Colon cancer survival varies by race and ethnicity

NEW YORK (Reuters Health) - Survival rates for people with colorectal cancer are different in various racial and ethnic groups, with blacks faring worse than other groups, according to a report by US researchers.

Decreased colorectal cancer survival in blacks compared with whites is well documented, the authors explain, but few studies have investigated colorectal cancer survival in other racial or ethnic groups.

Dr. Scarlett Lin Gomez from the Northern California Cancer Center, Fremont, and associates used linked databases to investigate factors associated with racial and ethnic survival patterns. Their findings appear in the online journal BMC Cancer.

Blacks, Hispanics, and Filipinos were more likely than other groups to be diagnosed with stage III or IV (i.e., advanced) disease, the authors report.

Blacks and Japanese were less likely than Hispanics and Chinese to receive guideline treatment for stage III colon cancer, and relatively fewer blacks, Japanese, and Filipinos received treatment according to guidelines for stages II and III rectal cancer.

Mortality rates due specifically to colorectal cancer were 33 percent higher among blacks and 16 percent higher among Hispanic males than among whites, the researchers report, while mortality rates were lower among Japanese and comparable among Hispanic females, Chinese, and Filipinos.

Even after adjustment for disease characteristics, education level, poverty, and income, blacks still had mortality 16 percent higher than among whites. Conversely, mortality among Hispanic males was no longer higher after adjustment for these factors.

"We found evidence that ... racial/ethnic disparities in colorectal cancer survival may be reduced by increasing access to screening," the investigators write. "However, among blacks, survival disparities compared to whites and other racial/ethnic groups persist even after accounting for a comprehensive set of sociodemographic, clinical, and treatment characteristics."

Additional research "is necessary to identify the factors and mechanisms leading to the poorer outcomes among US blacks," the authors conclude.

SOURCE: BMC Cancer, October 16, 2007.