Prostate specific-antigen distribution in asymptomatic Canadian men with no clinical evidence of prostate cancer

Abstract

Objective: To examine prostate specific-antigen (PSA) levels and percentage free/total PSA (f/tPSA) distributions as well as digital rectal examination (DRE) profiles in asymptomatic Canadian men with no established prostate cancer diagnosis, as recent data indicate that a man's risk of developing prostate cancer is higher if his baseline PSA level is above the median for his age group.

Subjects and methods: We used data obtained during an early prostate cancer-detection event. An invitation to an onsite DRE, PSA level and f/tPSA assessment was accepted by 313 men. Serum PSA level and f/tPSA were measured before the DRE. A suspicious DRE and/or PSA level of > or = 2.5 ng/mL or f/tPSA of < or = 15% represented indications for a systematic 12-core ultrasonography-guided prostate biopsy.

Results: Of all the 313 men, most (235, 75%) had PSA levels of 0.01-1.53 ng/mL and an f/tPSA of >15% (285, 91.1%). The median (range) PSA level was 0.8 (0-34.2) ng/mL and f/tPSA was 27.4 (6.7-100)%. Age-specific median PSA levels and f/tPSA were, respectively, 0.7, 0.9, 1.0, 1.5 ng/mL and 31%, 27%, 26%, 25% for men aged 40-49, 50-59, 60-69 and 70-79 years. A suspicious DRE was recorded in 55 (17.6%) men, with eight (8.8%), 26 (20.0%), 14 (20.6%), and seven (28.9%) having suspicious DRE findings according to above age categories. Overall, seven (2.2%) prostate cancers were detected.

Conclusion: The median age-specific baseline PSA levels and f/tPSA represent valuable indicators of prostate cancer risk. The population-specific baseline median PSA level should not be >1.0 ng/mL and the baseline f/tPSA should be >30%. Men with values outside of these ranges should be considered at greater risk of prostate cancer.