initiation, to prevent the occurrence or aggravation of sarcopenia by possible adjustment of treatment, and implementation of appropriate exercise and nutrition interventions.

Feasibility of Dose Escalation in Patients With Intracranial Pediatric Ependymoma

Background and purpose: Pediatric ependymoma carries a dismal prognosis, mainly owing to local relapse within RT fields. The current prospective European approach is to increase the radiation dose with a sequential hypofractionated stereotactic boost. In this study, we assessed the possibility of using a simultaneous integrated boost (SIB), comparing VMAT vs. IMPT dose delivery.

Material and methods: The cohort included 101 patients. The dose to planning target volume (PTV59.4) was 59.4/1.8 Gy, and the dose to SIB volume (PTV67.6) was 67.6/2.05 Gy. Gross tumor volume (GTV) was defined as the tumor bed plus residual tumor, clinical target volume (CTV59.4) was GTV + 5 mm, and PTV59.4 was CTV59.4 + 3 mm. PTV67.6 was GTV+ 3 mm. After treatment plan optimization, quality indices and doses to target volume and organs at risk (OARs) were extracted and compared with the standard radiation doses that were actually delivered (median = 59.4 Gy [50.4 59.4]).

Results: In most cases, the proton treatment resulted in higher quality indices (p < 0.001). Compared with the doses that were initially delivered, mean, and maximum doses to some OARs were no higher with SIB VMAT, and significantly lower with protons (p < 0.001). In the case of posterior fossa tumor, there was a lower dose to the brainstem with protons, in terms of V59 Gy, mean, and near-maximum (D2%) doses.

Conclusion: Dose escalation with intensity-modulated proton or photon SIB is feasible in some patients. This approach could be considered for children with unresectable residue or post-operative FLAIR abnormalities, particularly if they have supratentorial tumors. It should not be considered for infratentorial tumors encasing the brainstem or extending to the medulla.

Negative Survival Impact of High Radiation Doses to Neural Stem Cells Niches in an IDH-Wild-Type Glioblastoma Population

Aims: Assess the impact of radiation doses to neural stem cell (NSC) niches in patients with IDH-wild-type glioblastoma.

Materials and Methods: Fifty patients were included in the study. NSC niches [SubVentricular Zone (SVZ) and Sub Granular Zone (SGZ)] were contoured by fusing CT scans and pre-therapy MRI, Tumor location defined ipsilateral and contralateral SVZ and SGZ. Prognostic significance of clinical, biological and dosimetric parameters were examined. We generated a Recursive Partitioning Analysis (RPA) model with independent prognostic classes.

Results: Median follow-up: 23.8 months. Event free and overall survival (OS): 10 and 19.1 months. Incomplete surgery, PTV (planning target volume), ipsilateral SVZ or NSC niche mean dose > 57.4 Gy, contralateral NSC niche mean dose > 35 Gy and bilateral NSC niche mean dose > 44 Gy were significantly correlated with reduced OS. Only EGFR amplification was an independent prognostic factor (p = 0.019) for OS. RPA generated independent risk groups: 1 (low risk): [ipsilateral NSC mean dose (INMD) < 58.01 Gy and methylated MGMT promoter], 2: (INMD < 58.01 Gy and unmethylated MGMT promoter and contralateral SVZ mean dose < 18.6 Gy; p = 0.43), 3: (INMD < 58.01 Gy and unmethylated MGMT promoter and contralateral SVZ mean dose > 18.6 Gy; p = 0.002) and 4: (very high risk) (INMD > 58.01 Gy; p < 0.001).

Conclusion: High radiation doses to ipsilateral NSC and contralateral SVZ could have a negative impact on overall survival in IDH-wild-type glioblastoma population.

Immunologically effective dose: a practical model for immuno-radiotherapy

Objectives

Concomitant radiotherapy with immune checkpoint blockade could be synergistic. Out-of-field effects could improve survival by slowing or blocking metastatic spreading. However, not much is known about the optimal size per fraction and inter-fraction time in that new context.

