Study: Tamoxifen not likely to prevent many breast cancers in at-risk women

September 27, 2004

CHAPEL HILL -- Research has shown that the drug tamoxifen citrate not only helps prevent recurrence of breast cancer, but it also can keep the deadly disease from occurring in the first place in some women.

But a new University of North Carolina at Chapel Hill study indicates it's unlikely that tamoxifen will ever be given widely to women to prevent breast cancer. That's because the drug would avert only a maximum of 6 percent to 8.3 percent of breast tumors in eligible women, UNC School of Medicine researchers have found.

"Our calculations showed that tamoxifen's possibly harmful side effects, including blood clots and stroke, would rule out some 90 percent of women who might benefit from taking it each day," said Dr. Russell P Harris, associate professor of medicine at UNC.

A report on the study appears in the latest issue of the Archives of Internal Medicine.

Besides Harris, a member of UNC's Lineberger Comprehensive Cancer Center, authors are principal investigator Dr. Carmen L. Lewis, assistant professor of medicine at UNC; Dr. Linda S. Kinsinger, assistant director of the VA Center for Health Promotion and Disease Prevention; and Robert J. Schwartz, a computer programmer at UNC's Cecil G. Sheps Center for Health Services Research.

The study involved having 605 women, ages 40 to 69, in 10 general internal medicine practices in North Carolina, fill out questionnaires about their health and family histories of breast cancer. Then, using a proven formula for assessing breast cancer incidence and factoring in the women's responses, researchers determined the expected number of cases that would occur over the next five years.

They found that only a relatively small number of women in primary care practices would be eligible for the chemopreventive therapy because of existing conditions such as high blood pressure and diabetes and other risk factors, Harris said. Since the majority of women never develop breast cancer anyway, the percentage of actual cancers prevented would be small.

"Screening mammography, which is useful, is not the whole answer to preventing breast cancer deaths, and our new work shows that tamoxifen won't be either," he said. "On the other hand, in a message to the research community, tamoxifen has shown us that if we can find other chemopreventive agents that don't have all the side effects, then we could have greater success and save more lives."

Tamoxifen works in women by blocking what's known as the estrogen receptor that allows the hormone to work, the physician said. Most breast cancer development is dependent on estrogen.

Limitations of the research were that the number of women in each age category of the overall group were small, and black women, women with less education and those with no health insurance were not well represented in the sample, Harris said. Similar studies with larger numbers of subjects would help confirm the results.
-end-
The National Cancer Institute, UNC's Lineberger Comprehensive Cancer Center and the Agency for Healthcare Research and Quality supported the investigation.

University of North Carolina at Chapel Hill

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.