Menopausal women who experience the onset of new breast tenderness after taking combination estrogen-progestin hormone therapy have a 33 percent greater risk of subsequent breast cancer than women who do not experience the tenderness, a new study found.
Researchers at UCLA’s Jonsson Comprehensive Cancer Center say in contrast, women taking estrogen replacement alone and who experienced new onset breast tenderness have no higher risk for breast cancer down the road.
The findings were surprising, said the study’s first author Dr. Carolyn Crandall, a professor of general internal medicine and a scientist with UCLA’s Jonsson Comprehensive Cancer Center. “Who would have guessed the same symptom in two sets of women taking different hormone therapies could mean something different.”
Crandall says it’s too early to call for an increase in the frequency of clinical breast exams and mammograms in women on hormone therapy based on these studies. However, a woman on combination hormone therapy who experiences new onset breast tenderness should be vigilant about getting her regular clinical breast exams and mammograms.
“We don’t want to incite panic because breast cancer is rare in women taking hormone therapy, but the point is that women are terrified of getting breast cancer as a result of menopausal hormone therapy,” Crandall said.
“Where I think this study would be important is for women already on either combination hormone therapy or estrogen alone. If they do develop breast tenderness, it would be good for them to know the results of this study and to consider discussing them with their physician.”
The study was published early online, and appears in the Nov. 17, 2011 peer-reviewed journal Breast Cancer Research and Treatment.
Crandall has done numerous breast cancer studies. A separate study published last month, found that the new onset of breast tenderness was much more pronounced after initiation of estrogen and progestin therapy than in women getting estrogen therapy alone. The association between new onset breast tenderness and changes in breast density also was more pronounced in the women getting the combination hormone therapy.