Study Indicates Targeted Strategies Needed to Find, Prevent and Treat Breast Cancer among Mexican-Origin Women
Half of study participants had disease diagnosed before age 50
MD Anderson News Release 09/01/10
Specific prevention and education strategies are needed to address breast cancer in Mexican-origin women in this country, according to a study at The University of Texas MD Anderson Cancer Center, which was published online in the journal Cancer.
Among the Mexican-origin women with breast cancer who were surveyed, half were diagnosed before age 50, years earlier than the national average for non-Hispanic white women. This puts them outside the recently released U.S. Preventive Task Force guidelines that recommend screenings, including mammograms, begin at 50 for the general population. The guidelines have been controversial, and MD Anderson opted to continue to recommend screening beginning at age 40.
"Under the revised Task Force guidelines, up to half of Mexican-origin women with breast cancer may be undiagnosed or diagnosed in late stages, possibly increasing disparities in rates of breast cancer mortality," said Patricia Miranda, Ph.D., a Kellogg Health Scholar post-doctoral fellow in the Center for Research on Minority Health in the Department of Health Disparities Research at MD Anderson and the study's lead author. "Hispanic women are not recognized in the guidelines as a high-risk group, and we would like to see that decision revisited."
One-Size-Fits-All Approach Falls Short
Breast cancer is the leading cause of death among Hispanic women in the United States. Previous studies have shown they are more likely to be diagnosed with advanced breast cancer and 20 percent more likely to die from the cancer than non-Hispanic white women.
Hispanics are the nation's largest and fastest growing minority group. According to the American Community Survey, more than 45 million Hispanics live in this country. By 2050, the population - which has the lowest rate of insurance coverage - is expected to reach 132 million.
"As the new national health care policy is implemented, if a one-size-fits all screening recommendation is implemented as the Task Force recommends, we fear a huge number of breast cancer cases won't be picked up at an early stage, especially with the growth of the Hispanic population in this country," said Melissa Bondy, Ph.D., professor in the Department of Epidemiology and senior corresponding author.
The study, which is among the first to use a non-clinical, population-based sample to examine the risk of breast cancer in this group, identified 714 Hispanic women in the Houston area from MD Anderson's Mano a Mano Mexican-American Cohort Study: 119 with breast cancer and 595 without cancer.
Several factors were compared including:
- Age at diagnosis
- Family history of breast cancer
- Marital status, number of children and education
- Health insurance status
- Language acculturation (ability to speak English)
- Country of birth (U.S. or Mexico)
Family History, Acculturation Raise Risk
Women at highest risk for breast cancer - 2-1/2 times other women surveyed - had a family history of the disease, spoke English well and were born in Mexico.
The strongest risk factor was family history, which increased odds fourfold and was found to be true of 15 percent who had breast cancer. This indicates that women with a strong family history of breast cancer should receive earlier and more frequent screening, Bondy said.
The role of acculturation was striking too. Women who were born in Mexico and spoke English well had 2-1/2 times the risk of women born in Mexico who did not.
Single women were almost twice as likely as married women to develop breast cancer, and women without insurance were 1-1/2 times more likely than those with insurance to be diagnosed. Women who do not have insurance are less likely to be screened.
Although the study is fairly small, researchers believe it shows the need for clear action on several fronts.
"Going forward, we believe it's essential to create education programs specifically for this population, especially if any of the screening guidelines change," Miranda said.
In addition, the study recommends assistance with acquiring health insurance, which may increase access to screening and early detection, and working with affected communities to help formulate policy agendas.
More Research Planned
Although Hispanics are the fastest growing group in the country, they are markedly under-represented in medical research. MD Anderson, which has been studying Mexican-American health through the Mano A Mano study for 10 years, is involved in a major study of Hispanic women in Mexico, Arizona and Texas.
"We are looking at reasons these women are getting breast cancer earlier and tend to develop later stage breast cancer," Bondy said. "We're hoping to find answers that will help save lives."
Co-authors with Miranda and Bondy on the study include: Anna Wilkinson, Ph.D.; Carol Etzel, Ph.D. and Renke Zhou; all of MD Anderson's Department of Epidemiology, and Lovell Jones, Ph.D., director of the Center for Research on Minority Health in the Department of Disparities Research at MD Anderson; and Patricia Thompson, Ph.D. from the University of Arizona, Arizona Cancer Center.
The research was supported in part by the Kellogg Health Scholars Program, the National Cancer Institute, the Caroline W. Law Fund for Cancer Prevention, the Duncan Family Institute for Cancer Prevention and Risk Assessment, and the National Center on Minority Health and Health Disparities. In addition, funds collected pursuant to the Comprehensive Tobacco Settlement of 1998 and appropriated by the 76th legislature to MD Anderson provided funding. 09/01/10