Black and White Women Share the Same Genetic Risk for Breast Cancer

TUESDAY, May 19, 2020 (HealthDay News) -- Black and white women share genes that increase the risk for breast cancer, a new study finds.

These genes include BRCA1, BRCA2 and PALB2, each of which is associated with a more than sevenfold risk of breast cancer. Women of both races also share four other genes linked with a moderately increased risk, according to researchers.

"This means that the multi-gene panels that are currently available to test women diagnosed with breast cancer or women at high risk due to their family history will be useful for African-American women," study co-author Julie Palmer said in a Boston University news release. She is director of the university's Slone Epidemiology Center.

For the study, the researchers compared data from more than 5,000 black women with breast cancer with nearly the same number of black women without the disease.

More than 7% of women with breast cancer had a mutation in one of the genes, compared with 2% of the other women.

The study also revealed that more than 10% of breast cancer patients with no estrogen receptors (ER-negative breast cancer) had a gene mutation, compared with 5% of women with estrogen receptors (ER-positive breast cancer).

ER-positive indicates that the cancer cells may receive hormone signals that could promote their growth. This type of cancer can be treated with drugs that lower estrogen levels or block estrogen receptors, according to the American Cancer Society.

But hormone therapy drugs aren't helpful for ER-negative cases, which tend to be faster growing.

Study co-author Fergus Couch is professor of medical research at the Mayo Clinic in Rochester, Minn. He said the research also showed that mutations in the genes PALB2, RAD51C and RAD51D put African-Americans at increased risks of ER-negative breast cancer.

Palmer said the genetic findings can aid women who are weighing the best course of prevention and treatment.

"Depending on results of the testing and an individual's own weighing of pros and cons, a woman with a mutation in any of these genes may choose more aggressive screening for cancer, and women with mutations in the high-risk BRCA1 and BRCA2 genes may choose removal of her breasts and/or ovaries as a way to prevent initial breast cancer or recurrence," she said.

Palmer noted that breast cancer screening recommendations are sometimes different for black and white women.

"To the extent that the differences in recommendations are the result of misconceptions among clinicians about the prevalence of genetic mutations and associated risks in African-American women, awareness of our findings may serve to increase the proportion of African-American women who are offered testing," she said.

The findings were published online May 19 in the Journal of the National Cancer Institute.

More information

Learn more about breast cancer from the American Cancer Society.

SOURCE: Boston University, news release, May 19, 2020

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