Because patients with prostate-specific antigen (PSA) bounce do not experience biochemical recurrence (BCR) until PSA bounce occurs, the period until PSA bounce ends can be considered the so-called lead-time bias. Therefore, we evaluated differences in BCR-free rate in prostate cancer patients who were BCR-free 4 years after 125I-brachytherapy alone. Furthermore, we evaluated predictors for PSA bounce and the correlation between testosterone and PSA bounce.
From 2004 to 2012, 256 patients with prostate adenocarcinoma underwent 125I-brachytherapy alone. PSA and testosterone levels were monitored prior to 125I-brachytherapy, at 1, 3, 6, 12, 18, 24, 30, 36, 42, 48, 54 and 60 months after 125I-brachytherapy and yearly after 5-year follow-up. PSA bounce was defined as ≥0.2 ng/ml increase above the interval PSA nadir, followed by a decrease to nadir or below.
BCR-free rate in patients with PSA bounce (100% 7-year BCR-free rate) was significantly better (P < 0.044) than that in patients without PSA bounce (95.7% 7-year BCR-free rate) in patients who were BCR-free 4 years after 125I-brachytherapy alone (n = 223). Age was the only predictor (odds ratio: 0.93, 95% confidence interval: 0.88-0.98, P = 0.004) for PSA bounce (n = 177). The testosterone level at PSA bounce was significantly higher (P = 0.036) than that at nadir before PSA bounce (87 cases).
Patients with PSA bounce had good BCR-free rate even in patients who were BCR-free 4 years after 125I-brachytherapy alone. Testosterone levels were higher at PSA bounce; increased testosterone levels may be a cause of PSA bounce.
Japanese journal of clinical oncology. 2019 Oct 28 [Epub ahead of print]
Yasushi Nakai, Nobumichi Tanaka, Isao Asakawa, Satoshi Anai, Makito Miyake, Yosuke Morizawa, Shunta Hori, Takuya Owari, Tomomi Fujii, Kaori Yamaki, Masatoshi Hasegawa, Kiyohide Fujimoto
Department of Urology, Nara Medical University, Nara, Japan., Department of Radiation Oncology, Nara Medical University, Nara, Japan., Department of Diagnostic Pathology, Nara Medical University, Nara, Japan.