UCSF doctor studies Jewish links to breast cancer

Do Jewish women have an increased risk of getting breast cancer?

Not necessarily. Dr. Laura Esserman, one of the nation's foremost experts on "breast cancer and the Jewish connection," addressed this complex topic in a recent talk.

A surgeon and the director of the Breast Care Center at UCSF Medical Center, Esserman discussed some of the latest findings in research on the possible connection between the disease and women of Jewish descent. She spoke last month at the Jewish Community Center of San Francisco, as part of its Women's Series.

"What is breast cancer? That's the million dollar question," Esserman told the gathering. "If we knew how it worked, we wouldn't be here today."

Breast cancer "is not uncommon," Esserman said. According to UCSF research, an estimated one in eight women, or 12.5 percent of women in the United States, will develop breast cancer sometime during their lifetime. American women have a 3.5 percent, or 1 in 29 risk, of dying from the disease.

The genes predisposing a woman to breast cancer are found in as many as 2 percent of the Ashkenazi Jewish population, (those whose ancestors came from Central or Eastern Europe).

According to Esserman, there are two principal genes, known medically as BRCA1 and BRCA2, that when abnormal or mutated, indicate an inherited susceptibility to breast and ovarian cancers. These genes together account for 40 to 50 percent of all inherited cases of breast cancers.

Recent studies examining the risk of breast and ovarian cancers among Ashkenazi Jews have found that a woman with the BRCA1 and BRCA2 mutations has about a 56 percent chance of getting breast cancer by the age of 70.

Currently, it is impossible to predict the percentage of carriers who will develop breast cancer, much less one woman's risk, Esserman noted. Prevalence of BRCA1 in the general population ranges from 0.4 percent to 0.2 percent, and BRCA2 is even less common.

Roughly 5 to 10 percent of breast cancers are believed to be inherited, Esserman reported. She also cautioned that hereditary breast cancer occurs at younger ages than non-hereditary cases, indicating that early screening and self-examinations might be useful for those women in a high-risk group.

In these instances, the cancer is more likely to be bilateral, occurring in both breasts, and often appears in multiple family members over three or more generations. It includes women from the maternal and paternal side of the family, Esserman told attendees.

In addition to the BRCA1 and BRCA2 genes, breast cancer is caused by a myriad of factors, including lifestyle or environmental factors. Family history of breast cancer is associated with an increased risk, especially a history of breast cancer in a mother, sister or daughter, Esserman said.

A women's age when bearing children also may come into play. "The Bay Area has a large population of educated women," Esserman said. "Most women have children after 30 in the Bay Area. As a result, we have more women in the San Francisco Bay Area with breast cancer than in many other areas of the country."

Although women can adopt lifestyle habits to lower their risk, some will get breast cancer no matter what. "Some women that I have diagnosed with breast cancer say, 'I had all my children by the age of 19 and have had a vegan diet all my life. What did I do wrong?'

"There are some things that are just bad luck," Esserman remarked.

Although the isolation of the two genes linked to hereditary breast cancer has led to the development of screening, Esserman said that even among women with breast cancer in their families, the tests for BRCA1 and BRCA2 could be negative 90 percent of the time, unless a mutation has been previously identified in the family.

To determine if they should be tested for BRCA1 and BRCA2 mutations, Esserman urged women to carefully consider a variety of factors. "Do you come from a large or small family? Are you the only one in your family who has breast cancer? What was the age that the breast cancer was detected?

"If you don't have a family history and you don't have breast cancer, it doesn't help to be tested. You want to know if the person with cancer has the mutation."

For women with the mutation, Esserman recommended counseling and early breast-cancer screenings, including annual mammography and clinical breast examination beginning at ages 25 to 35.

One of the most powerful tools in helping detect and treat breast cancer, Esserman concluded, is information and education.