Patients with early-stage prostate cancer treated with external beam radiation have shorter survival than men treated with brachytherapy or radical prostatectomy, according to a presentation at the American Society of Clinical Oncology’s Prostate Cancer Symposium.

The analysis from the Cleveland Clinic was the first to assess the effect of the three treatment strategies on overall survival.

“These findings indicate that the three major forms of treatment for early-stage prostate cancer are not necessarily equivalent in terms of overall survival,” said Jay Ciezki, MD, Staff Physician in the Cleveland Clinic’s Department of Radiation Oncology and the study’s lead author. “Moreover, these findings persisted after controlling for potential confounding factors, such as age, other illnesses, and smoking history.”

The researchers analyzed five-year overall survival among 2,285 US men with low- or intermediate-risk prostate cancer: 662 men treated with brachytherapy, 570 men treated with external beam radiation therapy, and 1,053 men treated with radical prostatectomy. All patients were treated at the Cleveland Clinic between 1996 and 2003.

The researchers controlled for factors such as Charlson score (a validated measure of a patient’s general health, including comorbid conditions), age, smoking status, cardiovascular risk factors such as elevated cholesterol, and alcohol use, among others.

After five years (median follow-up was 59 months), 93.8 percent of men who received external beam radiation therapy were alive compared with 95.7 percent of men who received brachytherapy and 97.7 percent of men who had surgery.

After controlling for confounding factors, brachytherapy and surgery were found to be equally effective, while external beam radiotherapy remained less effective. Smoking, increasing Charlson score, and age were independently associated with reduced overall survival.