Full-coverage radiotherapy for prostate cancer patients with oligometastases

Abstract

Abstract Objective The role of radiotherapy in the treatment of oligometastatic prostate cancer (omPCa) remains unclear. This study aimed to investigate the potential survival benefit of full-coverage radiotherapy in patients with omPCa.Methods A retrospective analysis was conducted on patients with omPCa who received full-coverage radiotherapy between July 2012 and June 2022. Full-coverage radiotherapy was defined as radiotherapy to all lesions, including the primary site and metastatic lesions. Overall survival (OS) was the primary endpoint, and biochemical progression-free survival (bPFS) and radiological progression-free survival (rPFS) were the secondary endpoint. The Kaplan-Meier method was used to estimate univariate analysis, and the log-rank test was used to conduct multivariate analysis.Results A total of 33 patients, including 31 de novo oligometastatic hormone-sensitive prostate cancer (omHSPC) patients and 2 oligometastatic castration-resistant prostate cancer (omCRPC) patients, were enrolled in the study. The median follow-up was 38.8 months (range: 4.2–70.6 months). The median OS was 127.7 months (95% CI: not reach- not reach months), and the survival rates at 2, 3, and 5 years were 100%, 95.7%, and 81.2%, respectively. The median bPFS was 58.9 months (95% CI: 47.7–70.1 months) and the median rPFS is 55.3 months (95% CI: 39.9–70.8 months). Transurethral resection of the prostate (TURP) prior to radiotherapy (p = 0.04), presence of symptoms related to the lesions (p = 0.003), and the pre-radiotherapy status of castration-resistant prostate cancer (CRPC) (p = 0.006) were associated with poorer survival. Multivariate analysis showed that external beam radiation therapy (EBRT) synchronized with androgen deprivation therapy (ADT) or chemotherapy (HR = 9.871, 95%CI (1.540-63.263), p = 0.016), non-CRPC status before radiotherapy(HR = 52.555, 95%CI (5.776-478.226), p = 0.000), and prostate-specific antigen(PSA) levels more than 1 ng/ml before radiotherapy (HR = 7.596, 95%CI (1.498–38.192), p = 0.014) may be associated with longer rPFS. The coexistence of lymph node and bone metastases is associated with a higher risk of biochemical recurrence (HR = 8.823, 95%CI (1.419–54.848), p = 0.02). The occurrence of acute adverse reactions of Grade 3 or higher was not observed, while the incidence of chronic adverse reactions of Grade 3 was 3.03%.Conclusion Full-coverage radiotherapy with an optimistic bPFS and rPFS may improve the OS of patients with oligometastatic prostate cancer.