Despite multimodality treatments including neurosurgery, radiotherapy and chemotherapy, glioblastoma (GBM) prognosis remains poor. GBM is classically considered as a radioresistant tumor, because of its high local recurrence rate, inside the irradiation field. The development of new radiosensitizer is crucial to improve the patient outcomes. Pre-clinical data showed that Poly (ADP-ribose) polymerase inhibitors (PARPi) could be considered as a promising class of radiosensitizer. The aim of this study is to evaluate Olaparib, a PARPi, as radiosensitizing agent, combined with the Stupp protocol, namely temozolomide (TMZ) and intensity modulated radiotherapy (IMRT) in first line treatment of partially or non-resected GBM. The OLA-TMZ-RTE-01 study is a multicenter non-randomized phase I/IIa trial including unresectable or partially resectable GBM patients, from 18 to 70 years old. A two-step dose-escalation phase I design will first determine the recommended phase 2 dose (RP2D) of olaparib, delivered concomitantly with TMZ plus conventional irradiation for 6 weeks and as single agent for 4 weeks (radiotherapy period), and second, the RP2D of olaparib combined with adjuvant TMZ (maintenance period). Phase IIa will assess the 18-month overall survival (OS) of this combination. In both phase I and IIa separately considered, the progression-free survival, the objective response rate, the neurocognitive functions of patients, emotional disorders among caregivers, the survival without toxicity, degradation nor progression, the complications onset and the morphologic and functional MRI (magnetic resonance imaging) parameters will be also assessed as secondary objectives. Ancillary objectives will explore alteration of the DNA repair pathways on biopsy tumor, proton magnetic resonance spectroscopy parameters to differentiate tumor relapse and radionecrosis, and an expanded cognition evaluation. Up to 79 patients will be enrolled: 30 patients in the phase I and 49 patients in the phase IIa. Combining PARP inhibitors, such as olaparib, with radiotherapy and chemotherapy in GBM may improve survival outcomes, while sparing healthy tissue and preserving neurocognitive function, given the replication-dependent efficacy of olaparib, and the increased PARP expression in GBM as compared to non-neoplastic brain tissue. Ancillary studies will help to identify genetic biomarkers predictive of PARPi efficacy as radiosensitizer. NCT03212742 , registered June, 7, 2017. Protocol version: Version 2.2 dated from 2017/08/18.

Immunotherapy has revolutionized the practice of oncology, improving survival in certain groups of patients with cancer. Immunotherapy can synergize with radiation therapy, increase locoregional control, and have abscopal effects. Combining it with other treatments, such as targeted therapies, is a promising means of improving the efficacy of immunotherapy. Because the value of immunotherapy is amplified with the expression of tumor antigens, coupling poly(ADP-ribose) polymerase (PARP) inhibitors and immunotherapy might be a promising treatment for cancer. Further, PARP inhibitors (PARPis) are being combined with radiation therapy to inhibit DNA repair functions, thus enhancing the effects of radiation; this association might interact with the antitumor immune response. Cytotoxic T lymphocytes are central to the antitumor immune response. PARP inhibitors and ionizing radiation can enhance the infiltration of cytotoxic T lymphocytes into the tumor bed, but they can also enhance PD-1/PDL-1 expression. Thus, the addition of immune checkpoint inhibitors with PARP inhibitors and/or ionizing radiation could counterbalance such immunosuppressive effects. With the present review article, we proposed to evaluate some of these associated therapies, and we explored the biological mechanisms and medical benefits of the potential combination of radiation therapy, immunotherapy, and PARP inhibitors.

Until 50% of patients with renal cancer or melanoma, develop brain metastases during the course of their disease. Stereotactic radiotherapy has become a standard of care for patients with a limited number of brain metastases. Given the radioresistant nature of melanoma and renal cancer, optimization of the fractionation of stereotactic radiotherapy is needed. The purpose of this retrospective study was to elucidate if hypofractionated stereotactic radiotherapy (HFSRT) impacts local control of brain metastases from radioresistant tumors such as melanoma and renal cancer, in comparison with radiosurgery (SRS). Between 2012 and 2016, 193 metastases, smaller than 3 cm, from patients suffering from radioresistant primaries (melanoma and renal cancer) were treated with HFSRT or SRS. The primary outcome was local progression free survival (LPFS) at 6, 12 and 18 months. Overall survival (OS) and cerebral progression free survival (CPFS) were secondary outcomes, and were evaluated per patient. Objective response rate and radionecrosis incidence were also reported. The statistical analysis included a supplementary propensity score analysis to deal with bias induced by non-randomized data. After a median follow-up of 7.4 months, LPFS rates at 6, 12 and 18 months for the whole population were 83, 74 and 70%, respectively. With respect to fractionation, LPFS rates at 6, 12 and 18 months were 89, 79 and 73% for the SRS group and 80, 72 and 68% for the HFSRT group. The fractionation schedule was not statistically associated with LPFS (HR = 1.39, CI95% [0.65–2.96], p = 0.38). Time from planning MRI to first irradiation session longer than 14 days was associated with a poorer local control rate. Over this time, LPFS at 12 months was reduced from 86 to 70% (p = 0.009). Radionecrosis occurred in 7.1% for HFSRT treated metastases to 9.6% to SRS treated metastases, without any difference according to fractionation (p = 0.55). The median OS was 9.6 months. Six, 12 and 18 months CPFS rates were 54, 24 and 17%, respectively. Fractionation does not decrease LPFS. Even for small radioresistant brain metastases (< 3 cm), HFSRT, with 3 or 6 fractions, leads to an excellent local control rate of 72% at 1 year with a rate of 7.1% of radionecrosis. HFSRT is a safe and efficient alternative treatment to SRS.

