Randomized phase II trial in prostate cancer with hormone-sensitive OligometaSTatic relapse: Combining stereotactic ablative radiotherapy and durvalumab (POSTCARD GETUG P13): Study protocol.

Background: As in other solid tumors, increasing evidence indicates that patients diagnosed with a limited number of prostate cancer metastases, so-called oligometastases, have a better prognosis than patients with extensive metastatic disease. Stereotactic body radiotherapy (SBRT) is now considered an option in this population.Programmed death-1 (PD-1) and its ligands (PD-L1) are targeted by immune checkpoint inhibitors. Preclinical studies have shown that the tumor immune microenvironment changes when combining radiotherapy with immunotherapy, especially with hypofractionated radiotherapy.The oligometastatic setting appears to be the most relevant clinical situation for evaluating the immune response generated by radiotherapy and immune checkpoint inhibitors in patients with an intact immune system.We hypothesize that durvalumab will enhance the immune response following SBRT targeting oligometastatic lesions. Our purpose is to demonstrate, via a randomized 2:1 phase II trial, that SBRT (3 fractions) with durvalumab in oligometastatic hormone-sensitive prostate cancer patients would improve progression-free survival in patients with prostate cancer with up to 5 metastases compared to patients who exclusively received SBRT. Methods: This is a multicentric randomized phase II study in French academic hospitals. Patients with prostate cancer and up to 5 metastases (lymph node and/or bone) were randomized into a 2:1 ratio between Arm A (experimental group), corresponding to durvalumab and SBRT to the metastases, and Arm B (control group), corresponding to SBRT alone to the metastases. The study aims to accrue a total of 96 patients within 3 years. The primary endpoint is two-year progression-free survival and secondary endpoints include androgen deprivation therapy-free survival, quality of life, toxicity, prostate cancer specific survival, overall survival, and immune response. Discussion: The expected benefit for the patients in the experimental arm is longer life expectancy with acceptable toxicity. We also expect our study to provide data for better understanding the synergy between immunotherapy and radiotherapy in oligometastatic prostate cancer.

Retrorectal Mucinous Adenocarcinoma Arising from a Tailgut Cyst: A Case Report.

We report the case of a 57-year-old woman who presented with local invasion of the anal canal by mucinous adenocarcinoma, the malignant transformation of a long-term preexisting retrorectal tailgut cyst. This progression is infrequent and justifies preemptive surgical treatment of retrorectal cysts.

Targeting Stereotactic Body Radiotherapy on Metabolic PET- and Immuno-PET-Positive Vertebral Metastases.

(1) Background: Stereotactic body radiotherapy (SBRT) for vertebral metastases (VM) allows the delivery of high radiation doses to tumors while sparing the spinal cord. We report a new approach to clinical target volume (CTV) delineation based on anti-carcinoembryonic antigen (CEA) positron emission tomography (pretargeted immuno-PET; "iPET") in patients with metastatic breast cancer (BC) or medullary thyroid cancer (MTC). (2) Methods: All patients underwent iPET, spine magnetic resonance imaging (MRI), and positron emission tomography-computed tomography (PET-CT) using 18F-deoxyglucose (FDG) for BC or 18F-dihydroxy-phenylalanine (F-DOPA) for MTC. Vertebrae locations and vertebral segments of lesions were recorded and the impact on CTV delineation was evaluated. (3) Results: Forty-six VM eligible for SBRT following iPET were evaluated in eight patients (five BC, three MTC). Eighty-one vertebral segments were detected using MRI, 26 with FDG or F-DOPA PET/CT, and 70 using iPET. iPET was able to detect more lesions than MRI for vertebral bodies (44 vs. 34). iPET-based delineation modified MRI-based CTV in 70% (32/46) of cases. (4) Conclusion: iPET allows a precise mapping of affected VM segments, and adds complementary information to MRI in the definition of candidate volumes for VM SBRT. iPET may facilitate determining target volumes for treatment with stereotactic body radiotherapy in metastatic vertebral disease.

[Oligorecurrent prostate cancer: current management and perspectives]. / Prise en charge des rechutes oligométastatiques des cancers de prostate : actualités et perspectives.

Oligometastatic prostate cancer (PCa) is an intense area of research thanks to the development of novel PET tracers such as 18F-choline or 68Ga-PSMA. Several retrospective studies in patients with hormone-sensitive oligorecurrent PCa (usually up to 5 metastases with a controlled primary tumor) showed PSA response and a low toxicity profile of metastasis-directed therapies (MDT) such as Stereotactic Body Radiation Therapy (SBRT) or salvage lymph node dissection. More recently, randomized phase 2 studies showed that SBRT can delay the introduction of androgen deprivation, decrease biochemical relapses and increase overall survival. Regarding oligoprogressive metastatic castration-resistant PCa, limited data is however available. Based on these studies the European Association of Urology and the American Society of Radiotherapy EAU now recommend using MDT instead of observation. Several studies are undergoing in France and worldwide in order to confirm the exact role of MDT.