The excess burden of side-effects from treatment in men allocated to screening for prostate cancer. The Göteborg randomised population-based prostate cancer screening trial

Background: The number of men needed to treat to prevent one death is rather high in prostate cancer screening. How this affects the burden of treatment-related side-effects is unclear. The aim of this study was to evaluate the treatment related morbidity following radical prostatectomy in men participating in the Göteborg randomised population-based prostate cancer screening trial.

Methods: In 1995, 20,000 men aged 50-64 years were randomly allocated (1:1) to biennial PSA-screening or to a control group not invited. A subset of prostate cancer patients undergoing radical prostatectomy between 2001 and 2008 responded to questionnaires preoperatively and at 18 months postoperatively. The primary endpoint was patient-reported frequencies of erectile dysfunction as measured by the validated International Index of Erectile Function-5 questionnaire and urinary incontinence as assessed by use of pads. Analyses were made according to intention to screen.

Findings: After 14 years of follow-up, a total of 1849 men were detected with prostate cancer (1138 screened versus 711 controls, excluding 7 cancers detected at autopsy in the control group). Overall, 1047 received treatment with curative intent and radical prostatectomy was performed in 829 cases (79.2%). In this study, 294 of these men participated (205 screened and 89 controls). Of preoperatively potent men 79.1% (91/115) in the screening-group and 90.7% (49/54) in the control-group became impotent or sexually inactive 18 months postoperatively, whereas 14.3% (29/203) of screened men and 20.5% (18/88) of controls were considered postoperatively incontinent (regular use of pads). Extrapolated data yields that 120/10,000 more men become impotent and 25/10,000 more men will have the need of pads among men invited to regular PSA screening. The 'cost' per life saved at the same follow-up of screening is four men impotent and less than one man incontinent.

Interpretation: Despite the relatively high risk of erectile dysfunction and incontinence following radical prostatectomy for prostate cancer, the excess burden of permanent side-effects after population-based screening can be regarded as relatively low, when related to the number of men saved from prostate cancer death. These data can be useful when calculating the harms and benefits of screening. However, the outcome on a population-level may differ from the benefit for the individual.