For men with localised prostate cancer, surgery provides a survival benefit compared with watchful waiting. Treatments are associated with morbidity. Results for functional outcome and quality of life are rarely reported beyond 10 years and are lacking from randomised settings. We report results for quality of life for men in the Scandinavian Prostate Cancer Group Study Number 4 (SPCG-4) after a median follow-up of more than 12 years.

All living Swedish and Finnish men (400 of 695) randomly assigned to radical prostatectomy or watchful waiting in SPCG-4 from 1989 to 1999 were included in our analysis. An additional 281 men were included in a population-based control group matched for region and age. Physical symptoms, symptom-induced stress, and self-assessed quality of life were evaluated with a study-specific questionnaire. Longitudinal data were available for 166 Swedish men who had answered quality-of-life questionnaires at an earlier timepoint.

182 (88%) of 208 men in the radical prostatectomy group, 167 (87%) of 192 men in the watchful-waiting group, and 214 (76%) of 281 men in the population-based control group answered the questionnaire. Men in SPCG-4 had a median follow-up of 12·2 years (range 7–17) and a median age of 77·0 years (range 61–88). High self-assessed quality of life was reported by 62 (35%) of 179 men allocated radical prostatectomy, 55 (34%) of 160 men assigned to watchful waiting, and 93 (45%) of 208 men in the control group. Anxiety was higher in the SPCG-4 groups (77 [43%] of 178 and 69 [43%] of 161 men) than in the control group (68 [33%] of 208 men; relative risk 1·42, 95% CI 1·07–1·88). Prevalence of erectile dysfunction was 84% (146 of 173 men) in the radical prostatectomy group, 80% (122 of 153) in the watchful-waiting group, and 46% (95 of 208) in the control group and prevalence of urinary leakage was 41% (71 of 173), 11% (18 of 164), and 3% (six of 209), respectively. Distress caused by these symptoms was reported significantly more often by men allocated radical prostatectomy than by men assigned to watchful waiting. In a longitudinal analysis of men in SPCG-4 who provided information at two follow-up points 9 years apart, 38 (45%) of 85 men allocated radical prostatectomy and 48 (60%) of 80 men allocated watchful waiting reported an increase in number of physical symptoms; 50 (61%) of 82 and 47 (64%) of 74 men, respectively, reported a reduction in quality of life.

For men in SPCG-4, negative side-effects were common and added more stress than was reported in the control population. In the radical prostatectomy group, erectile dysfunction and urinary leakage were often consequences of surgery. In the watchful-waiting group, side-effects can be caused by tumour progression. The number and severity of side-effects changes over time at a higher rate than is caused by normal ageing and a loss of sexual ability is a persistent psychological problem for both interventions. An understanding of the patterns of side-effects and time dimension of their occurrence for each treatment is important for full patient information.

US National Institutes of Health; Swedish Cancer Society; Foundation in Memory of Johanna Hagstrand and Sigfrid Linnér.