Study: California ethnic groups seeing increased cancer rates

Black Issues in Higher Education, Jan 13, 2005

LOS ANGELES

A statewide study on cancer and ethnicity hints that cancer rates among immigrant groups may be tied to their degree of assimilation into American culture. The study, released by the University of Southern California's Norris Comprehensive Cancer Center, marks the first statewide look at cancer rates among Vietnamese and South Asians and provides a roadmap for what the nation's cancer landscape could look like in 20 years, researchers say.

"We're all in the same community here, drinking the same water and breathing the same air, and yet these cancer rates and trends are profoundly different by ethnic group," says Dr. Dennis Deapen, director of the Los Angeles Cancer Surveillance Program and co-editor of the study. "The best explanation is that California is an immigration landing spot."

Cancer rates vary considerably among California's ethnic groups, with Blacks and Whites reporting the highest overall rates and Asians, particularly South Asians, reporting the overall lowest. California, with 34.5 million people, makes up 12 percent of the nation's population.

These findings are from the report "Cancer Incidence and Mortality in California: Trends by Race and Ethnicity 1988-2001." The study includes 14 years of data from nearly two million Californians diagnosed with invasive cancer, and in some cases, noninvasive cancer.

The study indicates that ethnic groups that have been in the country the longest--Blacks and Whites--have the highest overall rates of cancer, while recent immigrants such as Vietnamese, Koreans, Indians, Pakistanis and Bangladeshis have lower overall rates. Hispanics fall somewhere in the middle.

Among men, Blacks ranked No. 1 for overall cancer risk. They are nearly three times more likely to get cancer than their South Asian counterparts and five times more likely to die from it, according to the study. Whites ranked second in overall cancer rates among males. Among females, White women ranked No. 1, with Black women in second place.

Some researchers believe the study shows that as immigrants assimilate--and eat more high-fat, low-fiber food and exercise less--their cancer risk increases. One example of this is breast cancer rates in Japanese American women, which used to be extremely low, says Deapen.

"The Japanese have now skyrocketed to as high as the very highest rates of breast cancer, which is among White women in Los Angeles," Deapen says. "The reason for that is they're the first, the earliest, wave in Asian immigration and Filipinos are fight behind them."

Deapen believes Chinese and Koreans--later Asian immigrants to California--will soon report similar increases in breast cancer.

Conversely, in some cases, immigrants who hold onto their native culture longer report higher rates of certain types of cancer, the study suggests.

Asians had the highest incidence of stomach cancer, with Koreans experiencing a one and a half-fold increase over Japanese and Vietnamese between 1993 and 2001. Stomach cancer has been blamed, in part, on a bacterium found in Asian countries that could be present in food, says Dr. Myles Cockburn, the study's co-editor.

The report is available online at <www.ccrcal.org>.

--Associated Press