Methods

The new concept of Immunologically Effective Dose (IED) is proposed: it models an intrinsic immunogenicity of radiotherapy schedules, i.e. the fraction of immunogenicity that results from the choice of the dosing regimen. The IED is defined as the single dose, given in infinitely low dose rate, that produces the same amount of abscopal response as the radiation schedule being considered. The IED uses the classic parameters of the BED formula and adds two parameters for immunogenicity that describe the local availability of immune effectors within the tumor micro-environment. Fundamentally, the IED adds a time dimension in the BED formula and describes an intrinsic immunogenicity level for radiotherapy.

Results

The IED is positively related to the intensity of the out-of-field, radiotherapy-mediated, immune effects described in some preclinical data. Examples of numerical simulations are given for various schedules. A web-based calculator is freely available.

Conclusions

Out-of-field effects of radiotherapy with immune checkpoint blockers might be better predicted and eventually, radiotherapy schedules with better local and systemic immunogenicity could be proposed.

Advances in knowledge

A model for the intrinsic level of immunogenicity of radiotherapy schedules, referred to as the Immunologically Effective Dose (IED), that is independent of the type of immunotherapy.

Daily Versus Weekly Prostate Cancer Image Guided Radiation Therapy: Phase 3 Multicenter Randomized Trial

PURPOSE

The optimal frequency of prostate cancer image guided radiation therapy (IGRT) has not yet been clearly identified. This study sought to compare the safety and efficacy of daily versus weekly IGRT.

MATERIALS AND METHODS

This phase 3 randomized trial recruited patients with N0 localized prostate cancer. The total IGRT doses in the prostate ranged from 70 Gy to 80 Gy, sparing the lymph nodes. Patients were randomly assigned (1:1) to 2 prostate IGRT frequency groups: daily and weekly (ie, on days 1, 2, and 3 and then weekly). The primary outcome was 5-year recurrence-free survival. Secondary outcomes included overall survival and toxicity. Post hoc analyses included biochemical progression-free interval, clinical progression-free interval, and other cancer-free interval.

RESULTS

Between June 2007 and November 2012, 470 men from 21 centers were randomized into the 2 groups. Median follow-up was 4.1 years. There was no statistically significant difference in recurrence-free survival between the groups (hazard ratio [HR] = 0.81; P = .330). Overall survival was worse in the daily group than in the weekly group (HR = 2.12 [95% confidence interval (CI), 1.03-4.37]; P = .042). Acute rectal bleeding (grade ≥1) was significantly lower in the daily group (6%) (n = 14) than in the weekly group (11%) (n = 26) (P = .014). Late rectal toxicity (grade ≥1) was significantly lower in the daily group (HR = 0.71 [95% CI, 0.53-0.96]; P = .027). Biochemical progression-free interval (HR = 0.45 [95% CI, 0.25 - 0.80]; P = .007) and clinical progression-free interval (HR = 0.50 [95% CI, 0.24-1.02]; P = .057) were better in the daily group, whereas other cancer-free interval was worse in the daily group (HR = 2.21 [95% CI, 1.10-4.44]; P = .026).

CONCLUSIONS

Compared with weekly control, daily IGRT control in prostate cancer significantly improves biochemical progression-free and clinical progression-free interval, and rectal toxicity.

Daily versus weekly prostate cancer image-guided radiotherapy: A phase 3, multicenter, randomized trial

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Background: The optimal frequency of prostate cancer image-guided radiation therapy (IGRT) has not yet been clearly identified. This study sought to compare the safety and efficacy of daily versus weekly IGRT. Methods: This Phase III randomized trial recruited 470 patients with N0 localized prostate cancer, from 21 centers between June 2007 and November 2012. Total IGRT doses ranged from 70 to 80 Gy. Patients were randomly assigned (1:1) to two prostate IGRT control frequency groups: daily or weekly (Days 1, 2, and 3, then weekly). The primary outcome was 5-year recurrence-free survival (RFS). Secondary outcomes included overall survival (OS) and toxicity (CTCAE V.3.0). Post-hoc analyses included biochemical progression-free interval (BPFI), clinical progression-free interval (CPFI) and second cancer-free interval (SCFI). Results: Median follow-up was 4.1 years (Q1 – Q3 = 3.1 – 5.1).There was no statistically-significant difference in RFS between the groups (hazard ratio [HR] = 0.81 [95% CI: 0.52 – 1.25]; p = 0.330). OS was worse in the daily control group versus the weekly control group (HR = 2.12 [95% CI: 1.03 – 4.37]; p = 0.042). Late rectal toxicity (Grade ≥1) incidence was significantly lower in the daily control group (HR = 0.71 [95% CI: 0.53 – 0.96]; p = 0.027). BPFI was better in the daily control group versus the weekly control group (HR = 0.45 [95% CI: 0.25 – 0.80]; p = 0.007). CPFI was better in the daily control group (HR = 0.50 [95% CI: 0.24 – 1.02]; p = 0.057). SCFI was worse in the daily control group versus the weekly control group (HR = 2.21 [95% CI: 1.10 – 4.44]; p = 0.026). Conclusions: Compared to weekly control, daily IGRT control in prostate cancer significantly decreases the risks of recurrence and late rectal toxicity but is associated with an increased risk of second cancer. Clinical trial information: NCT00433706.

