Prostate cancer overdiagnosis and overtreatment

Abstract

To summarize the evidence, now extensive, that efforts to reduce prostate cancer mortality by screening and early detection result in overdiagnosis of disease that is clinically insignificant, and would never have been diagnosed in the patient's lifetime in the absence of screening. Overdiagnosis may result in overtreatment, which in the case of prostate cancer often carries significant, long-term quality-of-life effects. The review also addresses the solutions to the problem of overdiagnosis and overtreatment, and summarizes the outcomes of these approaches. Screening for prostate cancer has been demonstrated to reduce mortality, although with a high number needed to treat. One approach to this problem is to offer patients with favorable risk disease an initial conservative approach, with close monitoring and treatment for those patients who are reclassified as higher risk over time. Much preclinical data indicates that Gleason 6 prostate cancer does not carry the hallmarks of malignancy. However, a number of recent studies have demonstrated that in patients diagnosed with favorable risk prostate cancer (Gleason 6 or less, prostate-specific antigen <10), about 30% will harbor higher grade cancer and benefit from treatment. These patients are identifiable by a combination of repeat biopsy, serial prostate-specific antigen, and in borderline cases, multiparametric MRI. Active surveillance is a powerful solution to the problem of overdiagnosis and overtreatment associated with screening for prostate cancer. For the 40-50% of patients with favorable risk prostate cancer, it offers the benefit of personalized medicine, avoiding treatment and related quality-of-life effects altogether in the majority, and providing definitive management for the minority who are reclassified with higher risk disease over time.