Prevalence of prostate cancer at different levels of serum prostate-specific antigen (PSA) and different free:total PSA ratios in a consecutive series of men referred for prostate biopsies

Abstract

Objective. In this retrospective study we report on the detection rate of prostate cancer (PCa) at different levels of prostate-specific antigen in serum (s-PSA) and at different PSA ratios (free:total PSA) during a 2-year period in patients without previously known PCa. Material and methods. During the years 2001 and 2002, 361 consecutive patients were examined with ultrasound-guided core needle biopsies at our department. The patients were biopsied due to an increased s-PSA level, a low PSA ratio or findings at digital rectal examination (DRE). Patients with previously known cancer (T1a/b or cancer already detected with fine-needle aspiration cytology) were excluded. We used the BioPince® biopsy needle, which has a stroke length of 32 mm. In 91% of the patients, eight biopsies were taken from the apex, mid-medial, mid-lateral and base positions bilaterally. Results. Of the 361 patients, 188 (52%) had PCa. Most cancers were T1c or T2 tumors (51% and 34%, respectively). Among patients with an s-PSA level of < 4 ng/ml, 8/35 (23%) had PCa. Five of 13 patients with a normal DRE (T1c) and an s-PSA level of < 4 ng/ml had PCa. In total, in the PSA ratio intervals 0.05–0.1 and 0.11–0.17, cancer was found in 71% and 51% of cases, respectively. In contrast, only 35% of patients had positive biopsies when the PSA ratio was normal (p<0.01). Conclusions. The overall cancer detection rate was high and a large proportion of patients with an s-PSA level of < 4 ng/ml had PCa. The risk of having PCa increased considerably with a low PSA ratio.

• Prostate cancer
• detection rate
• prostate-specific antigen level
• prostate-specific antigen ratio
• needle biopsies