January 10, 2011

Geography Plays Role in Cancer Screening

(Ivanhoe Newswire) -- Not only do race and ethnicity play a part in whether a person gets screened for colon cancer or not, but where a person lives also plays a role, according to new research.

It is known that racial minorities have lower colorectal screening rates than whites. What hasn't been known, until now, is whether these differences also vary across geographic regions.

Thomas Semrad and colleagues at the UC Davis Cancer Center found that geography accounts for major differences in colorectal testing among non-whites but rarely vary for whites.

Semrad and his team analyzed data from 53,990 Medicare enrollees between ages 69 and 79 in eight states and 11 regions. Individuals were considered up-to-date on colon cancer screening if they had a colonoscopy or sigmoidoscopy within the prior five years or fecal occult blood testing within the past year. The researchers controlled for sociodemographic, medical and environmental factors that could affect regional differences in colorectal cancer screening.

Researchers found whites were more likely to be up-to-date on screening than other races everywhere, except in Hawaii, where Asian-Pacific Islanders had significantly higher screening rates than whites (52 percent versus 38 percent), possibly because of the influence of the Japanese in Hawaii -- who are known to have a high rate of gastrointestinal disorders.

"This is a stunning finding," Semrad was quoted as saying. "Screening rates among Asians in Hawaii were the highest of any group in any cancer registry area, including whites."

Geography also played a major role in screening rate variations among African Americans, Semrad found.

Researchers also found significant disparities when comparing white and Hispanic screening rates in all regions that had substantial Hispanic populations. However, there was basically no difference in screening rates among Hispanics in the different regions.

"The next step is to look at different geographic areas to see what are the determinants for minorities in terms of getting screened," Semrad said. "Are these culturally based? Are there problems with how health care systems are set up? What are the barriers? If we can figure this out, we would have a target to improve some of these disparities."

SOURCE: Cancer, published online January 10, 2010