Blacks with colon cancer are about half as likely as whites to get a type of colon cancer that has a better chance of survival, a new study says.
This may be one of the reasons why blacks are more likely to die of colon cancer than whites, the researchers said.
Researchers analyzed information from 503 patients in the North Carolina Colon Cancer Study. They found that 7 percent of blacks and 14 percent of whites had cancer with a genetic marker called microsatellite instability (MSI).
MSI colon cancer is known to be resistant to a chemotherapy drug. However, even without chemotherapy, patients with MSI colon cancer tend to have better outcomes than those without the genetic marker.
“We know that patients with MSI colon cancer do better without chemotherapy. But these improved survival benefits are limited among African-Americans with colon cancer,” study author Dr. John Carethers, chair of internal medicine at the University of Michigan Medical School, said in a university news release.
The researchers also found that black patients were more likely than whites to have cancer on the right side of the colon. Compared to left-sided colon cancer, right-sided cancer is more likely to be missed during screening and more likely to more advanced when it’s found.
“Right-sided colon cancer may be the ‘black ice’ of the colon, unseen but potentially deadly. Strategies to better recognize and detect right-sided cancer may need to be pursued in a broader fashion,” Carethers said.
The study was published June 23 in the journal PLoS One.