Abstract P1-13-04: Impact of hormone receptor status in HER2-Positive early breast cancer in the trastuzumab era: Results of a National multi-institutional study

Background: Recent updated analysis of the HERA (HERceptin Adjuvant) trial indicate that tumor hormone receptor status (HR)remains a major determinant of outcome in HER2-positive (HER2+) early breast cancer (BC) patients, with higher rates of recurrence and death in women with HR-negative (HR-) disease, even after 11 years' median follow-up. Furthermore, data reported from the HERA trial suggest that the timing of recurrences is different, with an initial higher frequency of disease-free survival (DFS) events in patients with HR- disease than those with HR-positive disease (HR+). No evidence of a different trastuzumab efficacy according to the HR of the primary tumor was found. In this study, we examined the impact of HR on outcome in a large, multicenter, “real-world”, retrospective cohort of HER2+ early breast cancer patients

Methods: HER2+ BC were retrospectively identified from a large cohort of 23,375 consecutive patients who underwent primary surgery at 17 French centers between Dec 1987 and Jan 2014. A multivariate Cox model was built including age, tumor size, SBR grade, lymphovascular invasion, lymph node involvement, hormonal receptors status, adjuvant chemotherapy, adjuvant hormone therapy, trastuzumab, radiotherapy and type of surgery.

Results: A total of 1308 cases were identified, including 829 (63%) HR+ and 479 (47%) HR- patients. Median follow-up was 52 months (range 0 to 201). Compared with HR+, HR- patients had significantly smaller tumors (37 vs. 31% ≤ 10mm, p=0.027; information for multifocal tumors was not available), with higher SBR grade (58 vs. 40% grade 3, p&lt;0.001) and had more lymph nodes involvement (41 vs. 32% pN+, p=0.001). HR- patients were more frequently treated by mastectomy (41 vs. 31%, p&lt;0.001), received more trastuzumab (63 vs. 53%, p&lt;0.001) and less radiotherapy (85 vs. 89%, p=0.020). Endocrine therapy was administered in 90% (744) of HR+ patients. No other significant difference in patient, tumor or treatment characteristics was found. HR status impacted DFS, metastasis free-survival (MFS) and BC-Specific survival (BC-SS) (hazard ratios: 0.46 [0.32-0.66]; p&lt;0.001, 0.52 [0.33-0.82]; p=0.004 and 0.56 [0.34-0.90]; p=0.017, respectively), log-rank test) in overall population with higher rates of recurrence and death in women with HR- disease. In multivariate analysis, lymph node involvement and use of trastuzumab but not HR status impacted significantly DFS, MFS and BC-SS. Considering patients by treatment groups (with or without trastuzumab), HR status was not predictive of survival outcomes in the trastuzumab group, as opposed to the group without trastuzumab. Regarding the timing of recurrences, we observed an increased tendency for later relapse in patients with HR+ disease compared with HR- disease, for both DFS and MFS events.

Conclusions: Our results suggest that HR status remains a major determinant of outcome in HER2+ BC, including the timing of recurrence. Yet, this prognostic impact appears to be mitigated by trastuzumab-based adjuvant treatment.

Citation Format: de Nonneville A, Gonçalves A, Cohen M, Reyal F, Classe JM, Giard S, Colombo PE, Muracciole X, Chopin N, Lambaudie E, Houvenaeghel G. Impact of hormone receptor status in HER2-Positive early breast cancer in the trastuzumab era: Results of a National multi-institutional study [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P1-13-04.

