In NEJM this week, researchers in the US and Canada present results from a study of radiotherapy and short-term androgen deprivation for the treatment of localized prostate cancer. From 1994 through 2001, the team randomly assigned 1,979 prostate cancer patients to receive radiotherapy alone or with four months of total androgen suppression, and followed the patients for a median of 9.1 years. The researchers found that the 10-year rate of overall survival was 62 percent among patients receiving radiotherapy plus short-term androgen deprivation, compared with a 57 percent survival rate in the radiotherapy group. The addition of androgen deprivation was also associated with a decrease in the 10-year disease-specific mortality from 8 percent to 4 percent, the authors write. Biochemical failure, distant metastases, and the rate of positive findings on repeat prostate biopsies were also "significantly improved" with the addition of androgen deprivation to radiotherapy, the team adds.
In an NEJM editorial this week, the Dana-Farber Cancer Institute's Anthony D'Amico says that while the results of the recent study indicate that some men may benefit from a combination of radiotherapy and hormonal treatment for prostate cancer, men with low-risk disease appear not to benefit. Other studies have also shown that hormonal therapy isn't indicated in men with low-risk disease, particularly because of the increased risk for diabetes, heart attack, stroke, and sudden death that can come along with such treatments, D'Amico says. However, he adds, it is worth determining whether there is a benefit of combination therapy for men with low-risk disease and an adverse factor and whose prostate biopsies may have missed a higher grade of disease. "In conclusion, among men with localized prostate cancer undergoing conventional-dose radiation therapy, hormonal therapy is not indicated for low-risk disease, whereas six months of hormonal therapy appears necessary to prolong survival among patients with high-risk disease," D'Amico says. "Whether four or six months of hormonal therapy for intermediate-risk disease is best requires further study."