Abstract: PD03-04
Sources of Funding: None

Introduction

Transrectal ultrasound-guided prostate biopsies (TRUS-Bx) have a high false-negative rate, and thus men with a negative TRUS-Bx frequently undergo repeat biopsies leading to subsequent diagnoses of prostate cancer (PCa). Long-term outcome data on such patients is lacking, as previous studies have only reported the short-term rates of PCa diagnosis in small cohorts of men with a negative TRUS-Bx. Our objective was to determine both the long-term rates of PCa diagnosis and all-cause mortality in a large, population-based cohort of men with a single negative TRUS-Bx.

Methods

This was a retrospective, population-based study of 124,067 men who had an initially negative TRUS-Bx in Ontario, Canada between April 1994 and March 2015. All included men were older than 40 years and had no prior history of PCa. Using data from the Ontario Health Insurance Plan, Ontario Cancer Care Registry, and Registered Persons Database, housed at the Institute of Clinical and Evaluative Sciences, we were able to determine the 5, 10, 15, and 20 year rates of PCa diagnosis and all-cause mortality in such men.

Results

Mean age at date of first negative TRUS-Bx was 63.55 years (SD=8.75). Total follow-up time was 974986.07 person-years, with mean follow-up per patient at 7.86 years (SD=5.37). The total number of subsequent PCa diagnoses was 21,869, accounting for an incidence rate of 22.25 per 1000 person-years. The 5, 10, 15, and 20-year rates of PCa diagnosis were 0.130, 0.187, 0.220, and 0.239, respectively. The total number of deaths in our cohort was 21,375, accounting for a death incidence rate of 21.92 per 1000 person-years. The 5, 10, 15, and 20-year all-cause mortality rates were 0.068, 0.155, 0.260, and 0.380, respectively.

Conclusions

Based upon these long-term population-based data, a significant proportion of men with an initially negative TRUS-Bx subsequently receive a diagnosis of PCa, with risk of diagnosis continuously rising. These data suggest that long term follow up of at risk men is warranted.

Funding

None