Wallis CJD, Zhao Z, Huang LC, et al. - This study of localized prostate cancer cases revealed that treatment-related regret was experienced by more than 1 in 10 patients. Rates of regret seem to vary between treatment approaches in a fashion that is mediated by functional results and patient expectations.

• This is a prospective, population-based cohort of 2,072 patients with prostate cancer.

• At 5 years, treatment-related regret was experienced by 183 (16%) of those undergoing surgery, 76 (11%) receiving radiotherapy, and 20 (7%) of those undergoing active surveillance.

• Relative to active surveillance, a significantly greater probability of expressing regret was observed in patients who underwent surgery (adjusted odds ratio [aOR], 2.40), whereas patients who had radiotherapy were not associated with an elevated likelihood of experiencing regret (aOR, 1.53); posttreatment functional outcomes were related to mediations in this finding.

• Sexual dysfunction was significantly related to regret (aOR for change in sexual function from baseline, 0.65 [95% CI, 0.52-0.81]).

• Subjective patient-perceived treatment efficacy (aOR, 5.40) as well as adverse effects (aOR, 5.83), vs patient expectations prior to treatment, were related to treatment-related regret.

• Other patient features, such as participatory decision-making tool scores (aOR, 0.80), social support (aOR, 0.78), and age (aOR, 0.78), were significantly linked with regret.