AACR: Familial Breast Cancer Risk for Black Women Hits Younger and Harder

LOS ANGELES, April 17 -- An African-American woman whose mother or sister was diagnosed with breast cancer before age 50 has triple the likelihood that she will be diagnosed with the malignancy before age 45, researchers here reported.

The familial breast cancer risk for black women is similar to that of white women, but black women are more likely to develop breast cancer at a younger age and the cancers are often more aggressive, said Boston University epidemiologist Julie R. Palmer, Sc.D., at the American Association for Cancer Research meeting.

The take-home message for physicians, she said, is simple. That message is to ask young African-American women -- those in the 20s, 30s, and 40s--about family history of breast cancer, she said.

"The risk associated with having a mother or sister with breast cancer has been well recognized for white women, but we have not previously assessed the family history risk for African American women,? she said, discussing findings from the 59,000-participant Black Women's Health Study.

They were recruited by questionnaires sent in March 1995 to 400,000 subscribers of Essence magazine as well as members of the National Education Association and the Black Nurses Association. A total of 59,000 women ages 21 to 69 completed the questionnaires.

Dr. Palmer said the participants are unique in that they are significantly younger than populations in many large observational studies. At enrollment 83% of the participants were younger than 50, and 56% were younger than 40.

At baseline women were asked if they had a mother or sister diagnosed with breast cancer and the age -- younger than 50 or older than 50 -- at which that diagnosis was made.

In 1999 the participants were asked about breast, colon, lung, and prostate cancer for first- and second-degree relatives.

After enrollment women were followed with postal questionnaires every two years, and with telephone calls to nonrespondents. The average follow-up at each questionnaire cycle was 80%, she said.

Breast cancer diagnoses (99.4%) were verified by medical records, pathology reports and death certificates. "Because of the high confirmation rate, self-reported cases of breast cancer were included as cases even if medical records could not be obtained," Dr. Palmer said.

Among the findings:

• From 1995 through 2005, there were 1,063 incident breast cancers.
• 873 cancers were diagnosed in women with no family history of breast cancer.
• 190 cancers were diagnosed in women with a mother or sister who had breast cancer (incidence ratio 1.79 95% CI, 1.53-2.10).
• Eleven breast cancer were diagnosed in women with two first-degree relatives with breast cancer (incidence ratio 2.31 95% CI 1.27-4.19).
• Among women younger than 45 with a first-degree relative who was diagnosed before are 50 the incidence ratio was 3.04 (95% CI 2.12-4.36).
• A family history of lung, prostate, or colon cancer was not associated with increased risk of breast cancer.

Dr. Palmer said the study was limited by its reliance on self-reported family history and the lack of information on BRCA-1 and BRCA-2 status.