Evidence Lacking to Compare Prostate Cancer Treatments
Paucity of clinically important information seen as barrier to well-informed decision-making
WEDNESDAY, Feb. 6 (HealthDay News) -- In men who are diagnosed with localized prostate cancer, there isn't enough evidence to establish the relative benefits and harms of any available treatment option, including watchful waiting, prostatectomy, radiotherapy and androgen deprivation, according to a systematic review published online Feb. 5 in advance of publication in the Annals of Internal Medicine.
Timothy J. Wilt, M.D., of the University of Minnesota School of Medicine in Minneapolis, and colleagues reviewed 18 randomized controlled trials and 473 observational studies.
The investigators found that most studies assessed within-treatment rather than between-treatment category differences and were not sufficiently powered to assess overall or disease-specific survival or metastatic spread. They also found that only three randomized controlled trials compared surgery with watchful waiting or radiation therapy, and that these studies were either old or were conducted before the introduction of prostate-specific antigen (PSA) testing. No randomized controlled trials have evaluated primary androgen deprivation, cryotherapy, brachytherapy, intensity-modulated radiation therapy and proton-beam radiation therapy, the researchers report.
"Little high-quality evidence is available to guide patients and their families and health care providers on the comparative effectiveness and harms of treatments for clinically localized prostate cancer, especially in men with PSA-detected disease," the authors write. "Because the quality of evidence on treatment effectiveness, necessity and harm was limited, we could not accurately assess many clinically important outcomes. All treatments cause adverse events (primarily urinary, bowel and sexual) that occur soon after therapy, although the frequency, duration and severity vary among treatments."