Five-year outcomes after prostatectomy or radiotherapy for prostate cancer: The prostate cancer outcomes study

Background: Men treated for clinically localized prostate cancer with either radical prostatectomy or external beam radiotherapy usually survive many years with the side effects of these treatments. We present treatment-specific quality-of-life outcomes for prostate cancer patients 5 years after initial diagnosis. Methods: The cohort consisted of men aged 55-74 years who were newly diagnosed with clinically localized prostate cancer in 1994-1995 and were treated with radical prostatectomy (n = 901) or external beam radiotherapy (n = 286). We used clinical and quality-of-life data previously collected at the time of diagnosis (i.e., baseline) and at the 2-year follow-up and data newly collected at 5 years after diagnosis to compare urinary, bowel, and sexual function and to examine temporal changes in those functions. Odds ratios (ORs) and adjusted percentages were calculated by logistic regression. All statistical tests were two-sided. Results: At 5 years after diagnosis, overall sexual function declined in both groups to approximately the same level. However, at 5 years after diagnosis, erectile dysfunction was more prevalent in the radical prostatectomy group than in the external beam radiotherapy group (79.3% versus 63.5%; OR = 2.5, 95% confidence interval [CI] = 1.6 to 3.8). Approximately 14%-16% of radical prostatectomy and 4% of external beam radiotherapy patients were incontinent at 5 years (OR = 4.4, 95% CI = 2.2 to 8.6). Bowel urgency and painful hemorrhoids were more common in the external beam radiotherapy group than in the radical prostatectomy group. All of these differences remained statistically significant after adjustment for confounders and for differences between treatment groups in some baseline characteristics. Conclusions: At 5 years after diagnosis, men treated with radical prostatectomy for localized prostate cancer continue to experience worse urinary incontinence than men treated with external beam radiotherapy. However, the two treatment groups were more similar to each other with respect to overall sexual function, mostly because of a continuing decline in erectile function among the external beam radiotherapy patients between years 2 and 5.