Prostate Biopsy - Cancer detection and risk of complications

Abstract

The overall aim of this thesis was to investigate if a sampling protocol with anterior biopsies of prostate increase cancer detection at first repeat biopsy, to evaluate if a clinical routine with urine culture prior to transrectal prostate biopsy influences risk for post-biopsy infection and to identify risk factors for infection after transrectal prostate biopsy. A prostate biopsy is a common invasive procedure in urology. Every prostate biopsy, no matter the route, carries a risk for complication and is an uncomfortable procedure for the patient. It is therefore important that every procedure has a high precision for detecting significant prostate cancer and is carried out with knowledge of how to minimize procedural morbidity. Paper I reports a randomised trial for sampling of the anterior prostate with end-fire technique at first repeat transrectal prostate biopsy to increase detection rate of prostate cancer. It included 344 men from 2010 to 2018 in Region Kronoberg. The sampling with anterior biopsies using end-fire technique did not significantly increase cancer detection at first repeat biopsy. In 2014, as part of an antimicrobial stewardship program, our region initiated a routine with a urine culture prior to prostate biopsy. Paper II reports a register-based evaluation of this clinical routine with a historical control group. We concluded that the routine with urine culture prior to prostate biopsy did not reduce the rate of post-biopsy infection. In Paper III, a regional register study was designed to identify risk factors for infection after transrectal prostate biopsy. Diabetes and a previous urinary tract infection were confirmed as risk factors, but also potentially new risk factors such as a previous treatment with non-UTI antibiotics and symptoms from lower urinary tract. Risk factors associated with infection in Paper III were then used in Paper IV. A nationwide register study to investigate the cumulative effect of risk factors for infection after transrectal prostate biopsy also including immunosuppressive treatment, systemic corticosteroids and treatment for overactive bladder as factors. The cumulative risk for infection after transrectal prostate biopsy increased from 4 % if none to 12 % if three risk factors were present.