Prostate specific antigen bounce after simultaneous irradiation for prostate cancer: The relationship to patient age

Purpose: We report on the relationship of patient age to prostate specific antigen (PSA) bounce after brachytherapy for prostate cancer. Materials and Methods: From 1992 to 1997, 1,011 consecutive men with stage T1-T2NxM0 prostate cancer were treated with simultaneous irradiation, transperineal prostate I-125 implant followed by external beam irradiation. No patients received neoadjuvant hormones. There were 251, 491 and 269 men 60 years old or younger, 61 to 70 and 71 or older, respectively, at implant. PSA bounce is defined by a postirradiation PSA increase of 0.1 ng/ml or more above the level before bounce followed by a decrease to or below that level. Disease freedom is defined by a PSA cut point of 0.2 ng/ml. Median followup is 6 years (range 3 months to 10 years). Results: The frequency of PSA bounce according to age 60 or younger, 61 to 70 and 71 or older is 57%, 41% and 26%, respectively, a significant difference (p <0.000), average time to bounce onset is 19, 20 and 25 months for these 3 age groups, respectively, a significant difference (p = 0.002), and average bounce duration is 11, 8 and 8 months, respectively, a significant difference (p <0.000). On multivariate analysis of age, pretreatment PSA, Gleason score, stage, implant dose, prostate volume, diabetes and race, only age is significantly associated with PSA bounce (p <0.0001). After adjusting for the inherent bias caused by PSA bounce, there is no significant difference in disease-free survival between men with and without bounce. Conclusions: Young men with prostate cancer treated with brachytherapy have a significantly higher frequency, earlier onset and longer duration of PSA bounce than older men.