Digging Into Data Shows Cancer’s Effects on Ethnic Groups

As the American population grows ever more diverse, cancer researchers are discovering that digging deep into demographic information can provide useful insight into the way cancer affects ethnic groups differently.

In recent months, studies published in Cancer Epidemiology, Biomarkers & Prevention, a journal of the American Association for Cancer Research, separately explored cancer trends in the Hispanic and Asian populations in the United States. The U.S. population of both groups has grown significantly in recent decades.

Paulo S. Pinheiro, MD, PhD

This month, a study led by Paulo S. Pinheiro, MD, PhD, an associate professor of epidemiology at the School of Community Health Sciences at the University of Nevada, Las Vegas, analyzed cancer mortality among various Hispanic ethnic groups in the state of Florida during the years 2008-2012. Pinheiro said his team chose to base their study on Florida data because it is the only state with statistically significant representation from all major Hispanic ethnic groups: Cuban, Puerto Rican, Mexican, Central American, Dominican, and South American.

Overall, Pinheiro said, the study showed that Hispanics had a 30 percent lower risk of dying of cancer than non-Hispanic whites. Hispanics had higher mortality rates from stomach and prostate cancers, but lower rates for lung, pancreas, and breast cancers, compared with non-Hispanic whites.

Analyzing the data by ethnic group, however, revealed some significant differences. For example, the Cuban population had the highest risk of dying of lung cancer. Pinheiro said this was unsurprising, since Cubans reported a high prevalence of smoking.

The study also showed that prostate cancer mortality among Dominicans was nearly double that of the non-Hispanic whites. Pinheiro said the disparity may reflect the fact that many Dominicans have African ancestry; prostate cancer incidence and mortality is higher in men of African descent.

Pinheiro said that the study findings suggest that some ethnic groups may benefit from recommendations that are specifically tailored to their risk factors. For example, he noted, a city with a large Dominican population could run advertising campaigns encouraging men to get screened for prostate cancer.

Pinheiro’s study on Hispanics echoed a study published in the same journal last September, which examined differences in how Asian ethnic groups experience cancer.

That study, led by Latha P. Palaniappan, MD, MS, a clinical professor of medicine at Stanford University School of Medicine in California, and Caroline A. Thompson, PhD, MPH, an assistant professor of epidemiology in the Graduate School of Public Health at San Diego State University, was based on data on cancer-related deaths of Asian Americans from 2003 to 2011 from the National Center for Health Statistics.

Latha Palaniappan, MD, MS

The study showed that while Asian Americans experience lower overall cancer mortality rates than non-Hispanic whites, there are certain exceptions that may be due to differences in biological or lifestyle risk factors.

For example, stomach cancer accounted for 10 to 15 percent of Korean cancer deaths, and 5 to 10 percent of Chinese, Japanese, and Vietnamese cancer deaths, compared with less than 2 percent of stomach cancer deaths in non-Hispanic whites. Liver cancer accounted for 22 percent of cancer deaths in Vietnamese males, 12 percent in Chinese males, and 10 percent in Vietnamese females, compared with less than 2.5 percent of liver cancer deaths in non-Hispanic whites.

The authors suggested that screening efforts tailored to specific populations could be useful in preventing cancer or diagnosing it at an earlier stage. For example, they noted, gastric cancer screening programs are well established in Japan and South Korea, and implementing such programs could potentially benefit the Japanese and South Korean populations living in America.

The authors of both studies said it’s worthwhile to look beyond broad ethnic labels and consider how a person’s nation of origin may affect his or her cancer risk.

Caroline A. Thompson, PhD, MPH

“Our findings suggest that national cancer prevention efforts may benefit from ethnic-specific information on the cancers that affect each specific subgroup within the Asian American population,” Thompson said.

“Hispanic populations are all different, reflecting their country of origin, cultural experiences, and socioeconomic status,” said Pinheiro. “If we can detect the differences among them, we can more easily identify public health strategies that could decrease their cancer risk and improve health outcomes.”