Correlation of initial PSA level and biopsy features with PSA-doubling time in early stage prostate cancers in Japanese men

Objective: To distinguish good candidates for watchful waiting from those who need immediate treatment in localized prostate cancer. Methods: Prostate specific antigen (PSA)-doubling time (DT) was calculated by a log-linear regression model for 78 patients with clinically localized prostate cancer (T1c: 47, T2a: 6, T2b: 21, and T3: 4) under surveillance. Median observation period was 37.5 months. The first 1-year PSA-DT was compared with the overall PSA-DT in 41 patients who had been under surveillance for more than 3 years. Results: There was significant difference in the PSA-DT distribution between a pooled group of T1c and T2a and a group of T2b and T3 patients (median 58.8 versus 33.3 months, P = 0.0052). A combination of three parameters consisting of initial PSA level less than 10 ng/ml, WHO grade 1, one or two positive core per six to eight systematic biopsy cores with 50% or less cancer involvement significantly correlated with PSA-DT distribution in the T1c plus T2a group (P = 0.0034). The first year assessment of PSA-DT was identical to the overall assessment in 48.8%, 2 years or more in 36.6%, while it was 2 years or less (possibly over-estimated) in 14.6%. Conclusion: PSA-DT can be predictable to some extent with the initial PSA level and biopsy features in early stage prostate cancers. Prospective study is needed to clarify whether temporary observation together with PSA-DT estimation is a safe strategy and is complementary to clinico-pathological parameters at diagnosis.