Prostate-specific antigen bounce after curative brachytherapy for early-stage prostate cancer: A study of 274 African-Caribbean patients.

Abstract

Prostate cancer incidence in the African-Caribbean population ranks among the highest worldwide. We aim to evaluate the prostate-specific antigen (PSA) kinetics after brachytherapy, which so far remains unknown in this population. From 2005 to 2013, 371 patients received (125)I brachytherapy of 145 Gy for early-stage prostate cancer. Eligibility criteria were cTNM ≤T2c, Gleason score ≤7, and initial PSA ≤15 ng/mL. Pretreatment androgen deprivation therapy was allowed. PSA bounce was defined as an increase of ≥0.4 ng/mL, lasting ≥6 months, followed by a decrease without any anticancer therapy. We examined PSA kinetics during followup. For the 274 patients with at least 24 months followup, median age was 62 years old (range, 45-76). Initial PSA was <10 ng/mL in 244 and 10-15 ng/mL in 30 patients; 40 received androgen deprivation therapy. With a median followup of 50 months (range, 24-125), PSA declined continuously in 168 (61%) patients, bounced in 87 (31%), and initially declined and then rose in 22 (8%) patients. Among these latter patients, 18 presented clinical recurrence. Mean bounce intensity was 2.0 ng/mL (median, 1.2; range, 0.4-12.4). Bounces occurred in average 12 months after brachytherapy. Patients with bounce were significantly younger: mean age 59 vs. 63 years old in patients without bounce, p <0.001. Bounce was also significantly associated with the immediate post-brachytherapy PSA, mean 4.0 among bounce cases vs. 2.9 among non-bounce cases, p < 0.001. Bounce was not associated with recurrence. PSA bounce in our African-Caribbean population seemed earlier and was more intense than described in other populations. Early increase of PSA should not be ascribed to treatment failure.