No increased prostate cancer incidence after negative transrectal ultrasound guided multiple biopsies in men with increased prostate specific antigen and/or abnormal digital rectal examination

Abstract

Purpose: We investigated the incidence of prostate cancer after negative transrectal ultrasound (TRUS) guided multiple biopsies. Our secondary aim was to calculate the sensitivity of the extended protocol used.

Materials and methods: A cohort of 547 men with elevated prostate specific antigen and/or abnormal digital rectal examination but with results negative for prostate cancer on a mean of 9 TRUS guided biopsies was followed through record linkage to the national cancer Registry. The observed number of prostate cancers was compared with the expected number during the same calendar period in an age matched male population to determine the standardized incidence ratio. The sensitivity of TRUS with multiple biopsies after 5 years of followup was calculated. Relative survival was estimated if there was an excess death rate due to undiagnosed prostate cancer.

Results: We found 11 men diagnosed with prostate cancer. The expected number in the age standardized male population was 15, resulting in a standardized incidence ratio of 0.8 (95% CI 0.4 to 1.2). Five-year sensitivity of the extended protocol of TRUS guided biopsies was 95.2% (95% CI 93.5 to 96.4) and relative survival was more than 100%, indicating a selection of men deemed candidates for curative treatment.

Conclusions: Men with clinical suspicion of prostate cancer who are examined by an extended protocol of TRUS guided biopsies negative for cancer do not have an increased incidence of prostate cancer within 6 years compared with an age matched male population. Five-year sensitivity of this protocol was high.