Goserelin alone improved survival, decreased recurrence in premenopausal women with early breast cancer

Goserelin reduced the long-term risk for disease recurrence and mortality in premenopausal women with early breast cancer who were not receiving tamoxifen, according to data from an analysis of the Zoladex in Premenopausal Patients trial.

The analysis included a long-term follow-up of 2,706 women from the trial. Patients were randomly assigned to one of four treatment arms: goserelin (Zoladex, AstraZeneca; 3.6-mg injection every four weeks), tamoxifen (20 mg or 40 mg daily), both treatments or neither for two years after primary therapy. The researchers examined the efficacy of goserelin, with or without tamoxifen, on event-free survival, OS, risk for recurrence of breast cancer and risk for mortality.

Fifteen years after treatment initiation, 13.9 fewer events per 100 women occurred among patients who were assigned to goserelin alone compared with those assigned to neither drug. Among patients assigned to both drugs, adding goserelin to tamoxifen resulted in 2.8 fewer events per 100 patients but did not reach statistical significance.

Breast cancer mortality was lower by 8.5 per 100 women among those assigned to goserelin alone compared with those assigned to neither drug. Among patients assigned to both goserelin and tamoxifen, adding goserelin resulted in 2.6 fewer deaths per 100 women, but the reduction did not reach statistical significance.

Based on their findings, the researchers concluded, “It may be that women who are unlikely to complete five years of tamoxifen tablets may prefer two years of goserelin injections. It may also be reasonable to recommend both therapies to minimize the reduction in bone mineral density associated with endocrine treatment.”

Hacksaw A. J Natl Cancer Inst. 2009;101:341-349.