Coxiella burnetii Lipopolysaccharide: What Do We Know?

A small gram-negative bacterium, Coxiella burnetii (C. burnetii), is responsible for a zoonosis called Q fever. C. burnetii is an intracellular bacterium that can survive inside microbicidal cells like monocytes and macrophages by hijacking several functions of the immune system. Among several virulence factors, the lipopolysaccharide (LPS) of C. burnetii is one of the major factors involved in this immune hijacking because of its atypical composition and structure. Thus, the aim of this mini-review is to summarize the repressive effects of C. burnetii LPS on the antibacterial immunity of cells.

Safety and results of anti-PD1 combined with radiosurgery for the treatment of melanoma brain metastases

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Background: Anti-PD1 are now pivotal in the treatment of metastatic melanoma (MM). Some concerns have emerged regarding the risk/benefit ratio of their combination with stereotactic radiosurgery. Methods: Retrospective assessment of the interaction between Gamma-Knife radiosurgery (GKRS) and anti-PD1 in terms of toxicity and OS in mm patients (pts) with BM. Patients were included if they were under anti-PD1 (PRE) at time of GKRS, or if they had started anti-PD1 concomitantly with GKRS (CO), or had received anti-PD1 within 3 months after GKRS (POST). Results: Among 47 pts who received GKRS and anti-PD1 during their disease course, 35 fulfilled PRE or CO or POST criteria (anti PD1 1st line therapy in 10 pts and 2d or more in 25 pts). One pt died before radiological evaluation. GKRS targeted a single BM in 10 pts and multiple BMs in 24 (max 19 BMs). Out of the 128 BMs treated, 6 cases of increase of preexisting edema (4.7%) and 8 hemorrhages (6.25%) occurred in 12 pts, but only 5 events (5%) were regarded as Adverse Radiation effects (ARE), being symptomatic in 3 pts (8% of pts). One BM had to be resected because of the occurrence of a symptomatic hemorrhage with hemiparesis 9 month after treatment. Median follow- up from GKRS was 13.7 mths. Median overall survival (OS) from GKRS and 1st BM were 14.8 and 26.5 mths respectively, with 6 and 12 mths 0S rates from GKRS of 65.7% and 57%, respectively. Local failure was observed in 5 pt. Median time to new BM was 12.6 mths. There was no significant difference in outcomes in pts, depending on PRE, CO and POST conditions. Conclusions: In this series, the largest to date of pts with BMs treated by GKRS and anti-PD1,ARE were within the expected range and survival rates appear promising. Given the natural propensity of MM-BMs for bleeding and edema our data do not support an increased risk with the combination of GKRS and anti-PD1. Regarding the timing between anti-PD1 administration and GKRS our data do not support a higher efficacy or higher toxicity among the 3 following potential mechanisms: immuno- sensitization to radiation (PRE), immuno-radio direct synergy (CO) or radiosensitization to immunotherapy (POST).

Benefit of adjuvant chemotherapy with or without trastuzumab in pT1ab node-negative human epidermal growth factor receptor 2-positive breast carcinomas: results of a national multi-institutional study

PURPOSE

Benefit of adjuvant trastuzumab-based chemotherapy for node-positive and/or >1 cm human epidermal growth factor receptor 2-positive (HER2+) breast carcinomas has been clearly demonstrated in randomized clinical trials. Yet, evidence that adjuvant chemotherapy with or without trastuzumab is effective in pT1abN0 HER2+ tumors is still limited. The primary objective of this study was to investigate the impact of adjuvant chemotherapy ± trastuzumab on outcome in this subpopulation.

PATIENTS AND METHODS

A total of 356 cases of pT1abN0M0 HER2 + breast cancers were retrospectively identified from a large cohort of 22,334 patients, including 1248 HER2+ patients who underwent primary surgery at 17 French centers, between December 1994 and January 2014. The primary end point was disease-free survival (DFS). A multivariate Cox model was built, including adjuvant chemotherapy, tumor size, hormone receptor status, and Scarff Bloom Richardson (SBR) grade.

