The role of radiotherapy in node-positive prostate cancer.

ABSTRACT

Node-positive prostate cancer represents 12% of newly diagnosed prostate cancer cases in the United States; with decreasing use of screening, this proportion is likely to increase. However, very few clinical trials have specifically compared treatment options for this group of patients. Radiotherapy has a potential role as both definitive therapy and adjuvant therapy for node-positive prostate cancer. In regard to definitive treatment, retrospective studies comparing androgen deprivation therapy (ADT) alone vs ADT plus radiotherapy consistently demonstrated better survival associated with radiotherapy. In addition, two secondary analyses of clinical trial data compared radiotherapy alone vs radiotherapy plus ADT in this setting, and showed combination treatment achieved better survival. In terms of adjuvant treatment after prostatectomy in the setting of pathologic node-positive disease, the Eastern Cooperative Oncology Group (ECOG) 3886 trial established ADT as a standard of care. Institutional retrospective studies showed that ADT plus radiotherapy was associated with improved overall survival compared with ADT alone, but an analysis of the population-based Surveillance, Epidemiology and End Results-Medicare linked data did not show a benefit from radiotherapy. Because current management is informed by mostly retrospective studies, clinical trials are needed to more definitively guide treatment decisions for patients with node-positive disease. Off trial, radiotherapy with ADT should be offered to patients with this very aggressive form of prostate cancer.