January 26, 2009

Preventive Mastectomies For Breast Cancer Survivors

An increasing number of female breast cancer survivors who suffered cancer in only one breast are opting to have the other one surgically removed in an effort to avoid the development of any future tumors.

Doctors say women diagnosed with cancer in one breast are at heightened risk for developing cancer in the other breast as well, yet researchers have struggled to determine which women are at highest risk of such an outcome.

U.S. researchers have identified three factors that make cancer in the other breast much more likely, based on a study involving 542 women with breast cancer.

Those three high-risk factors include having more than one tumor in the same breast when the initial cancer is diagnosed; having invasive lobular breast cancer, which begins in the milk-producing glands called lobules rather than in the milk ducts, and then invades surrounding tissues; and having a high score in the so-called Gail model that calculates breast cancer risk and considers things such as age at first menstrual period, age when first child was born and whether close relatives like mother or sister had the disease.

Dr. Kelly Hunt of the University of Texas M.D. Anderson Cancer Center in Houston, who led the study, said not all patients are equal in the risk for cancer in the other breast.

"Perhaps we can help patients to really more carefully understand their risk and make decisions in a more informed way," Hunt told Reuters.

Statistics from the American Cancer Society show that breast cancer is the leading cause of cancer death among women worldwide, with an estimated 465,000 dying annually. About 1.3 million women are diagnosed with breast cancer each year.

Many women see a contralateral prophylactic mastectomy"”where a woman may have the other breast removed before any sign of cancer appears"”as a potentially life-saving move.

For women who had the three risk factors identified in the study, such surgery may be a rational choice, researchers wrote in the study published in the journal Cancer.

The women in the study had both their breasts removed between 2000 and 2007.

Doctors typically are cautious about recommending such a step, Hunt said. "It's an irreversible thing, obviously. It's a pretty drastic procedure."

The study noted that a woman's race did not help determine risk of developing cancer in the future in her other breast. Nor did the hormone receptor status of the cancer.

Tumors in the breasts are tested for estrogen and progesterone receptors, which are proteins on the outside of a cell that can bind to chemicals, hormones or drugs traveling through the blood. Some tumors, for instance, are estrogen-receptor positive.

It is still unclear as to whether mutations in the genes called BRCA1 and BRCA2 that raise the risk of breast cancer also raise the risk of having cancer later develop in the initially unaffected breast.

These mutations or a strong family history of breast cancer prompt many women to undergo preventive mastectomies even before any tumor has developed in either breast.


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