Postmenopausal hormone replacement therapy linked to increased risk for certain types of rarely occurring breast cancer

June 08, 1999

CHICAGO --- Using hormone replacement therapy during menopause increases a woman's risk for developing some types of breast cancer that occur rarely, but not the more commonly occurring ductal carcinoma that remains confined to the site of origin or invasive ductal or lobular cancer.

These are the findings of a study by researchers from Northwestern University Medical School and the Mayo Clinic that appears in the June 9 issue of The Journal of the American Medical Association.

Susan M. Gapstur, assistant professor of preventive medicine, and Monica Morrow, M.D., professor of surgery, of Northwestern, and Thomas A. Sellers, of the Mayo Clinic, studied over 37,100 postmenopausal women in the Iowa Women's Health Study to determine if use of hormone replacement therapy was associated with subsequent risk for specific types of breast cancer.

"We observed a positive, dose-response relationship between duration of postmenopausal hormone use and incidence of breast cancer with a favorable prognosis; this relationship appeared to be stronger for current users compared with past users," the researchers said.

Conversely, among the women studied, the incidence of ductal carcinoma in situ and invasive ductal or lobular carcinoma was not related to ever having used hormones. However, the data suggest a modest increased risk for invasive ductal or lobular carcinoma among women who, at the beginning of the study, reported current hormone replacement therapy use for five or fewer years.

The authors reported that the risk for favorable breast cancers for women who ever used hormone replacement therapy for five or fewer years was 1.8 times greater than for women who never used hormone replacement therapy. Women who used hormone replacement therapy for more than five years had 2.6 times the risk.

The association of hormone replacement therapy with breast cancer is controversial. According to the researchers, despite the positive effect of hormone replacement therapy on reducing menopausal symptoms, lowering risk for osteoporosis and a potentially beneficial effect on primary prevention of coronary heart disease, concerns about breast cancer cause many women not to take estrogens. A considerable amount of epidemiologic data supports a modest increase in risk for breast cancer with long-term hormone use.

The researchers said that although there may be several possible reasons for a specific risk association of hormone replacement therapy with favorable breast cancers, increased medical surveillance cannot explain this observation since these tumors are not precursor lesions for other types of invasive breast cancers.

The authors agreed that further study is needed and that this research should explore more fully differences in the association between types of postmenopausal hormone use and breast cancer risk across tumor types.

They also noted that if hormone replacement therapy increases the risk for less commonly occurring tumors with a good prognosis, then the overall risks and benefits of hormone use in the population should be reexamined.
-end-


Northwestern University

Related Breast Cancer Articles from Brightsurf:

Oncotarget: IGF2 expression in breast cancer tumors and in breast cancer cells
The Oncotarget authors propose that methylation of DVDMR represents a novel epigenetic biomarker that determines the levels of IGF2 protein expression in breast cancer.

Breast cancer: AI predicts which pre-malignant breast lesions will progress to advanced cancer
New research at Case Western Reserve University in Cleveland, Ohio, could help better determine which patients diagnosed with the pre-malignant breast cancer commonly as stage 0 are likely to progress to invasive breast cancer and therefore might benefit from additional therapy over and above surgery alone.

Partial breast irradiation effective treatment option for low-risk breast cancer
Partial breast irradiation produces similar long-term survival rates and risk for recurrence compared with whole breast irradiation for many women with low-risk, early stage breast cancer, according to new clinical data from a national clinical trial involving researchers from The Ohio State University Comprehensive Cancer Center - Arthur G.

Breast screening linked to 60 per cent lower risk of breast cancer death in first 10 years
Women who take part in breast screening have a significantly greater benefit from treatments than those who are not screened, according to a study of more than 50,000 women.

More clues revealed in link between normal breast changes and invasive breast cancer
A research team, led by investigators from Georgetown Lombardi Comprehensive Cancer Center, details how a natural and dramatic process -- changes in mammary glands to accommodate breastfeeding -- uses a molecular process believed to contribute to survival of pre-malignant breast cells.

Breast tissue tumor suppressor PTEN: A potential Achilles heel for breast cancer cells
A highly collaborative team of researchers at the Medical University of South Carolina and Ohio State University report in Nature Communications that they have identified a novel pathway for connective tissue PTEN in breast cancer cell response to radiotherapy.

Computers equal radiologists in assessing breast density and associated breast cancer risk
Automated breast-density evaluation was just as accurate in predicting women's risk of breast cancer, found and not found by mammography, as subjective evaluation done by radiologists, in a study led by researchers at UC San Francisco and Mayo Clinic.

Blood test can effectively rule out breast cancer, regardless of breast density
A new study published in PLOS ONE demonstrates that Videssa® Breast, a multi-protein biomarker blood test for breast cancer, is unaffected by breast density and can reliably rule out breast cancer in women with both dense and non-dense breast tissue.

Study shows influence of surgeons on likelihood of removal of healthy breast after breast cancer dia
Attending surgeons can have a strong influence on whether a patient undergoes contralateral prophylactic mastectomy after a diagnosis of breast cancer, according to a study published by JAMA Surgery.

Young breast cancer patients undergoing breast conserving surgery see improved prognosis
A new analysis indicates that breast cancer prognoses have improved over time in young women treated with breast conserving surgery.

Read More: Breast Cancer News and Breast Cancer Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.