How much of the health gap between Black and White Americans can researchers explain through differences in genetic make up? And what impact does the environment have on our health?
As a MacArthur Fellow, Dr. Olufunmilayo Olopade won $500,000 in unrestricted support for five years. Olopade continues to lead research efforts to understand the role our genes and environment play in the development and treatment of breast cancer in women at home and abroad.
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THE PUBLISHER'S POINT
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ER-negative Breast Cancer Tumors - A Middle Passage Survivor
Black women are less likely to get breast cancer than White women, but are more likely to get the disease when they are young and are much more likely to die from it. These facts puzzled Olopade and led to her groundbreaking Pan-African study.
Her discovery started on one of her biennial vacations to her birth country, Nigeria. In 1997, she began working with breast surgeon Dr. Adebarnowo at the University of Ibadan, her alma mater, by collecting and studying data on Nigerian women with breast cancer. (Olopade is continuing the study in the United States to further document the link between Black women at home and abroad.) The Nigerian study led to three crucial findings:
1. Tumors in African women are more likely to develop from a different set of cells in the breast that can turn into a more aggressive type of breast cancer.
2. Breasts tumors in African women are less likely to express a genetic marker that the breast cancer drug Herceptin attacks.
3. Eight in ten tumors in African women are estrogen receptor negative (ER-negative). This rendered the anti-cancer drugs that target female hormones within breast cancers useless.
“These ER-negative tumors are not sensitive to the female hormone estrogen and thus do respond to drugs, such as tamoxifen, that work by keeping the estrogen from reaching cancerous cells and stimulating growth. Because ER-negative breast cancer moves fast, physicians must catch it early. Without chemotherapy treatments most patients die within two years,” warns Olopade.
Research also shows that in Africa most breast-cancer cases occur around age 40, as opposed to the late 50s or 60s in the U.S. Most U.S. screening guidelines, based primarily on Caucasian data, recommend an annual mammogram beginning at 50. However, African Americans are more like their genetically related Continental sisters and are likely to get the disease between ages 40 and 50. “Black women,” Olopade says, “should first get screened around age 25, and those who are high-risk, for example, women with a family history of the disease - - even younger.”
BiDil - “The Black Drug?”
Hypertension and OppressionFor many years people assumed that genetics and psychosocial factors, like the affects of surviving oppression, predisposed African-Americans to high blood pressure. However, many came to this conclusion without looking at high blood pressure data for international Black populations.
Genetic Testing and HIV Management
Abacavir,a medication that doctors use to treat HIV, causes potentially life threatening allergic reactions in 2 to 9 percent of patients. Though “Blacks are less likely to have an allergic reaction,” explained Port of Harlem contributor Dr. Theo Hodge, Jr., “doctors should not depend upon race alone to determine whether to prescribe the medication.”
Studies show that patients who are allergic to Abacavir often posses within their genetic maps an area known as HLA-B*5701. Echoing Jackson’s concerns about equating race with genetics Hodge continued, “assumptions that a Black patient will not react to Abacavir are unacceptable. A blood test is now available to assess if this genetic area exists in individual patients.”
Looking Toward the FutureThe question remains: How much of the health gap between Black and White Americans can researchers explain through differences in genetic make up? And what impact does the environment have on our health? Jackson, who specializes in biological anthropology says, “In world history, the gene-environment interactions are consistently much more important than the naked genetics alone.”