Side effects of modern PCa treatments compared

Boston—Despite technological advances in treatment for localized prostate cancer, men continue to experience clinically meaningful side effects that affect quality of life, according to an examination of data from a prospective population-based cohort study.

Baseline function and treatment are the strongest predictors of functional outcomes. As a result, disease management should be individualized using disease risk, baseline function, and patient preference in selection of treatment, said Daniel Barocas, MD, MPH, at the AUA annual meeting in Boston.

“The bottom line of this study is that treatments have side effects; we knew this to begin with and it’s not much different for the newer treatments than for older treatments, and that means that we should consider active surveillance [AS] when it’s appropriate,” said Dr. Barocas, associate professor of surgery, Vanderbilt University, Nashville, TN, working with David F. Penson, MD, MPH, patient research partner Ralph Conwill, and colleagues.

Few high-quality studies have evaluated the impact of contemporary treatments such as robotic radical prostatectomy, external beam radiation therapy (EBRT), and active surveillance (AS). Therefore, Dr. Barocas and colleagues sought to compare functional outcomes and adverse effects associated with radical prostatectomy (either open or robotic), EBRT, and AS in a contemporary population-based cohort of prostate cancer survivors using the Comparative Effectiveness Analysis of Surgery and Radiation (CEASAR), which is a prospective, population-based cohort study of men diagnosed with localized prostate cancer in 2011-2012.

Patients in CEASAR were accrued at the time of diagnosis through the five Surveillance, Epidemiology, and End Results registry sites and from the Cancer of the Prostate Strategic Urologic Research Endeavor. Patients were administered the Expanded Prostate Index Composite questionnaire at baseline, 6 months, 12 months, and 3 years. The questionnaire contained 26 items related to disease-specific quality of life, and each domain was scored from 0 to 100, with higher scores indicating better function.

Inclusion criteria were age 80 years and younger, newly diagnosed cT1 or cT2 prostate cancer, enrollment within 6 months of diagnosis, and a PSA level <50.0 ng/dL. Some 3,269 men met these inclusion criteria, 2,750 of whom were managed with either RP, EBRT, or AS. Two hundred more men were excluded because they did not complete a follow-up survey, leaving 2,550 men in the analytic cohort: 1,523 who were managed with RP, 598 with EBRT, and 429 with AS.

Men who had EBRT were slightly older than those who had RP (68.1 vs. 61.5 years). More high-risk men were treated with EBRT (25%) than with RP (17%) or AS (4%). Forty-five percent who underwent EBRT had hormone therapy in the first year compared with 5% and 1% of the RP and AS groups, respectively.

UI most problematic with RP

Men undergoing RP had a significant decline in score on the urinary incontinence domain at 3 years compared with the AS group (–13.4 points; p<.001) and the EBRT group (–18 points; p<.001). Differences of at least six points were considered clinically important. On multivariable analysis, RP and baseline function were the dominant predictors of functional outcome. About 14% of men who underwent RP reported urinary incontinence as at least a moderate problem compared with 5% of men who chose EBRT and 6% who chose AS(p<.001).

Urinary irritative symptoms improved with RP compared with AS. On multivariable analysis controlling for baseline function, RP had a larger negative impact than EBRT on sexual function domain scores (–17.1 points; p<.001).

“Baseline score also has a big impact on your post-treatment function,” said Dr. Barocas. The difference between RP and EBRT was only significant among men with baseline function scores in the highest quartile. About 40% of men had erections insufficient for intercourse before treatment, he noted.

“The bottom line is that sexual function outcomes are not clinically relevant for all men,” he said.

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Bowel function scores decreased by a clinically significant amount (≥5 points) among men who chose EBRT versus AS, “but that difference is significant only up to about 1 year,” he said. “The same is true for the hormone therapy [domain] score.”

General quality of life was the same across treatments, as was disease-specific survival. Overall survival was higher for RP (99%) compared with EBRT (96%) and AS (97%), but this difference was significant only on unadjusted analysis (p<.001).

“There weren’t enough deaths to do a multivariable analysis, and the difference in survival is undoubtedly attributable to differences between groups in baseline characteristics,” Dr. Barocas said.

“Disease management should be individualized,” he concluded. “We hope that our information provides a basis for shared decision-making.”