Although the relationship between prostate-specific antigen (PSA) kinetics and prognosis in metastatic castration-sensitive prostate cancer (mCSPC) cases has been examined in a pivotal randomized control trial and real-world studies, there are no known reports regarding which PSA kinetic parameter is the most valuable surrogate marker for indicating survival outcome. The present retrospective multicenter study investigated the relationship of absolute PSA value and relative PSA response rate with the prognosis of mCSPC patients in real-world clinical settings.
Among patients diagnosed with mCSPC, 114 who received androgen receptor signaling inhibitors (ARSI) between June 2019 and September 2024 were included. Outcome measures included achievement of absolute PSA value and relative PSA response at 3 months following initiation of first-line ARSI treatment, survival outcome.
The median follow-up period was 20 months. The results were insufficient to demonstrate a difference in terms of Overall survival (OS) stratified by achievement of PSA ≤ 0.2 ng/mL (hazard ratio [HR] 0.44, 95% confidence interval [CI] 0.16-1.23; p = 0.119). Nevertheless, patients who achieved a ≥ 99% decline in PSA showed significantly better OS as compared with those who did not (HR 0.27, 95% CI 0.10-0.74; p = 0.011). After adjustment for liver metastasis and EOD ≥ 3, achievement of PSA decline ≥ 99% was associated with better OS (HR = 0.17, 95% CI 0.05-0.62; p = 0.007).
These results show the usefulness of PSA decline ≥ 99% as a prognostic marker for mCSPC patients.
International journal of urology : official journal of the Japanese Urological Association. 2026 Jun [Epub]
Toru Suzuki, Takahiro Fukuda, Kosuke Nishizaki, Koji Fukui, Shimpei Yoshioka, Yohei Kaizuka, Seiji Nagasawa, Yoshikazu Togo, Yoshitaka Motoki, Wataru Tanaka, Yasuo Ueda
Department of Urology, Takarazuka City Hospital, Takarazuka, Japan., Department of Urology, Kawanishi City Medical Center, Kawanishi, Japan., Department of Urology, Nishinomiya Municipal Central Hospital, Nishinomiya, Japan.