A study examined functional outcomes over five years correlated with five different treatments for localized prostate cancer.
It is critical for patients to understand possible adverse effects associated with contemporary cancer treatments, according to the researchers, because this will help them make informed treatment decisions.
To that end, the study authors performed a prospective, population-based cohort study on patients with favorable-risk (clinical stage cT1 to cT2bN0M0, prostate-specific antigen [PSA] ≤20 ng/mL, and Grade Group 1-2) prostate cancer (n = 1,386) and unfavorable-risk (clinical stage cT2cN0M0, PSA of 20-50 ng/mL, or Grade Group 3-5) prostate cancer (n = 619) who were diagnosed between 2011 and 2012. Patients were recruited from five Surveillance, Epidemiology and End Results Program sites and a U.S. prostate cancer registry. The following treatments were evaluated in favorable-risk disease patients: active surveillance (n = 363), nerve-sparing prostatectomy (n = 675), external beam radiation therapy (EBRT; n = 261), and low-dose-rate brachytherapy (n = 87). Men with unfavorable-risk disease received either prostatectomy (n = 402) or EBRT with androgen deprivation therapy (n = 217). The primary outcome was patient-reported function five years after treatment, measured using the 26-item Expanded Prostate Index Composite. The researchers employed adjusted regression models for baseline function and patient and tumor characteristics. The following minimum clinically important differences were established: sexual function, 10 to 12; urinary incontinence, 6 to 9; urinary irritative symptoms, 5 to 7; and bowel and hormonal function, 4 to 6.
Prostate Cancer Outcomes Differ by Risk
Final analysis included completed data from 2,005 patients (median [interquartile range] age, 64 [59-70] years; 1,993 [77%] were non-Hispanic white). Nerve-sparing prostatectomy, compared to active surveillance, resulted in poorer five-year urinary incontinence (adjusted mean difference, –10.9; 95% confidence interval [CI], –14.2 to –7.9) and three-year sexual function (adjusted mean difference, –15.2; 95% CI, –18.8 to –11.5). Low-dose-rate brachytherapy, compared to active surveillance, was predictive of worse one-year urinary irritative (adjusted mean difference, –7.0; 95% CI, –10.1 to –3.9), sexual (adjusted mean difference, –10.1; 95% CI, –14.6 to –5.7), and bowel (adjusted mean difference, –5.0; 95% CI, –7.6 to –2.4) function. EBRT in favorable-disease men did not largely differ from active surveillance at any point in the study in terms of urinary, sexual, and bowel function changes.
In the unfavorable-risk disease group, EBRT with ADT, compared to prostatectomy, resulted in worse six-month hormonal function (adjusted mean difference, –5.3; 95% CI, –8.2 to –2.4) and one-year bowel function (adjusted mean difference, –4.1; 95% CI, –6.3 to –1.9), but better five-year sexual function (adjusted mean difference, 12.5; 95% CI, 6.2–18.7) and incontinence at every time point over the five-year study period (adjusted mean difference, 23.2; 95% CI, 17.7–28.7).
The study results were published in JAMA.
The researchers summarized, “In this cohort of men with localized prostate cancer, most functional differences associated with contemporary management options attenuated by 5 years. However, men undergoing prostatectomy reported clinically meaningful worse incontinence through 5 years compared with all other options, and men undergoing prostatectomy for unfavorable-risk disease reported worse sexual function at 5 years compared with men who underwent EBRT with ADT.”