RESULTS

A total of 138 cases (39%) were treated with trastuzumab-based chemotherapy, 29 (8%) with chemotherapy alone, and 189 (53%) received neither trastuzumab nor chemotherapy. Adjuvant chemotherapy ± trastuzumab was associated with a significant DFS benefit (3-year 99 vs. 90%, and 5-year 96 vs. 84%, Hazard ratio, HR 0.26 [0.10-0.67]; p = 0.003, logrank test) which was maintained in multivariate analysis (HR 0.19 [0.07-0.52]; p = 0.001). Metastasis-free survival was also increased (HR 0.25 [0.07-0.86]; p = 0.018, logrank test) at 3-year (99 vs. 95%) and 5-year (98 vs. 89%) censoring. Exploratory subgroup analysis found DFS benefit to be significant in hormone receptor-negative, hormone receptor-positive, and pT1b tumors, but not in pT1a tumors.

CONCLUSIONS

Adjuvant chemotherapy ± trastuzumab is associated with a significantly reduced risk of recurrence in subcentimeter node-negative HER2+ breast cancers. Most of the benefit may be driven by pT1b tumors.

Macrophages in Invertebrates: From Insects and Crustaceans to Marine Bivalves

Macrophages are critical components of the antimicrobial response. The recent explosion of knowledge on the evolutionary, genetic, and biochemical aspects of the interaction between macrophages and microbes has renewed scientific interest in macrophages. The conservation of immune components or mechanisms between organisms during the evolutionary process allows us to elucidate antimicrobial mechanisms or discover new immune functions through the study of basal-branching organisms, such as invertebrates. As a result, immunity in non-vertebrates has attracted the attention of researchers in the last few decades. In this review, we summarize what is presently known about macrophage-like cells in various invertebrate species.

Prognostic and predictive values of diffusion and perfusion MRI in paediatric intracranial ependymomas in a large national study

OBJECTIVE

To assess the relative cerebral blood volume (rCBV) and apparent diffusion coefficient (ADC) derived, respectively, from perfusion and diffusion pre-operative MRI of intracranial ependymomas and their predictive and prognostic values.

METHODS

Pre-operative MRI and clinical data for intracranial ependymomas diagnosed between January 2000 and December 2013 were retrospectively retrieved from a web-based national database. MRI data included diffusion (62 patients) and perfusion (20 patients) MRI. Patient age, histopathological diagnosis, tumour location, ADC, relative ADC (rADC) and rCBV were considered as potential factors in a survival analysis. Survival rates were estimated using the Kaplan-Meier method. Univariate analyses were performed using the log-rank test to compare groups. We also performed a multivariate analysis, applying the Cox proportional hazards model.

RESULTS

ADC and rADC values within hypointense regions differed significantly between grades II and III (p = 0.01). The 75th percentile of ADC within hypointense regions and the 25th percentile of rCBV within non-enhancing lesions were prognostic of disease-free survival (p = 0.004, p = 0.05). A significant correlation was found between the 75th percentile of rCBV and the 25th percentile of rADC (p = 0.01) in enhancing regions of grade-III tumours.

CONCLUSION

Pre-operative rADC and rCBV could be used as prognostic factors for clinical outcome and to predict histological grade in paediatric ependymomas.

ADVANCES IN KNOWLEDGE

Prognostic value of diffusion and perfusion MRI in paediatric ependymoma was found and may play a role in the prognostic classification of patients in order to design more tailored treatment strategies.

[French organization of paediatric radiation treatment: Results of a survey conducted by the radiotherapy Committee of the French Society of Paediatric Cancers (SFCE)]

PURPOSE

Radiotherapy is a rare indication in paediatric oncology, with 800 to 900 children in treatment per year in France. Child cancers represent approximately 1% of cancers in France and half occur before the age of 5 years. Paediatric radiation requires appropriate tools, local, time and specific training. In France, in 2015, 18 centres are accredited by the French National Cancer Institute (INCa) for this activity.

MATERIAL AND METHODS

Survey conducted in February 2015 on the care of children (0 to 18 years) in radiotherapy departments in France. The survey was sent to the radiation oncologists involved in the 18 centres. The questions concerned the qualitative and quantitative aspect, medical and organizational aspects, and the involvement of assistant practitioners in the management of this activity.

