PSA Doubling Time as a Predictive Factor on Repeat Biopsy for Detection of Prostate Cancer

imbo M, Tomioka S, Sasaki M, Shima T, Suzuki N, Murakami S, Nakatsu H, Shimazaki J.
1Department of Urology, Asahi General Hospital, Asahi.

OBJECTIVE: Detection of prostate cancer needs a biopsy of the prostate. Suspecting cancer from an increase in Prostate Specific Antigen (PSA) has a high negative rate at an initial prostate biopsy. Cases with negative initial biopsy may be the candidates of subsequent biopsy. For lowering unnecessary repeat biopsy, the use of predictive factors before a repeat biopsy is applied for indication.

METHODS: Seventy-seven cases with negative initial prostate biopsy received a repeat biopsy and factors for the detection of cancer were examined.

RESULTS: Prostate Specific Antigen doubling time distinguished a part of cancer cases. Its sensitivity of 30, 50 and 70 months was 36.6%, 30.4% and 10%, respectively. Cancer case did not show PSA doubling time of >100 months in general. Values of PSA transition zone density, %Free/total PSA and PSA velocity were similar between cancer and no cancer cases.

CONCLUSIONS: Prostate Specific Antigen doubling time was one of the predictive factors for the detection of prostate cancer and was valuable for avoiding unnecessary repeat biopsy in some cases.