REVIEW QUESTION

Is adding ovarian function suppression (OFS) to hormone-positive early breast cancer treatment beneficial and safe for premenopausal women?

TYPE OF REVIEW

A systematic review of 15 studies involving 11,538 women with hormone-positive early breast cancer.

RELEVANCE FOR NURSING

Early breast cancer is defined as disease within the breast, with or without lymph node involvement, with no distant metastasis. Breast cancer cells may be hormone negative or hormone positive; specifically, estrogen receptor positive and/or progesterone receptor positive. Breast cancer cells that are hormone positive can respond to OFS, which stops the hormones that fuel the cancer and has been used as an adjunct to other treatments, including chemotherapy, surgery, and/or radiation. Methods of OFS include oophorectomy, radiation-induced ovarian ablation, and luteinizing hormone-releasing hormone antagonists.

People who have been diagnosed with breast cancer report a great need for information about treatment and managing side effects. Oncology nurses, particularly breast cancer nurses, have specialized knowledge in this area, and all nurses will at some time care for people who have had a breast cancer diagnosis. Because breast cancer is rare in men, this article focuses on premenopausal women with hormone-positive early breast cancer.

CHARACTERISTICS OF THE EVIDENCE

The objective of this review was to investigate the effects of all methods of OFS on hormone-positive early breast cancer in premenopausal women. Primary outcomes were overall survival and disease-free survival (recurrence). Secondary outcomes included second malignancy, contralateral breast cancer, toxicities, quality of life, and compliance with treatment.

Interventions of interest were any form of OFS. Studies were included if they compared OFS with observation, OFS plus chemotherapy with chemotherapy, OFS plus tamoxifen with tamoxifen, and OFS plus chemotherapy plus tamoxifen with chemotherapy plus tamoxifen.

Cochrane's risk of bias assessment was applied to the included studies. Frequencies and proportions were reported for most toxicities because of the paucity of the data. Quality of life data were reported qualitatively. The GRADE approach was used for the quality of the evidence and the strength of recommendations.

Fifteen studies involving 11,538 women were included. Compared with treatment that didn't include OFS, OFS treatment improved survival and reduced disease recurrence. OFS probably reduced risk of contralateral breast cancer, but not of a second malignancy. OFS increased the risk of hot flashes but not of other toxicities. The impact on quality of life of OFS compared with no OFS varied, though only five studies assessed this. When reported, compliance with treatment was high (78% or greater).

BEST PRACTICE RECOMMENDATIONS

The authors recommend the use of OFS in premenopausal women with hormone-positive early breast cancer. However, because OFS use appears to increase the risk of hot flashes, the authors note that individual women's risk-benefit profile should be considered in deciding whether to use it.

The fact that psychosocial and emotional support is an essential part of cancer care was emphasized by many women in both the OFS and non-OFS groups reporting an increased level of anxiety. Similarly, quality of life symptoms including gynecological symptoms, vaginal dryness, decline in sexual interest, bone and joint pain, and weight gain were reported in both the OFS and non-OFS groups.

The finding of an increase in hot flashes is significant. For women who are taking OFS and experiencing this side effect, there are recent evidence-based guidelines to manage hot flashes that do not interfere with treatment protocols.

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