What is 'insignificant' prostate carcinoma?

In the absence of clinical context, current definitions of insignificant prostate carcinoma are not useful in assessing the need for definitive treatment. Nonetheless, the findings of Bastian and colleagues, which are reported in the current issue of Cancer, strongly suggest that the Epstein criteria select for a subset of patients who may not require immediate therapy and who, at least initially, may be followed safely. The remaining challenge for the urologic community is to design clinical trials aimed at prospectively identifying individuals who require further intervention and determining when such intervention is necessary. Only after the completion of trials such as these can an accurate definition of 'insignificant' prostate carcinoma be put forth.