Prostate-specific antigen bounce in patients treated before 60 years old by iodine 125 brachytherapy for prostate cancer is frequent and not a prognostic factor.

PURPOSE: The only prognostic factor of prostate-specific antigen (PSA) bounce in prostate cancer found in several studies is young age but has never been specifically studied in this subset of patients for long-term results. Bounce characteristics, histological, clinical, and dosimetric data in young patients were analyzed, as well as their impact on toxicity and survival.

MATERIAL AND METHODS: This retrospective study included patients aged ≤60 years treated with exclusive iodine 125 brachytherapy with low or intermediary prostate adenocarcinoma during 1999-2014. Exclusion criteria were a follow-up of ≤24 months. PSA bounce was defined as a ≥0.2-ng/mL increase above the interval PSA nadir, followed by a decrease to nadir or below.

RESULTS: This study analyzed 179 patients. Median age was 56 years (46-59 years). The median follow-up was 79 months (54; 123). The bounce incidence was 56.8% (49.6%; 64.2%) at 5 years, inversely proportional to positive/total biopsies ratio (HR 0.98, 95% CI [0.97, 0.99]). Incidence of biochemical failure was 1.2%, 95% CI (0.3%; 4.7%), at 5 years with no difference between the bounce and no-bounce group (HR 0.96, 95% CI [0.25; 3.58]). Bounce is an unfavorable prognostic factor for grade two and three urinary toxicities 6.67 (4.14; 10.76) (p < 0.001).

CONCLUSIONS: PSA bounce is common in young people after brachytherapy. It should be monitored without starting an inadequate and sometimes invasive relapse checkup or a relapse treatment.