Racial disparity in cancer rates and outcomes may be driven by genetics as well as socioeconomic factors, U.S. researchers said on Sunday.
Minorities are much more likely to develop and die from cancer than the general U.S. population, with previous research pointing to lack of health insurance, poverty, cultural barriers, and limited access to good medical care as causes.
“What is emerging now is a science of health disparities -- biological factors, genetic factors that can enhance the aggressiveness of cancer are being documented,” said Carlos Casiano, a professor in microbiology and molecular genetics at Loma Linda University in California.
A study presented here at the annual meeting of the American Association for Cancer Research found that genes may predispose African American women, who have a higher risk of dying from breast cancer, to more aggressive breast cancer than white women.
Researchers at Windber Research Institute in Pennsylvania and Walter Reed Army Medical Center in Washington, D.C., said their preliminary research identified two genes found in normal breast tissue that may promote breast cell growth in African Americans.
Using technology to examine large numbers of genes at once, researchers examined samples of healthy breast tissues from 26 black women and 22 white women. They found that two genes — one involved in cell division and growth and another involved in cellular energy production —were more active in African American women.
“Both conditions could promote cell growth .... making African American women more prone to developing breast cancer at a younger age,” said Lori Field, a postdoctoral fellow at Windber.
Breast cancer is the second-leading cause of cancer death among U.S. women, after lung cancer. More than 200,000 people are diagnosed and another roughly 40,000 die from it each year, according to the American Cancer Society.
In another study, National Cancer Institute researchers compared variations in a gene responsible for a protein involved in inflammation and immunity in colon cancer patients and people without colon cancer. They found that four of the variations were associated with a significant increase in colon cancer risk in African Americans, but not in Caucasians.
The researchers said they are working to validate the findings.