Stats Don’t Lie: Avoiding Overtreatment of Prostate Cancer
Carter HB
BJU Int. 2011;108:1684-1695
Introduction
The most significant development in urology last year was the surprising recommendation from the US Preventive Services Task Force that routine prostate-specific antigen (PSA) testing in healthy men is not indicated for early detection of prostate cancer.[1] That draft recommendation has been soundly criticized in some circles and will probably be modified before it is finalized.
The rationale behind the recommendation, however, was the lack of randomized clinical trials showing that early detection leads to fewer cancer-specific deaths. Furthermore, early detection has led to overtreatment of patients with low-grade, low-risk cancer, in whom the side effects of prostate biopsy and subsequent treatment negatively outweigh the gain in cancer-specific survival, especially in elderly patients.
Evidence of this disconnect was seen in the National Cancer Institute’s Patterns of Care Study,[2] which found that 71% of men older than 75 years with favorable-risk disease received radiotherapy. Only 12% were managed with active surveillance.
Of course, the good news is that most patients identified through early screening have curable, localized disease, and the mortality rate from prostate cancer has decreased 30%-40% in the PSA era.[3]
Study Summary
In this excellent article, Carter provides current statistics on the treatment of patients with low-risk disease and discusses definitions of "low-risk" disease and current guidance for pursuing close observation rather than immediate intervention.
Can we define low-risk disease? Carter reviews 2 classification schemes from D’Amico and colleagues[4] and Epstein and colleagues[5] that have stood the test of time. However, there has been significant upgrading on surgical specimens, which has led to the recommendation for repeated biopsies in patients receiving close observation.
What do we know about patients with low-risk prostate cancer? Currently, patients with localized low-risk disease should be given the option of close observation. They should be informed that intervention with surgery or radiation reduces cancer-specific mortality by 50%, but that their cancer-specific mortality risk without treatment is less than 10%. These patients also need to be aware that the risk for cancer spread is low but does exist.
In the longest prospective study of 450 men followed with active surveillance for a median of 7 years, 10-year actuarial cancer-specific survival was 97% (and 17% of the patients were not low risk on entry).[6] Also, in a multi-institutional study, the 5-year probability of a patient remaining on active surveillance was 75%.[7]
In the future, identification of new molecular markers will give us a better definition of low-risk prostate cancer. At the present time, however, patients with low-risk disease should be informed about the pros and cons of close observation. Carter offers guidance for urologists in helping patients make an informed treatment choice.