Purpose: Radiochemotherapy remains the mainstay of glioblastoma (GBM) first-line treatment after extended surgery, but the prognosis is still poor. PARP inhibitors like olaparib may improve GBM outcomes. We implemented a phase I to IIa trial to assess the safety and efficacy of olaparib combined with standard radiochemotherapy as a first-line treatment in patients with unresected GBM. We herein present results of phase I. Patients and Methods: Based on the Stupp regimen, two sequential dose escalations of olaparib were performed to distinguish the radiotherapy period and the maintenance period for assessing the MTD of olaparib separately for each treatment period. Dose escalations were performed by a Time-to-Event Continual Reassessment Method. Results: A total of 30 patients were enrolled: 20 (66.7%) men, median age 59 years (range, 25–70), and 12 patients (42.9%) with Eastern Cooperative Oncology Group performance status of 0. Among them, 16 and 11 patients were assessable for determining MTD in each period. Hematologic dose-limiting toxicities were experienced by four and one patients in each sequential dose escalation, respectively. The MTD was olaparib 100 mg twice daily for 3 days a week in concomitant during both the radiochemotherapy and maintenance periods of the standard treatment. The median progression-free and overall survival were 6.2 and 19.8 months, respectively. The 2-year survival rate was 36.7% (22.9–58.7). Conclusions: Intermittent dosing of olaparib at radiosensitizing concentrations in concomitant with the Stupp protocol has an acceptable safety profile with promising outcomes in patients with unresectable GBM. Further efficacy determination is ongoing in the phase IIa step.

Objective: To evaluate the incidence of the abscopal response (AR) in patients with metastatic melanoma requiring palliative radiotherapy (RT). Patients and methods: Patients treated for metastatic melanoma between January 1998 and February 2020 in four oncology departments were screened. Patients with progression under immune checkpoint inhibitors or without ongoing systemic treatment, and requiring palliative RT were considered. The AR was defined as an objective response according to RECIST and/or iRECIST for at least one non-irradiated metastasis at distance (≥10 cm) from the irradiated lesion. Primary endpoint was the rate of AR. Secondary endpoints were overall survival (OS), progression-free survival (PFS), local control (LC) of the irradiated lesion, and toxicity as assessed by CTCAE v5. Results: Over the period considered, 118 patients were included and analyzed. Fifteen patients (12.7%) had an AR. With a median follow-up of 7.7 months (range, 0.2–242.2), median OS and PFS after RT were significantly longer in patients with an AR compared to those without: 28 vs. 6.6 months (p < 0.01) and not reached vs. 3.2 months, respectively. No grade ≥2 toxicity was reported. Patients who developed an AR were more likely to be treated with immunotherapy (93.3% vs. 55.9%, p = 0.02). In multivariate analysis, they had a higher number of irradiated metastases treated concomitantly (HR = 16.9, p < 0.01) and a higher rate of mild infections during RT (HR = 403.5, p < 0.01). Conclusions: AR in metastatic melanoma seems to be highly prognostic of overall survival, although it is a rare phenomenon. It may be promoted by multiple concomitant treatments with RT and immunotherapy and by acute inflammatory events such as infection.

Survival of childhood, adolescent and young adult (CAYA) cancers has increased with progress in the management of the treatments and has reached more than 80% at 5 years. Nevertheless, these survivors are at great risk of second cancers and non-malignant co-morbidities in later life. DeNaCaPST is a non-interventional study whose aim is to organize a national screening for thyroid cancer and breast cancer in survivors of CAYA cancers. It will study the compliance with international recommendations, with the aim, regarding a breast screening programme, of offering for every woman living in France, at equal risk, an equal screening. DeNaCaPST trial is coordinated by the INSERM 1018 unit in cooperation with the LEA (French Childhood Cancer Survivor Study for Leukaemia) study’s coordinators, the long term follow up committee and the paediatric radiation committee of the SFCE (French Society of Childhood Cancers). A total of 35 centres spread across metropolitan France and la Reunion will participate. FCCSS (French Childhood Cancer Survivor Study), LEA and central registry will be interrogated to identify eligible patients. To participate, centers agreed to perform a complete “long-term follow-up consultations” according to good clinical practice and the guidelines of the SFCE (French Society of Children Cancers). As survival has greatly improved in childhood cancers, detection of therapy-related malignancies has become a priority even if new radiation techniques will lead to better protection for organs at risk. International guidelines have been put in place because of the evidence for increased lifetime risk of breast and thyroid cancer. DeNaCaPST is based on these international recommendations but it is important to recognize that they are based on expert consensus opinion and are supported by neither nonrandomized observational studies nor prospective randomized trials in this specific population. Over-diagnosis is a phenomenon inherent in any screening program and therefore such programs must be evaluated.