Colon Cancer Gaps for Blacks, Whites Largely Due to Screening

WEDNESDAY, May 9 (HealthDay News) — Differences in screening account for much of the disparity in both colorectal (colon) cancer incidence and death rates between white and black Americans, a new study says.

The screening differences are responsible for 42 percent of the gap in cancer incidence and 19 percent of the disparity in death rates, according to the study.

The study also found that differences in survival linked to the stage of cancer at diagnosis (which likely reflect differences in treatment) account for an additional 36 percent of the disparity between blacks and whites in colorectal cancer death rates.

The results suggest that equal access to care could greatly reduce these disparities, according to the study published online April 18 in the journal Cancer Epidemiology, Biomarkers and Prevention.

Researchers led by Iris Lansdorp-Vogelaar, then a visiting scientist at the American Cancer Society, used a computer model to apply colorectal cancer screening and survival rates seen among whites to black Americans age 50 and older. They then compared those rates to actual incidence and death rates in blacks to determine how much of the racial disparities in colorectal cancer rates are due to differences in screening or stage-specific survival.

Applying to blacks the screening pattern seen among whites would reduce the gap in colorectal cancer incidence rates among those age 50 and older from about 28 to 16 cases per 100,000, and reduce the gap in death rates from nearly 27 to 22 deaths per 100,000, according to an American Cancer Society news release.

The researchers also found that if blacks had the same stage-specific relative survival as whites, the disparity in colorectal cancer death rates would decrease to about 17 deaths per 100,000.

Altogether, differences in screening and survival accounted for 54 percent of the disparity in colorectal cancer death rates between whites and blacks. The researchers said the remainder of the disparity most likely is due to lifestyle factors that increase the risk (such as alcohol use, smoking, obesity and meat consumption) and decrease the risk (such as physical activity and hormone-replacement therapy in women after menopause).

More information

The U.S. National Cancer Institute has more about colorectal cancer.