Impact of Time to Castration Resistance on Cytoreductive Radiotherapy in Metastatic Castration-Resistant Prostate Cancer

Abstract

BackgroundThe role of local radiotherapy in metastatic castration-resistant prostate cancer (mCRPC) remains undefined. This study aimed to identify the value of local radiotherapy and potential candidates for mCRPC.MethodsA total of 215 patients with mCRPC treated with or without cytoreductive radiotherapy (CRT) between June 2011 and February 2019 were analyzed. Overall survival (OS) was calculated from the onset of mCRPC. The receiver-operating characteristic (ROC) curve was used to find the cutoff point for time to castration resistance (TCR).ResultsOne-hundred and fifty-five (72.1%) patients received abiraterone after mCRPC, and 54 (25.1%) patients received CRT. The median TCR was 14.9 months. After a median follow-up of 31.7 months, the median OS was 33.3 months. The Eastern Cooperative Oncology Group (ECOG) performance scores 0–1, oligometastases, abiraterone after mCRPC, CRT, and TCR ≥9 months were independent prognostic factors for better OS. Stratified analyses showed improved survival when CRT was applied to patients treated with abiraterone (HR 0.44; 95% CI 0.23–0.83; P = 0.012) and TCR ≥9 months (HR 0.39; 95% CI 0.21–0.74; P = 0.004). The percentage of PSA response after radiotherapy was higher in patients with TCR ≥9 months compared to those with TCR <9 months. No grade 3 or worse adverse events after radiotherapy were reported.ConclusionsECOG performance score, oligometastases, abiraterone application, TCR and CRT were independent prognostic factors for OS in patients with mCRPC. Patients with a short duration of response to primary androgen deprivation therapy were less likely to benefit from CRT.

Metastases-directed radiotherapy in castration resistant oligo metastatic prostate cancer: A multicentric retrospective study from the French group COLib

“…Furthermore, our study identified no significant correlation between the International Society of Urological Pathology (ISUP) grade at diagnosis, the duration of the hormone-sensitivity phase, the PSA level at the start of MDRT, and the subsequent progression-free survival. This observation does not align with suggestions from Mai’s cohort that patients who experience a brief hormone-sensitive phase may derive less benefit from cytoreductive radiotherapy during the castration-resistant phase of their disease [22] . However, only 28 % of patients had oligometastatic disease in this cohort.…”

Expression and prognostic significance of vascular endothelial growth factor‐A (VEGF‐A) and its receptor in canine prostate cancer

“…However, a set of tumors becomes resistant to the androgen deprivation treatment, which poses a serious therapeutic challenge 23 . These castration‐resistant prostate cancers (CRPC) exhibit high rates of metastasis and poor outcomes in the patients with PC 24,25 . They are uniquely positive for the AR but lack the sensitivity to hormone stimulation.…”