Cumulative risk of developing prostate cancer in men with low (≤2.0 ng/mL) prostate‐specific antigen levels: A population‐based screening cohort study in Japan. (23rd December 2013) - Sawada, Kiyoshi
Abstract Objectives To investigate the natural history of men with low levels of baseline prostate‐specific antigen in terms of risk of increased prostate‐specific antigen, developing prostate cancer and also the likelihood of detecting clinically insignificant cancer in population‐based screening. Methods A total of 10 653 men aged between 55 and 68 years with baseline prostate‐specific antigen levels of 2.0 ng/mL or lower screened annually were enrolled. The cumulative risks of increased prostate‐specific antigen and developing cancer were investigated. The relationships of baseline prostate‐specific antigen with clinicopathological features of screening‐detected cancer were also investigated. Results A total of 1405 men (13.2%) showed serum prostate‐specific antigen above 2.0 ng/mL and 68 (0.6%) were diagnosed with prostate cancer during the observation period. Cumulative probabilities of increased prostate‐specific antigen above 2.0 ng/mL over 10 years were 7.7%, 18.3%, 57.3%, and 88.7% in men with baseline prostate‐specific antigen levels of 0.0–0.5, 0.6–1.0, 1.1–1.5, and 1.6–2.0 ng/mL, respectively. The cumulative probabilities of developing prostate cancer at 4 years in men with baseline prostate‐specific antigen of 0.0–1.0 and 1.1–2.0 ng/mL were 0.05% and 1.10%, respectively. Patients with unfavorable clinicopathological features were diagnosed at 3 years, and at 1 year after the initial screening visit in men with baseline prostate‐specific antigen levels of 0.0–1.0 and 1.1–2.0 ng/mL, respectively. Conclusions The cumulative probabilities of increased prostate‐specific antigen and developing prostate cancer significantly increase with higher baseline prostate‐specific antigen ranges. Our database could contribute to the establishment of a natural history‐adjusted screening system in the future.