Chemotherapy can cure early-stage breast cancer, but it can also result in premature menopause, a highly unwelcome long-term side effect. In the final results of its investigation, the Southwest Oncology Group (SWOG)'s Prevention of Early Menopause Study (POEMS) reports a potential solution: women who receive goserelin (Zoladex®, AstraZeneca) along with standard chemotherapy for hormone-receptor negative breast cancer increase their chances of becoming pregnant without negatively impacting their cancer treatment outcome.
For the POEMS study, premenopausal women with stage I–IIIA estrogen receptor-negative, progesterone receptor-negative breast cancer received a standard treatment of cyclophosphamide-containing chemotherapy; in addition, 105 of the 218 eligible and evaluable patients participating in the study received goserelin, a gonadotropin-releasing hormone agonist.
The results, published in the Journal of the National Cancer Institute, revealed that more patients receiving goserelin along with chemotherapy reported at least one pregnancy over the course of a five-year follow-up period than did those receiving chemotherapy alone (23.1% vs 12%). Moreover, adding goserelin to the chemotherapy regimen improved disease-free survival (88% vs 79%) and overall survival (92% vs 83%), although these results did not reach statistical significance.
"These five-year follow-up results confirm our initial findings," commented the study's lead investigator, Halle Moore, MD, Associate Professor of Medicine at the Cleveland Clinic. "Goserelin protects the ovaries from the effects of chemotherapy, reducing the risk for early menopause. By getting these injections, more women became pregnant without negatively affecting their health or their chances of surviving their cancer."
The POEMS study was a collaborative effort involving SWOG and two additional research groups, ECOG-ACRIN Cancer Research Group and the Alliance for Clinical Trials in Oncology, all of which are part of the National Cancer Institute's National Clinical Trials Network (NCTN). Patients were able to participate in the trial internationally thanks to the International Breast Cancer Study Group, which includes the Australia New Zealand Breast Cancer Trials Group.
The initial results of POEMS have already impacted treatment of hormone-receptor negative breast cancer by prompting changes in the National Comprehensive Cancer Network (NCCN) Clinical Practice Guidelines for Oncology and the St. Gallen Consensus Conference guidelines. Both of these sources now reference the use of goserelin for younger women who hope to protect ovarian function during chemotherapy for breast cancer.
Dr. Moore commented on the importance of the study's results: "Cancer researchers set out to change the standard of care in order to improve, or lengthen, people's lives. Our final results show a means to improve quality of life for young women with hormone-receptor negative breast cancer. If they want to be mothers, they can improve their chances safely and effectively. I'm proud of this result, and our international team."
For More Information
Moore HCF, Unger JM, Phillips KA, et al (2018). Final analysis of the Prevention of Early Menopause Study (POEMS)/SWOG Intergroup S0230. J Natl Cancer Inst. [Epub ahead of print] DOI:10.1093/jnci/djy185