Sylvester Comprehensive Cancer Center

UM Researchers Discover Moving to the U.S. Increases Cancer Risk for Hispanics

08.06.2009

A team of researchers at the University of Miami Miller School of Medicine has confirmed trends that different Hispanic population groups have higher incidence rates of certain cancers and worse cancer outcomes if they live in the United States than they do if they live in their homelands. Overall, the Miller School team found the cancer risk increases 40 percent or more for Hispanics in the United States.

“Hispanics are not all the same with regard to their cancer experience,” said lead study author Paulo S. Pinheiro, M.D., Ph.D., M.Sc., researcher in the Department of Epidemiology at the Miller School.

“Our study indicates targeted interventions for cancer prevention and control should take into account the specificity of each Hispanic subgroup: Cubans, Puerto Ricans or Mexicans,” added Pinheiro, who received support from the Portuguese Foundation for Science and Technology.

The study results are published in Cancer Epidemiology, Biomarkers & Prevention, a journal of the American Association for Cancer Research.

Pinheiro led a team of researchers that included Edward J. Trapido, Sc.D., professor of epidemiology and public health, Lora E. Fleming, M.D., Ph.D., M.P.H., M.Sc., professor of epidemiology and public health, Orlando Gomez-Marin, Ph.D., professor of epidemiology and public health, and David J. Lee, Ph.D., associate professor of epidemiology and public health. The group studied information collected by the Florida Cancer Data System, maintained at the Sylvester Comprehensive Cancer Center at UM. Recinda Sherman, M.P.H., senior research associate with FCDS, took part in the study, organizing data from more than 300,000 cancer cases among Florida residents diagnosed between 1999 and 2001.

Studies to date have classified all Hispanics as a single ethnic group, not considering the differences between population groups. This was the first study in the United States to analyze cancer risks for specific sub-groups: Cubans, Mexicans, Puerto Ricans, Central and South Americans. Pinheiro and colleagues evaluated the kinds of cancers occurring in each Hispanic population group and compared their risk after moving to the United States.

The results indicated that these population groups showed different patterns of cancer once they moved to the United States. Puerto Ricans had the highest cancer rates of all Hispanic subpopulations, while Mexicans had the lowest rates. Cubans’ risk of cancer most closely resembles that of non-Hispanic whites. In fact, the study found that Cubans and Puerto Ricans seemed to acquire higher risk for diet-related cancers, similar to the U.S. non-Hispanic white population, relatively quickly.

Cuban males had higher incidence of tobacco-related cancers; Puerto Rican men had high incidence of liver cancer; and Mexican women had a higher incidence of cervical cancer.

For all cancers combined, risk for most cancers was higher (at least 40 percent) among Hispanics living in the United States compared with those who live in their countries of origin. Colorectal cancer risk among Cubans and Mexicans who moved to the United States was more than double that in Cuba and Mexico. The same was said for lung cancer among Mexican and Puerto Rican women in Florida compared to those living in Mexico or Puerto Rico.

“This suggests that changes in their environment and lifestyles make them more prone to develop cancer,” Pinheiro said. “It is interesting that the groups which have an easier integration into mainstream American society, giving them access to health care, are also the groups with higher cancer rates even after accounting for the increased detection of certain cancers in this country.”

Trapido says the findings probably reflect an environmental effect, but it’s clear that Hispanic populations are both genetically and socioculturally different from each other. He adds that “studies such as this can lend clues to environmental differences between groups while holding genetic factors relatively constant within groups.”

Other researchers agree. “Hispanics are really heterogeneous from cultural and socioeconomic perspectives and represent several population groups,” said Amelie G. Ramirez, Dr.P.H., director of the Institute for Health Promotion Research, and co-associate director of the Cancer Prevention and Population Studies research program at the Cancer Therapy & Research Center at The University of Texas Health Science Center at San Antonio.

The Hispanic population in the United States is increasing and expected to triple by the year 2050, according to the U.S. Census Bureau. Ramirez, who was not involved in this research, said it is important to conduct studies like this to better understand these differences and learn what predisposes different population groups to certain types of cancer, in order to improve health outcomes.

These results present important opportunities for United States and international collaborations in the prevention, treatment and research of cancer. While physicians may not have to change the care they provide, Ramirez said they should be more aware of the diversity and differences in cancer prevalence among this population.

Patients should become better informed about some of the positive aspects of their original lifestyles and should be strongly discouraged from adopting unfavorable lifestyles that may be more common in the United States, such as unhealthy diets, smoking and alcohol use, according to Pinheiro and Ramirez.

Pinheiro and his team believe additional studies are warranted to assess the variations in cancer risk according to socio-economic status and length of time spent in the United States within each Hispanic population group. “The ideal next step,” said Pinheiro, “would be to evaluate habits that may predispose them to certain cancers.” In addition, more research should focus on these unique populations in relation to other diseases.

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