July 7, 2011 -- Colorectal cancer screening is reducing the number of deaths from the disease, but death rates vary widely among regions and states, according to a new report.
Colorectal cancer death rates are higher in Southern states along the Appalachian Mountain corridor and lower in the Northeast, researchers say.
Their report is published in Cancer Epidemiology, Biomarkers & Prevention. It comes just days after the CDC reported that deaths from colorectal cancer have declined dramatically in recent years due to greater emphasis on screening procedures.
But the new report indicates that though the death rate is decreasing across the country, it is dropping unevenly.
American Cancer Society researchers examined death data from 1990 to 2007 across the U.S. and found that reductions in death rates between 1990-1994 and 2003-2007 ranged from no decrease in Mississippi to 9% in Alabama to more than 33% in Massachusetts, Rhode Island, New York, and Alaska.
The researchers say there is a strong correlation between higher rates of screening for colon cancer and bigger reductions in death rates from the disease.
The researchers note that screening rates are lower among people who are poor and uninsured. In Mississippi, 18.8% of people had no health insurance in 2007. But in Massachusetts, only 5.4% lacked health insurance coverage.
Ahmedin Jemal, DVM, PhD, vice president for research of the American Cancer Society, says the differences in death rate reductions by state "are huge."
Overall, states in the South had a lower reduction in death rates than states in the North, the researchers say, and cite economic differences as a main reason.
More than 20% of people in Mississippi were living below the poverty line in 2007, compared with a national average of 13%.
"It used to be that the highest rates of colorectal cancer mortality were in the northeastern part of the United States, but now we've really seen a switch," Elizabeth Jacobs, PhD, of the University of Arizona, says in the news release. "It shows the importance of access to screening."
Colon Cancer in Southern States
The researchers say that in general screening is lower and the proportion of late-stage colorectal cases higher in Southern states, compared with other regions. Southern states have a greater proportion of poor people and people without health insurance.
Other possible factors include less access to health care facilities and treatment.
Also, obesity is much higher in Southern states, and progress in reducing smoking rates has been slower. Both are risk factors for colorectal and other cancers.
"The relatively higher proportion of blacks in Southern states is another factor that may have contributed to the less favorable trend in reducing [colorectal cancer] mortality for all races combined in this region," the authors write.
Nationally, colorectal cancer death rates have declined much more slowly among African-Americans.