Research showing breast cancer to be more aggressive in Mexican-American women has inspired a flurry of studies aimed at finding out why. On the surface, the clearest cause is genetics, a topic that was discussed at the American Association for Cancer Research's Science of Cancer Health Disparities Conference. Maria Elena Martinez, PhD, MPH, Professor in the Epidemiology and Biostatistics Division at the University of Arizona Mel and Enid Zuckerman College of Public Health, and colleagues recently reported on Mexican Americans' genetic susceptibility in women with breast cancer negative for estrogen receptors, progesterone receptors, and the human epidermal growth factor receptor 2 (HER2).
Dr. Martinez also moderated a news conference at the meeting, which was cosponsored by the National Cancer Institute and Susan G. Komen for the Cure in conjunction with the AACR Minorities in Cancer Research Council. The news conference was held twice, once in English and once in Spanish.
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In the study, Mexican Americans with such triple-negative breast cancer were diagnosed considerably younger than Latinas with other forms of the disease.
Others studies, though, suggest that less obvious cultural factors may have as much or even more influence than genetics on the poor prognosis of Mexican Americans with breast cancer. Some of the most compelling evidence of cultural risk comes from the Ella Binational Breast Cancer Study, still ongoing, of some 900 women in Mexico and another 325 Mexican-American women in border regions of Arizona and Texas.
An unusual finding is that only 22% of the Mexican-American participants discovered their breast cancer through a screening mammogram. That rate makes sense, though, considering that just 38% of Hispanic women age 40 and older get routine mammograms, according to data from the National Cancer Institute. The researchers said the suspicion is that the rate is even lower among Mexican Americans, who make up almost 60% of the Hispanic population in the US. Most Mexican Americans in the Ella study, 68%, discovered a breast tumor on their own.
When they discover a lump, Latinas often delay medical care. Forty-nine percent of the Ella study enrollees waited at least a month. Five percent waited a year or longer.
Their tumors are typically larger and more advanced than those diagnosed in white, non-Hispanics, Dr. Martinez noted. Mexican Americans also had more positive lymph nodes. The incidence of breast cancer is 40% lower in Latinas than in non-Hispanic whites. Yet Hispanics diagnosed with breast cancer are about 20% more likely to die of the disease than other women of similar age and stage.
“It's hard to tell whether their disease is worse because of their delayed care or biology,” Dr. Martinez said. “I suspect it's a combination of the two.”
Affordable Care Often Ignored
A closer look at the Ella data shows that the Latinas' behavior is more than a product of their ethnicity. The ones most likely to avoid mammography and delay cancer treatment typically are foreign-born, never finished high school, and speak very little English. Nearly a third of the Ella study participants who put off treatment cited a lack of health insurance and money as the reason.
“Hispanic women have three times the poverty of non-Hispanic whites,” said Amelie G. Ramirez, DrPH, MPH, Professor in the Department of Epidemiology and Biostatics and Director of the Institute for Health Promotion Research at the University of Texas Health Science Center at San Antonio, where she is also Director and the Dielmann Chair in Health Disparities Research and Community Outreach.
Although federal and private programs provide low-cost mammograms to indigent Mexican Americans, even a discounted $25 mammogram may seem like a needless expense to a woman struggling to feed her family.
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“They'd rather buy bread and milk for their children,” said Lorena Verdugo, a community health advisor with the El Rio Community Health Centers in Tucson.
Financial aid also is available for treatment, whether through Medicaid coverage or charity medical care. Yet to the many Mexicans here illegally, filling out aid applications raises fears that the information will lead immigration officials to their door.
“Even though the health system allows for clinicians to treat people regardless of their immigration status, there is a fear of being deported,” said Karen Patricia Williams, PhD, Assistant Professor of Reproductive Biology at Michigan State University.
Cultural Differences Foster Mistrust
Closely tied to the Mexican Americans' poverty and foreign culture is a mistrust of the health care system, a study of which she reported at the Disparities meeting. Nearly 60% of the Mexican-American women she surveyed said they believed that patients have been deceived by health care organizations.
“These are relatively low-income women,” she said. “They go to clinics and see different physicians all the time. You're not going to develop great rapport. There is mistrust in all these underserved communities. A lot of it has to do with how a [clinician] looks and whether they speak their language.”
Not surprisingly, the respondents in the study who had the highest levels of mistrust were the least likely to get mammograms regularly.
Without trusted clinicians to teach them about breast cancer screening and treatment, impoverished Latinas learn about the disease from the limited experience of family and friends.
“In the Hispanic community, if you have cancer, [the perception is that] it means death,” Dr. Ramirez said. “They don't get the message that with early detection, it can be treated.”
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Dr. Williams sees the same assumptions in the Hispanic migrant workers she's studied in Michigan. “There is definitely the concept of fatalism within the Latina community,” she said.
If Latinas do get the message on breast cancer, Dr. Ramirez and others believe, it will have to come from someone within their community.
“We do a good job of getting the word out to the general public,” Dr. Martinez said. “But maybe we're not using the right medium for Hispanics. We need to put faces on billboards that look like them. We need a more tailored approach.”
One of the most successful efforts has been the use of promotoras, Hispanic laywomen trained to teach Mexican Americans about breast health in their communities. The work is typically funded through grants from non-profits including the American Cancer Society and Susan G. Komen for the Cure. Promotoras succeed because they belong to the communities they serve.
“The biggest thing is to earn their trust,” said Ms. Verdugo, a promotora in Tucson. “It helps when you speak their language.
“We go out to home visits, one on one. Some women are shy. We offer transportation to their exams. They have no reason to say no. If they don't read or write, I fill out the forms for them.”
As educational efforts reach more Latinas, advocates expect fatalistic beliefs to shift toward optimism that breast cancer often can be cured.
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“Many Hispanic women do not see successful outcomes of family or friends diagnosed with breast cancer, so they end up equating a breast cancer diagnosis with death,” Dr. Ramirez said. “More community education is needed to promote a message of survival and hope.”
© 2009 Lippincott Williams & Wilkins, Inc.