Overdiagnosis and overtreatment of prostate cancer.
Prostate cancer is a ubiquitous disease, affecting as many as two-thirds of men in their 60s. Through widespread prostate-specific antigen (PSA) testing, increasing rates of prostate biopsy, and increased sampling of the prostate, a larger fraction of low-grade, low-volume tumors have been detected, consistent with tumors often found at autopsy. These tumors have historically been treated in a manner similar to that used for higher-grade tumors but, more recently, it has become evident that with a plan of active surveillance that reserves treatment for only those patients whose tumors show evidence of progression, very high disease-specific survival can be achieved. Unfortunately, the frequency of recommendation of an active surveillance strategy in the United States is low. An alternative strategy to improve prostate cancer detection is through selected biopsy of those men who are at greater risk of harboring high-grade, potentially lethal cancer. This strategy is currently possible through the use of risk assessment tools such as the Prostate Cancer Prevention Trial Risk Calculator (www.prostate.cancer.risk.calculator.com) as well as others. These tools can predict with considerable accuracy a man's risk of low-grade and high-grade cancer, allowing informed decision making for the patient with a goal of detection of high-risk disease. Ultimately, other biomarkers including PCA3, TMPRSS2:ERG, and [-2]proPSA will likely aid in discriminating these two types of cancer before biopsy.
From the Cancer Therapy and Research Center, University of Texas Health Science Center at San Antonio, San Antonio, TX.
Ian M
IM
Thompson