Weight gain may increase risk of breast cancer in postmenopausal women

July 11, 2006

Weight gain, particularly after menopause, is associated with an increased risk of breast cancer in women, according to an article in the July 12 issue of JAMA.

Background information in the article indicates that weight loss after menopause lowers circulating estrogen hormones in women, and because estrogen is directly related to breast cancer, weight loss is thought to decrease risk of the disease. Studies show that weight gain since early adulthood is associated with increased breast cancer risk in postmenopausal women, particularly those not taking postmenopausal hormones. However, weight changes in middle-aged to older women (50 years and older) has been studied less extensively.

A. Heather Eliassen, Sc.D., of Brigham and Women's Hospital and Harvard Medical School, Boston, and colleagues analyzed data within the Nurses' Health Study to determine the association between weight change and the risk of breast cancer among postmenopausal women. The researchers assessed weight change for two different periods--since 18 years of age and since menopause. A total of 87,143 postmenopausal women (ages 30 to 55 years) were followed up for up to 26 years to analyze weight change since age 18. Weight change since menopause was assessed among 49,514 women (followed up for up to 24 years).

Women who gained about 55 pounds or more since age 18 were at a 45 percent increased risk of breast cancer, compared with those who maintained their weight, with a stronger association among women who have never taken postmenopausal hormones. Women who gained about 22 pounds or more since menopause were at an 18 percent increased risk of breast cancer. Those who lost about 22 pounds or more since menopause (and kept the weight off) and had never used postmenopausal hormones were at a 57 percent lower risk of breast cancer than those who simply maintained their weight. The researchers concluded that 15 percent of the study's breast cancer cases may be attributable to weight gain of 4.4 pounds or more since age 18 and 4.4 percent of the cases may be attributable to weight gain of 4.4 pounds or more since menopause.

"These data suggest that weight gain during adult life, specifically since menopause, increases the risk of breast cancer among postmenopausal women, whereas weight loss after menopause is associated with a decreased risk of breast cancer," the authors write. "Women should be advised to avoid weight gain both before and after menopause to decrease their postmenopausal breast cancer risk. (JAMA. 2006; 296: 193 - 201. Available pre-embargo to media at www.jamamedia.org.)
-end-
Editor's Note:
This study was supported by a research grant from the National Cancer Institute. Dr. Eliassen was supported by a training grant from the Department of Defense and Cancer Education and a Career Development grant from the National Cancer Institute. Co-author Dr. Colditz was supported in part by a Cissy Hornug Clinical Research Professorship from the American Cancer Society.

The JAMA Network Journals

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.