Suppression of the male hormone androgen in locally advanced prostate cancer appears to be more successful when treatment is prolonged, according to Canadian and US researchers.

In a March 23rd online paper issued by the Journal of Clinical Oncology, Dr. Luis Souhami of Montreal General Hospital and colleagues report on an analysis of data for 189 patients who had taken part in a trial of therapy for locally advanced prostate cancer.

All received radiotherapy followed by goserelin given indefinitely or until disease progression. Surviving patients were followed for an average of 9.6 years and received adjuvant hormone therapy for an average of 2.2 years.

After adjustment for factors including age and the cancers degree of aggression, stratification by hormone therapy duration showed that therapy for more than 5 years was significantly associated with better overall survival and disease-free survival than was shorter duration therapy.

For example, the 5-year overall survival in this group was 100 percent, compared to 71.9 percent in those who received hormone therapy for a year or less. The corresponding survival rate in patients who had received between 1 and 5 years of therapy was 66.7 percent.

However, Dr. Souhami told Reuters Health, “Although our analysis gives strong support to the hypothesis that long-term hormonal therapy leads to better outcome than the standard two- to three-year regimen, it is clear that a well-designed randomized trial is needed to definitively answer this question.”

SOURCE: Journal of Clinical Oncology, March 23, 2009.