RESULTS

Seventeen centres responded. In 2014, 889 children under 18 were treated in radiotherapy departments. These departments are working together with one to four paediatric oncology departments. Regarding access to general anaesthesia: three centres perform one to seven treatment(s) under anaesthesia per year, three centres eight to ten treatments under anaesthesia per year, three centres ten to 24 treatments under anaesthesia per year and nine centres out of 17 use hypnosis techniques. In terms of human resources, in 2015, 29 radiation therapists have a paediatric radiotherapy activity. Involvement of assistant practitioners is growing and specific training are desired. Regarding treatment preparation and delivery, 13 centres have specific paediatric contentions, 14 of 16 centres employ radiation intensity modulated if dosimetry is more satisfying with 11 regularly to the craniospinal irradiation. Radiotherapy on moving areas with respiratory gating or hypofractionation is under developed.

CONCLUSION

Paediatric radiation therapy is a specific activity requiring a dedicated management, both in human, organizational, medical and scientific aspects.

Abstract 2704: Radiotherapy and immunotherapy in cancer: A mathematical model

The rise of immunotherapy is a major breakthrough in oncology. Recently, the combination of radiotherapy with the blockade of immune checkpoint inhibitors such as the PD1-PDL1 axis or the CTLA4 pathway has shown a synergistic potential: in addition to the direct cell kill induced by irradiation, radiotherapy unleashes neoantigens that can further induce an anti-tumoral immune response. However, this immune response can be inhibited by the immunosuppressive nature of the tumor micro-environment (TME). Hence, radiotherapy combined with immune check-point inhibitors is a promising solution and is the subject of preclinical and clinical research. However, defining the most efficient scheduling between radiotherapy and immunotherapy is a crucial issue that cannot be properly addressed solely by empirical trial-and-error practices. Consequently, developing mathematical models that can describe the synergy between immune checkpoint inhibitors and radiotherapy is critical. Hence, we have built a pharmocodynamic model of the combination of radiotherapy with inhibitors of the PD1-PDL1 axis and/or the CTLA4 pathway. We describe a mathematical representation of how a growing tumor first elicits and then inhibits an anti-tumoral immune response. This anti-tumoral immune response is described by a primary and a secondary response. The primary immune response appears first and is down-regulated by the PD1-PDL1 axis, while the secondary immune response happens next and is down-regulated by the CTLA4 pathway. We describe the effects of irradiation by a slightly modified version of the Linear-Quadratic model. In particular, we explain the biphasic relationship between the size of a tumor and its immunogenicity, as measured by the abscopal immune response. The ability of the model to forecast pharmacodynamic endpoints was retrospectively validated by reproducing results from experimental studies investigating radiotherapy and immune checkpoint inhibitors. This model clarifies the issue of synchronisation of immunotherapy with radiotherapy and it also explains why the CTLA4 blockade often occurs with a delay. The model also explains why a sustained response to immunotherapy may or may not happen after treatment discontinuation. We believe that this mathematical model could be further used as a simulation tool to help decision-makers determine the optimal scheduling between radiotherapy and immunotherapy and could be a building block for the in-silico design of optimized multimodal strategies.

Citation Format: Raphael Serre, Xavier Muracciole, Joseph Ciccolini, Sebastien Benzekry, Dominique Barbolosi. Radiotherapy and immunotherapy in cancer: A mathematical model. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 2704.

An alternative parameter for early forecasting clinical response in NSCLC patients during radiotherapy: proof of concept study

OBJECTIVE

Positron emission tomography with (18)F fludeoxyglucose integrated with CT ((18)F-FDG PET/CT) is a recommended imaging procedure in the evaluation of non-small-cell lung cancers (NSCLCs). Radiochemotherapy (RCT) is a mainstay for treatment of locally advanced NSCLC, for which overall survival still remains poor. Early evaluation of treatment response may help in decision-making to complete radiotherapy (RT) or to switch to other treatment modalities. The present study aimed to evaluate the performance of new metabolic parameters based on a simplified kinetic analysis on a single time point (SKA-S)-derived mathematical method, as compared with standardized uptake value (SUV) measurement during RT.

METHODS

Four patients treated with RT or RCT for NSCLC were evaluated using (18)F-FDG PET/CT during RT and after treatment completion. Whole-body (18)F-FDG PET/CT was performed followed by four additional list-mode acquisitions centered over the target lesion. Response was evaluated at four times (i.e. PET1-PET4) by calculating standard SUV values and T80%, the time taken to reach 80% of (18)F-FDG metabolized fraction using a SKA-S-derived mathematical method.

