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Studies Find Poorer Outcomes for Breast Cancer Patients with BRCA Gene Mutations (dateline January 9, 2001)


Women who test positive for genetic mutations of the BRCA1 (breast cancer gene 1) or BRCA2  (breast cancer gene 2) genes are at a higher than average risk of developing breast cancer. Recently, two studies have found that women with BRCA gene mutations who develop breast cancer may have poorer outcomes than other women with breast cancer. Thus, women who know they carry mutated forms of BRCA genes may wish to consider more aggressive breast cancer preventive measures and treatments.

Both of the studies were published in a December 2000 issue of the Journal of Clinical Oncology. The first study was conducted in France and involved 183 breast cancer patients who reported family histories of breast and/or ovarian cancer. A total of 40 of the 183 women were found to have BRCA1 gene mutations after undergoing genetic testing.

According to Dominique Stoppa-Lyonnet and her colleagues, the women with BRCA mutations were found to have larger breast cancer tumors with higher grades and more negative estrogen and progesterone receptors than the women without BRCA mutations. All of these factors can indicate that the cancers are aggressive and may be less responsive to treatment than smaller, low-grade cancers with positive hormone receptors. Consequently, in the study, the women with BRCA mutations had a lower rate of survival than the women without BRCA mutations.

In the second study, conducted in Canada, researchers studied 202 Ashkenazi Jewish women with invasive breast cancer and found that the women who had BRCA 1 or BRCA2 gene mutations were also more likely to have low levels of the p27Kip1 protein. Pierre O. Chappuis and his colleagues found a poorer rate of survival among the women with BRCA1/2 gene mutations or low levels of the p27Kip1 protein. Approximately 58% of the women with BRCA mutations were alive after five years compared to 82% of the women without BRCA mutations, and 68% of the women with low levels of p27Kip1 were alive after five years compared with 93% of the women with high levels of p27Kip1.

While the results of these studies need to be confirmed in larger clinical trials, the findings do indicate that women with BRCA gene mutations may want to take preventive options to either prevent breast cancer or detect the cancer early, when chances of survival are greater. These measures may include: more frequent breast cancer screenings, taking the drug tamoxifen for a period of five years, or considering prophylactic mastectomy (preventive breast removal).

Only approximately 5% of breast cancer cases are associated with BRCA gene mutations. All women are born with BRCA genes. When functioning normally, BRCA1 and BRCA2 genes help repair damage to DNA—a process that also prevents tumor development. In 1994, researchers discovered that women who carry mutations of BRCA1 or BRCA2 are at higher risk of developing both breast and ovarian cancer than women who do not have these genetic mutations.

Both men and women may inherit and pass on BRCA1 or BRCA2 mutations. According to the Mayo Clinic, families that typically pass on BRCA defects have the following characteristics:

  • Breast cancer in two or more close relatives, such as a mother and two sisters
  • Early onset of breast cancer in family members, often before age 50
  • History of breast cancer in more than one generation
  • Cancer in both breasts in one or more family members
  • Frequent occurrence of ovarian cancer
  • Eastern and Central European (Ashkenazi) Jewish ancestry, with a family history of breast and/or ovarian cancer (researchers have identified two types of BRCA1 mutations and one BRCA2 mutation that are especially prominent in this group)

Genetic testing is a controversial subject, and healthcare professionals recommend seriously considering the consequences of knowing the test results before deciding whether genetic testing is appropriate. Advantages to genetic testing include feelings of relief, the opportunity to try new treatments or preventive measures targeted toward BRCA mutation carriers, and taking more aggressive breast cancer preventive and/or treatment options if test results are positive. Disadvantages to BRCA gene testing include increased stress if the results are positive, telling family members that they may also carry the mutations, and facing potential difficulties with insurance providers if the testing is not conducted anonymously. Women who are considering genetic testing for BRCA gene mutations are encouraged to discuss the decision with a genetic counselor before undergoing testing.

To help detect breast cancer early when chances for successful treatment and survival are the greatest, all women are encouraged to practice monthly breast self-exams, receive regular clinical breast exams, and begin screening mammography at age 40:

  • All women between 20 and 39 years of age should practice monthly breast self-exams and have a physician performed clinical breast exam at least every three years.
  • All women 40 years of age and older should have annual screening mammograms, practice monthly breast self-exams, and have yearly clinical breast exams.
  • Women with a family history of breast cancer or those who test positive for the BRCA1 or BRCA2 mutations may want to talk to their physicians about beginning annual screening mammograms earlier than age 40, as early as age 25 in some cases.

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