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.
Multiple population studies have shown that higher breast density is associated with a higher risk of breast cancer. In women with extremely dense breasts, the cancer risk can be four to six times higher than for women whose breasts are not dense, Crandall said in a statement.
For women who undergo menopause naturally, estrogen is typically prescribed along with progestin, a man-made replication of progesterone. This is because estrogen without progestin can increase the risk of uterine cancer. Women who undergo menopause as the result of a hysterectomy can take estrogen alone, according to the Mayo Clinic, which was not associated with the study.
Crandall and her team analyzed data from more than 27,337 women enrolled in the Women’s Health Initiative (WHI), the largest and longest randomized controlled trials of menopausal hormone therapy ever performed. Of the 27,337 women in the prospective study, 16,608 were on the combination therapy, while 10,739 were taking estrogen alone. Launched in 1991, the WHI consisted of a set of clinical trials and an observational study involving 161,808 healthy postmenopausal women.
To learn more about menopause, hormone replacement therapy and what to expect during your new phase of life, visit www.womenshealth.gov/menopause
Lynette Summerill, an award-winning writer and scuba enthusiast lives in San Diego, CA with her husband and beach-loving dogs. In addition to writing about cancer-related issues for EmpowHER, her work has been seen in newspapers and magazines around the world.
Breast Cancer Research and Treatment. Breast Tenderness and breast cancer risk in the estrogen plus progestin and estrogen-alone women’s health initiative clinical trials. Carolyn Crandall, Aaron Aragaki, Jane Cauley, Anne McTiernan, JoAnn Garnet, Anderson, Manson, Rowan Chlebowski, Published online 31 Oct. 2011. http://www.springerlink.com/content/n6x3130l2t61u884
UCLA Media Release. “Women on combo hormone therapy who have breast tenderness are at 33 percent greater risk of breast cancer than women on estrogen.” Kim Irwin. 17 Nov. 2011.
Mayo Clinic. Is Hormone Therapy Right For You. Published online 2010. Accessed 17 Nov. 2011 at:
Reviewed November 24, 2011
by Michele Blacksberg RN
Edited by Jody Smith