Background

Ovarian failure is a common toxic effect of chemotherapy. Studies of the use of gonadotropin-releasing hormone (GnRH) agonists to protect ovarian function have shown mixed results and lack data on pregnancy outcomes.

Methods

We randomly assigned 257 premenopausal women with operable hormone-receptor-negative breast cancer to receive standard chemotherapy with the GnRH agonist goserelin (goserelin group) or standard chemotherapy without goserelin (chemotherapy-alone group). The primary study end point was the rate of ovarian failure at 2 years, with ovarian failure defined as the absence of menses in the preceding 6 months and levels of follicle-stimulating hormone (FSH) in the postmenopausal range. Rates were compared with the use of conditional logistic regression. Secondary end points included pregnancy outcomes and disease-free and overall survival.

Results

At baseline, 218 patients were eligible and could be evaluated. Among 135 with complete primary end-point data, the ovarian failure rate was 8% in the goserelin group and 22% in the chemotherapy-alone group (odds ratio, 0.30; 95% confidence interval [CI], 0.09 to 0.97; two-sided P=0.04). Owing to missing primary end-point data, sensitivity analyses were performed, and the results were consistent with the main findings. Missing data did not differ according to treatment group or according to the stratification factors of age and planned chemotherapy regimen. Among the 218 patients who could be evaluated, pregnancy occurred in more women in the goserelin group than in the chemotherapy-alone group (21% vs. 11%, P=0.03); women in the goserelin group also had improved disease-free survival (P=0.04) and overall survival (P=0.05).

Conclusions

Although missing data weaken interpretation of the findings, administration of goserelin with chemotherapy appeared to protect against ovarian failure, reducing the risk of early menopause and improving prospects for fertility. (Funded by the National Cancer Institute and others; POEMS/S0230 ClinicalTrials.gov number, NCT00068601.).

Premature menopause is a serious long-term side effect of chemotherapy. We evaluated long-term pregnancy and disease-related outcomes for patients in S0230/POEMS, a study in premenopausal women with stage I-IIIA estrogen receptor-negative, progesterone receptor-negative breast cancer to be treated with cyclophosphamide-containing chemotherapy. Women were randomly assigned to standard chemotherapy with or without goserelin, a gonadotropin-releasing hormone agonist, and were stratified by age and chemotherapy regimen. All statistical tests were two-sided. Of 257 patients, 218 were eligible and evaluable (105 in the chemotherapy + goserelin arm and 113 in the chemotherapy arm). More patients in the chemotherapy + goserelin arm reported at least one pregnancy vs the chemotherapy arm (5-year cumulative incidence = 23.1%, 95% confidence interval [CI] = 15.3% to 31.9%; and 12.2%, 95% CI = 6.8% to 19.2%, respectively; odds ratio = 2.34; 95% CI = 1.07 to 5.11; P = .03). Randomization to goserelin + chemotherapy was associated with a nonstatistically significant improvement in disease-free survival (hazard ratio [HR] = 0.55; 95% CI = 0.27 to 1.10; P = .09) and overall survival (HR = 0.45; 95% CI = 0.19 to 1.04; P = .06). In this long-term analysis of POEMS/S0230, we found continued evidence that patients randomly assigned to receive goserelin + chemotherapy were not only more likely to avoid premature menopause, but were also more likely to become pregnant without adverse effect on disease-related outcomes.