PSA doubling time (PSADT) can predict oncologic and survival outcomes among men who receive brachytherapy for localized prostate cancer (PCa), new study findings suggest.
Results showed that shorter PSADT is associated with worse disease-specific, metastasis-free, and overall survival.
“Given the variable trajectory of metastatic and recurrent PCa, strong prognostic factors such as PSADT may be able to select a group of patients who benefit from earlier or escalated systemic therapies such as androgen deprivation or cytotoxic chemotherapy,” Lucas Resende Salgado, MD, of Mount Sinai Hospital in New York, and colleagues wrote in a paper published online ahead of print in Brachytherapy.
Dr Resende Salgado’s group studied 2771 patients treated for localized PCa with low-dose-rate brachytherapy. Of the 251 patients who had biochemical failure, 115 (45.8%), 58 (23.1%), and 78 (31.15) had a PSADT of less than 6, 6–12, and more than 12 months, respectively. Patients had a median follow-up of 7.8 years.
Men with a PSADT of 6, 6–12 and more than 12 months had 15-year actuarial disease-specific survival (DSS) rates of 35%, 69%, and 93%, respectively, according to the investigators. The 15-year rates of actuarial freedom from distant metastasis (DM) were 37.5%, 72%, and 84%, respectively, and the 15-year actuarial overall survival (OS) rates were 10%, 45%, and 63%, respectively.
Men who did not have biochemical failure had 15-year rates actuarial DSS, freedom from DM, and OS of 100%, 99%, and 56%, respectively.
On multivariable analysis, PSADT was significantly associated with DSS and DM but not OS, which appears to be impacted mainly by initial age at diagnosis and disease stage, the investigators reported.
Resende Salgado L, Rhome R, Oh W, et al. Prostate-specific antigen doubling time is a significant predictor of overall and disease-free survival in patients with prostate adenocarcinoma treated with brachytherapy. Brachytherapy. 2018; published online ahead of print.