MINNEAPOLIS / ST.PAUL (Oct. 23, 2007)—University of Minnesota Cancer Center researchers have found that the use of contralateral prophylactic mastectomy (CPM)—surgery to remove both breasts when cancer has been diagnosed in one breast—more than doubled in the United States between 1998 and 2003. The researchers say more understanding is needed about why some women choose CPM surgery, especially since most of them may not need it. The risk of cancer spreading to other parts of the body is greater than the risk of it spreading to the other breast.

This is the first study to determine the use of CPM surgery, often also called double mastectomy, on a national level. Todd Tuttle, M.D., chief of surgical oncology and a researcher with the University of Minnesota Medical School and Cancer Center, led the research team on this study. Their findings are described in an article titled "Increasing Use of Contralateral Prophylactic Mastectomy for Breast Cancer Patients: A Trend Toward More Aggressive Surgical Treatment," published online October 22, 2007 in the Journal of Clinical Oncology.

The University of Minnesota cancer researchers used the National Cancer Institute's Surveillance, Epidemiology, and End Research (SEER) public-use database to review the rates and trends of CPM surgery of patients diagnosed with cancer in one breast from 1998 through 2003. They found that during the six-year period, 152,755 women were diagnosed with stage I, II, or III breast cancer. Of those women, 59,460 had a single mastectomy and 4,969 women who could have had a single mastectomy chose instead to have CPM surgery. The researchers noted that the use of CPM surgery increased from 4.2 percent in 1998 to 11 percent in 2003. They found that women choosing CPM surgery were younger, non-Hispanic whites, and had lobular breast cancers, or a previous cancer diagnosis.

Tuttle says that while CPM surgery reduces the risk of cancer in the other breast, the surgery is also more aggressive and irreversible, and "most patients will not experience any survival benefit."

According to Tuttle, women who have the BRCA1 and BRCA2 genetic mutation and have been diagnosed with cancer in one breast have a higher risk of developing cancer in the other breast. Other women at higher risk for cancer in the other breast include those who are diagnosed at a younger age, have a family history of breast cancer, have particular types of breast cancer, and have had radiation treatment to the chest.

But he points out that for most women with cancer in one breast, "the spread of the cancer to other parts of the body is greater than developing cancer in the other breast. The annual risk of cancer developing in the other breast is about 0.5 percent to 0.75 percent."

Tuttle thinks that fear coupled with increased public awareness of the genetics of breast cancer and increased testing of women for the BRCA1 and BRCA2 genes have led to increased use of CPM surgery.

"Admittedly, awareness of breast cancer and its genetics is very important," Tuttle says. "However, CPM surgery may not always be necessary. We need to understand why an increasing number of women who are diagnosed with cancer in one breast opt for CPM surgery so that we can better counsel them about their risks for cancer in the other breast and the other treatment options available to them."

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A grant from the National Cancer Institute funded this research study. Colleagues working with Tuttle included Elizabeth Habermann, M.P.H., Erin Grund, Todd Morris, M.D., Ph.D., and Beth Virnig, Ph.D., M.P.H., all with the University of Minnesota.

The Academic Health Center is home to the University of Minnesota's six health professional schools and colleges as well as several health-related centers and institutes. Founded in 1851, the University is one of the oldest and largest land grant institutions in the country. The AHC prepares the new health professionals who improve the health of communities, discover and deliver new treatments and cures, and strengthen the health economy.

The University of Minnesota Cancer Center is part of the University's Academic Health Center. It is designated a Comprehensive Cancer Center by the National Cancer Institute. To learn more about the Cancer Center and cancer, call 612-624-2620 or toll-free in Minnesota, Iowa, Wisconsin, and the Dakotas at 1-888-CANCER MN (1-888-226-2376); or visit www.cancer.umn.edu.

Media Contacts:

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