Natural History of Untreated Localized Prostate Cancer: Rational for Active Surveillance

Abstract

The treatment of localized prostate cancer remains controversial, especially for tumors detected by prostate-specific antigen (PSA) testing. Although the lifetime risk of receiving a prostate cancer diagnosis is about 17%, the risk of dying from this disease remains around 3%. This suggests that many men are unlikely to benefit from treatments. When assessing the value of any intervention, men must first understand the threat posed by their disease and then determine how likely interventions will alter this outcome.

The most powerful predictor of the natural history of prostate cancer continues to be the Gleason score. Men with high-grade disease (Gleason 8–10) have a high probability of disease progression and often die from prostate cancer 5–10 years after diagnosis depending upon whether the disease is localized or metastatic at diagnosis. Men with screen-detected, high-grade, localized disease often have an additional 5 years before they succumb to their disease. Men with screen-detected, low-volume, low-grade prostate cancer have the best prognosis. In the absence of intervention, many are likely to survive at least 15–20 years without symptoms or evidence of disease progression. Prostate cancer mortality is less than 5%. These are the men who may want to consider active surveillance. Men diagnosed with screen-detected intermediate-grade disease (Gleason 7) are the most difficult to counsel. Clinical symptoms are unlikely to occur for at least 10 or possibly 15 years. As a consequence older men may wish to monitor their disease, while younger may wish to seek intervention.