Prostate cancer multifocality: impact on cancer biology and treatment recommendations

Subtotal ablative therapies may be a compromise between radical therapy and active surveillance, but oncologic efficacy and quantification of the side effects need to be evaluated in clinical trials. Depending on the eligibility criteria and ablative templates performed, trials of subtotal therapy have the opportunity to provide the scientific community with probative data regarding the biologic and clinical significance of index lesions and further support the hypothesis that multifocality of disease is rarely clinically relevant. This article will review the contemporary pathologic data assessing the intraprostatic heterogeneity of clinically localized prostate cancer and discuss the implications of multifocal disease on clinical trials involving subtotal ablative therapies. We will also discuss limitations in the current definitions of clinical significance as well as the limitations of our current staging techniques.