Radiotherapy of Oligoprogressive Lesions in Castration-Resistant Prostate Cancer: Impact on Second-Generation Hormone Therapy

Background: The therapeutic standard for oligoprogressive prostate cancer resistant to castration is second-generation hormone therapy. This systemic treatment is expensive. There are oligoprogressive lesions accessible to radiotherapy. Objectives: To study the impact of radiotherapy of oligoprogressive lesions on the implementation of second generation hormone therapy. Patients and Methods: A retrospective study from 2012 to 2020 was carried out. All patients with oligoprogressive prostate cancer who had received radiotherapy on one or more lesions in progression were collated. Survival was calculated using the Kaplan-Meier method. Results: 8 patients were treated with stereotactic and conformational radiotherapy between August 2012 and August 2020 in the context of oligoprogressive prostate cancer resistant to castration. The median age at diagnosis of oligoprogression was 73 years with a median PSA level of 3.11 ng/ml. Nine lesions were diagnosed with PET scan PSMA. All the lesions were treated by radiotherapy with different regimens. After a median follow-up of 12.5 months, 7 patients showed a biochemical response to treatment with a median decrease in PSA of 67%. The median survival without clinical or biochemical progression was 7 months. The median survival without the need for further systemic treatment was 9 months. During the follow-up period, six patients received second-generation hormone therapy to treat their relapse, and the other two showed no clinical or biochemical relapse. Conclusion: Radiotherapy may be an alternative to delay the introduction of difficult-to-access second-generation hormone therapy in developing countries. A prospective study could validate this therapeutic approach.