Prostate cancer studies need to be stronger to help physicians make strong decisions

Physicians who treat men with prostate cancer encounter difficult choices, often because data from properly conducted studies are lacking.

In the first study, the European Organization for Research and Treatment of Cancer (EORTC) provided long-term data (9.1-year median follow-up) on the use of radiation therapy (RT) plus androgen deprivation therapy (ADT) in locally advanced disease following radical prostatectomy (RP) (see page 1). Patients in this large, prospective, randomized trial received either combined RT/ADT or RT alone for 3 years. Survival rates signifi cantly favored the combination approach.

The data are important in confirming the EORTC's earlier 5-year data on long-term RT/ADT, but also raise a few questions: First, how would patient outcomes differ if one group was randomized to ADT alone versus combined ADT/RT in the second group, begging the question whether ADT alone is the active therapy? Second, is it possible that 1 or 2 years of ADT following RT is sufficient to gain the same outcome? (The superiority of 3 years of ADT versus 6 months of after RT had been shown previously.) Third, does ADT for 3 years raise the risk of metabolic syndrome?

This study brings up an important question, but the data are not strong enough to answer it. The number of patients is small (219), and the 4-year follow-up is too short to accurately gauge recurrence. Because patient data were retrospectively drawn from multiple institutions, the authors essentially examined a composite of patients with multiple factors that could cause local or distant recurrence.

It would be valuable to know-through a randomized, prospective study-that early RT could prevent PSA rise and which patients would most benefit from it. Such data are not available from this or any other study.

As a group, medical, surgical, and radiation oncologists who treat prostate cancer are deficient in carrying out the difficult but necessary studies to help patients with their treatment decisions. Good attempts have been made, but the effort needs to be increased considerably.

Dr. Williams, a Urology Times editorial consultant, is professor and chair, department of urology, University of Iowa, Iowa City.