Lower socioeconomic status decreases chances of early detection and survival of colorectal cancer

An abstract presented at the American Association for Cancer Research's Seventh Annual International Conference on Frontiers in Cancer Prevention Research shows that lower socioeconomic status reduced the chance of early stage diagnosis and survival of colorectal cancer in Colorado.

"Diagnosis of colorectal cancer at an early stage can lead to better survival. Good screening tests for early stage diagnosis of colorectal cancer are available," Alma Palisoc, M.D., a preventive medicine resident physician at the University of Colorado Denver and lead author of the study, said. "However, those in the lower socioeconomic groups and those having no health insurance or only Medicaid coverage are more likely to be diagnosed with colorectal cancer at a later stage of disease when survival is worse."

In the study, Palisoc, and her co-authors from the Colorado School of Public Health and the Colorado Department of Public Health and Environment, used data from 21,212 colorectal cancers reported to the Colorado Central Cancer Registry over a 12-year period. Using information from the 2000 U.S. census on block group socioeconomic characteristics, they then examined differences in early-stage diagnosis and five-year, cause-specific survival by socioeconomic status.

They found early-stage diagnosis was less common for all three socioeconomic groups among those with no health insurance or only Medicaid coverage. They also observed that early-stage diagnosis was less common among those younger than 65 among lower socioeconomic groups. "In contrast, for those 65 and older, Medicare covers colorectal cancer screening tests and so earlier-stage diagnosis was observed to be similar among the three groups." More important, for those under the age of 65, there was a 19 percent decrease in five-year survival between the higher and lower groups.

"We concluded that both lack of health insurance and being in a lower socioeconomic strata are important risk factors for later stage colorectal cancers and for poorer survival from colorectal cancer," Palisoc said.

Colorectal cancer incidence rates have declined considerably over the last two decades, due to increased screening, which allows physicians to detect and remove colorectal polyps before forming cancer. "Later detection and, therefore, lower survival of colorectal cancer among those in the low socioeconomic strata were most likely due to barriers in accessing screening tests," Palisoc said.

"These findings can hopefully raise more awareness to the importance of removing barriers to lifesaving health services such as screening tests and treatment for colorectal cancer, " Palisoc said. "We need to identify ways to provide such services in Colorado and across the nation, even for people without health insurance."