Study reveals cancer diagnosis more deadly in blacks
A study on deaths among African Americans diagnosed with cancer gives a grim picture of survival, according to researchers at the University of South Carolina’s Arnold School of Public Health.
One of the nation’s first studies to track the ratio of deaths based on the incidence of specific cancers, the report in the June issue of the journal Cancer yields a powerful measure of the scope of the cancer problem among men and women, whites and blacks.
Researchers examined the eight public-health regions in South Carolina for the number of cancers and cancer deaths from 2001 - 05 and then compared these numbers to corresponding national rates.
Although the study was done in South Carolina, it could be replicated in other states or regions by using cancer incidence and death data, said Dr. James Hebert, the study’s lead author and a professor in the Arnold School.
Comparing and mapping race- and sex-specific cancer “mortality-to-incidence ratios” (MIR) provide a powerful method to observe the scope of the cancer problem, he said.
“We already knew that South Carolina is a dramatic example of health disparities,” said Hebert, director of the Statewide Cancer Prevention and Control Program in South Carolina. “This study is alarming. It shows health disparities in a visual, graphic way in geographic spaces.”
African Americans had much higher mortality rates than whites even when a specific cancer had a lower incidence rate, Hebert said.
For example, S.C. data reveal that African Americans smoke less than whites. But statistics on oral cancer show that African Americans have a higher MIR in seven of the state’s regions.
“Comparing this data to national MIR rates shows the severity of the problem,” said Hebert.
Other study findings:
- Racial differences: The largest racial differences are for prostate, oral and female breast cancers. African Americans had MIRs nearly twice those of whites.
- Female breast cancer: The MIR for breast cancer among white females is at the national average or below for all but one region – the Pee Dee – of South Carolina. Among African-American females, the MIR is at least 20 percent higher than the national average in four regions and more than 20 percent higher in the state’s remaining four regions.
- Colorectal cancer: Colorectal cancer MIRs for white men and women is at the national average or below. But for African Americans living in the Pee Dee and the counties along the Grand Strand and Lowcountry, the MIR is above the national average by at least 20 percent.
- Oral cancer: Among whites, only one region of the state is more than 20 percent higher than the national average for oral cancer. This region includes Aiken, Barnwell, Calhoun, Orangeburg, Bamberg and Allendale counties. However, the oral cancer MIR for African Americans is greater than 20 percent of the national average in all but four counties: Hampton, Colleton, Jasper and Beaufort. These four counties are about 10 percent higher than the national average.
- Prostate cancer: In 43 of the state’s 46 counties, the MIR for lung cancer among African Americans is more than 20 percent of the national average. The remaining three counties – Williamsburg, Georgetown and Horry counties – are 10 to 20 percent higher than the national average.
- Lung cancer: The MIR for lung cancer among whites was at the national average for the three regions along the coast of South Carolina and up to 10 percent higher for the remaining five regions. Among African Americans, however, only three counties in the Palmetto State – Charleston, Berkeley and Dorchester counties – were at the national average. The remaining 43 counties were above the national average.
Hebert said the study does not explain the cause of the racial and sex differences among the cancer rates.
“It may be that African Americans are getting a particularly virulent type of cancer,” he said. “They may be diagnosed at later stages or not getting follow-up care after a cancer diagnosis. We don’t have those answers.
“But this study does give public-health and other healthcare professionals a better understanding of the areas of the state with the greatest cancer incidences and deaths. It shows where we need to target our resources.”
Visit http://cpcp.sph.sc.edu/, and go the link, “CPCP article,” to read more about the study.