Moving to U.S. increases cancer risk for Hispanics

Aug 6 2009

Results of a new study confirm 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.

"Hispanics are not all the same with regard to their cancer experience," said Paulo S. Pinheiro, M.D., Ph.D., M.Sc., researcher in the Department of Epidemiology at the University of Miami Miller School of Medicine.

"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 is the study's lead researcher. Pinheiro received support from the Portuguese Foundation for Science and Technology.

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

Studies to date have classified all Hispanics under the same umbrella, as a single ethnic group, hiding the differences between each population group.

"They 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 according to Ramirez - nearly one in every three people will be Hispanic by 2050. 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.

Pinheiro and colleagues evaluated the kinds of cancers occurring in each Hispanic population group and compared their risk after moving to the United States. They conducted the study in Florida, which has a diverse Hispanic community composed of Cubans, Mexicans, Puerto Ricans, Central and South Americans.

The results indicated that these population groups showed different patterns of cancer once they moved to the United States; Mexicans had the lowest rates of cancer overall and Puerto Ricans had the highest rates of cancer. Cubans' risk of cancer most closely resembles that of non-Hispanic whites. Similar to the U.S. non-Hispanic white population, Cubans and Puerto Ricans seemed to acquire higher risk for diet-related cancers relatively quickly.

Furthermore, 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 Floridian women compared to those 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 puzzling that the groups for which integration in mainstream American society is easier, including access to health care, are also those with higher cancer rates even after accounting for the increased detection of certain cancers in the United States."

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.

"Don't assume that all Hispanics are the same," Ramirez said. "Physicians should probe Hispanic patients more on their background and family history to identify any problematic behaviors that could contribute to health problems."

Patients should become better informed of 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.

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, in order to evaluate habits that may predispose them to certain cancers. More research should focus on these unique populations in relation not only to cancer, but to other diseases, according to the researchers.