Women who experience new-onset breast tenderness after starting postmenopausal hormone therapy with combined estrogen plus progestin may have a higher risk of breast cancer than women who do not experience breast tenderness. These results were published in the Archives of Internal Medicine.
As women reach menopause and beyond, more than 80% will experience symptoms such as hot flashes, night sweats, sleep disturbance, and vaginal dryness. postmenopausal hormone therapy that includes estrogen can relieve these symptoms, but the risks and benefits of hormone therapy must be carefully weighed.
In 2002, results from a large clinical trial conducted as part of the Women’s Health Initiative (WHI) reported that combined estrogen plus progestin increases the risk of breast cancer, heart disease, stroke, and blood clots. Women taking estrogen plus progestin had fewer fractures and were less likely to develop colorectal cancer, but for most women, these benefits were thought to be outweighed by the risks.
Combined hormone therapy has also been noted to cause breast tenderness in some women, but it’s been uncertain whether this breast tenderness is related to breast cancer risk.
To explore the relationship between new-onset breast tenderness during hormone therapy and risk of breast cancer, researchers evaluated information from the WHI trial of combined estrogen plus progestin. The study enrolled more than 16,000 women between the ages of 50 and 79. Half the women received combined hormone therapy and half received a placebo.
The current analysis focused on women who did not report breast tenderness at the start of the study. Information about new-onset breast tenderness was collected one year into the study.
- New-onset breast tenderness was reported by 36.1% of women in the hormone group and 11.8% of women in the placebo group.
- Among women in the hormone group, those who reported new-onset breast tenderness were 48% more likely to develop breast cancer than those who did not report new-onset breast tenderness.
- Among women in the placebo group, new-onset breast tenderness was not related to risk of breast cancer.
These results suggest new-onset breast tenderness during postmenopausal hormone therapy with combined estrogen plus progestin may indicate an increased risk of breast cancer.
Reference: Crandall CJ, Aragaki AK, Chlebowski RT et al. New-onset breast tenderness after initiation of estrogen plus progestin therapy and breast cancer risk. Archives of Internal Medicine. 2009;169:1684-1691.