In men with nonmetastatic castration-resistant prostate cancer (M0CRPC), the prostate-specific antigen (PSA) doubling time and the time to castration resistance (TTCRPC) predict cancer-specific survival (CSS), a recent study has found.
A team of researchers conducted a retrospective cohort analysis of 82 M0CRPC patients (median age 76 years), who had a median PSA value of 2.84 ng/mL at the time of CRCP diagnosis. Over a median follow-up time of 38 months, 21 patients died of prostate cancer, resulting in 3- and 5-year CSS rates of 79.5 percent and 64.9 percent, respectively.
Unadjusted analysis identified PSA doubling time ≤3 months and TTCRPC ≤12 months as potential risk factors for CSS. TTCRPC was measured from the start of androgen deprivation therapy.
Multivariate adjustment of the Cox proportional hazard model confirmed the significance of both factors: TTCRPC ≤12 months (hazard ratio [HR], 3.714, 95 percent confidence interval [CI], 1.233–11.19; p=0.0197) and PSADT ≤3 months (HR, 3.005, 95 percent CI, 1.157–7.809; p=0.0239).
Moreover, patients who were deemed high-risk based on the presence of both these factors saw a more than fourfold increase in CSS than low-risk comparators (HR, 4.416, 95 percent CI, 1.701–11.47).
“These patients may be candidates for novel imaging techniques such as prostate-specific membrane antigen positron emission tomography, and early treatment may be beneficial to prolong the survival of these patients,” the researchers said. Larger prospective studies are needed to validate the present findings.