RESULTS

Data from SUV and T80% calculations were found to be controversial. T80% was found to be more predictive of clinical outcome.

CONCLUSION

Although results from this pilot study should be further confirmed in a large prospective study, the data suggest that T80% is a promising metabolic biomarker for assessing early response to RT.

ADVANCES IN KNOWLEDGE

In this proof of concept study, we show that T80% defined from a mathematic model taking into account the net influx rate constant and vascular volume could be consider as a promising biomarker as compared with the maximum SUV.

Multicentre randomised phase II trial of gemcitabine+platinum, with or without trastuzumab, in advanced or metastatic urothelial carcinoma overexpressing Her2

AIM

To investigate the efficacy and safety of gemcitabine and platinum salt, with or without trastuzumab, in patients with locally advanced or metastatic urothelial carcinoma overexpressing Her2.

METHODS

The main eligibility criterion was Her2 overexpression on immunohistochemistry (IHC 2+ or 3+) of primary tumour tissue confirmed by fluorescence in situ hybridisation (FISH). Patients were randomised to Arm A: gemcitabine 1000mg/m(2) (days 1 and 8) plus either cisplatin (70mg/m(2)) or carboplatin (AUC=5) (day 1 every 3 weeks) or Arm B: added trastuzumab (8mg/kg loading dose, then 6 mg/kg every 21 days until progression). The primary end-point was progression-free survival (PFS).

RESULTS

Among 563 screened patients, 75 (13.3%) were Her2 positive (IHC 2+/3+ and FISH+) and 61 met all eligibility criteria (median age, 64 years; 54/61 males; 50/61 baseline ECOG-PS 0-1; 11 locally advanced and 50 metastatic). There was no significant difference between Arms A and B in median PFS (10.2 versus 8.2 months, respectively, p=0.689), objective response rate (65.5% versus 53.2%, p=0.39), and median overall survival (15.7 versus 14.1 months, respectively, p=0.684). In an exploratory analysis, trastuzumab-treated patients receiving cisplatin rather than carboplatin-based chemotherapy fared better (PFS: 10.6 versus 8.0; OS: 33.1 versus 9.5 months). Myelosuppression was the main grade 3/4 toxicity. A case of grade 3 cardiotoxicity and one death from febrile neutropenia occurred in arm B.

CONCLUSION

The unexpectedly low incidence of Her2 overexpression precluded the detection of a significant difference in efficacy on addition of trastuzumab to platinum-based chemotherapy with gemcitabine. However, the satisfactory tolerance of the combination warrants further studies, especially of the cisplatin-based combination, in well-defined patient subsets.

[Comparative study of radical prostatectomy versus external beam radiotherapy (75.6 Gy) combined with hormone therapy for prostate cancer of intermediate D'Amico risk classification]

INTRODUCTION

Thirty-three percent of the localized cancers belongs initially to the group of intermediate risk of D'Amico. The standard treatments validated by the French Association of Urology are the radical prostatectomy and the external beam radiotherapy.

OBJECTIVES

We retrospectively compared the carcinologic results of the radical prostatectomy±adjuvant treatment (RP) and the external beam radiotherapy combining high dose (75.6 Gy) and short hormonotherapy (RH), in the treatment of intermediate risk prostate cancer. The series consisted of 143 patients treated between 2000 and 2006 in the department of Urology and Kidney transplantation of the Conception Hospital, Marseilles. The main assessment criteria was the survival without biological recurrence (SBR).

RESULTS

The median follow-up was 90 months [59-51]. The 5 years and 8 years SBR were 85% and 73% in the RH group, versus 74% and 65% with RP (P=0.196). There was a significant difference between the series: on the age of diagnosis (63.9 versus 73.3 years, P<0.001), the Charlson score of comorbidity (2 versus 3, P<0.001) and the number of intermediate criteria per patients (one intermediate criteria: RP 74% versus 57%, P<0.01).

CONCLUSION

According to our study, there was no superiority of the radical prostatectomy±adjuvant treatment or the external radiotherapy combining high dose and concomitant short hormonotherapy on the survival without biological recurrence at 5 and 8 years. Many studies confirm that a concomitant hormonotherapy increases the carcinologic control, even with a high rate external beam radiotherapy.