Active surveillance for prostate cancer: progress and promise.

Widespread prostate-specific antigen (PSA) -based screening and aggressive treatment of prostate cancer have reduced mortality rates substantially, but both remain controversial in large part because of high rates of overdiagnosis and overtreatment of otherwise indolent tumors. Active surveillance--or close monitoring of PSA levels combined with periodic imaging and repeat biopsies--is gaining acceptance as an alternative initial management strategy for men with low-risk prostate cancer. In reported series, rates of progression to active treatment with intermediate-term follow-up have ranged from 14% to 41%, and likelihood of subsequent cure with surgery or radiation does not seem to be compromised by an initial trial of surveillance. Two related challenges to broader acceptance of surveillance are better characterization at time of diagnosis of the risk of progression (including likelihood that given tumor may have been undersampled by diagnostic biopsy) and validation of optimal end points once surveillance begins. Both are subjects of intense ongoing investigation, with emerging biomarkers and novel imaging tests expected to facilitate decision making substantially. Recent reports have suggested active surveillance can be a cost-effective approach and preserve quality of life, but these questions must be assessed more definitively in prospective cohorts. Ultimately, by minimizing the harms of overtreating low-risk prostate cancer, active surveillance may help settle the controversy surrounding prostate cancer screening and management.