A new study reported in JAMA suggests that compared with white individuals, black men and women have a higher
incidence and mortality from colorectal cancer and may develop cancer
at a younger age. Colorectal cancer screening might also be less effective
in black individuals, if there are racial differences in the
age-adjusted prevalence and location of cancer precursor lesions. Image via Wikipedia
The study also found that blacks are more likely than whites to have large colon
polyps, and their tumors tend to be located higher in the colon where
they are harder to detect.
are already known to have higher rates of colon cancer than whites and
up to 43 percent higher death rates from the disease, which kills
52,000 Americans annually. Since 1985,
colon cancer has risen among black men and is unchanged among black
women, while declining by as much as 25 percent among whites.
Early detection of colon cancer is considered key to successful treatment.
a study of approx. 5,500 blacks and 80,000 whites who had
colonoscopies, researchers at Portland VA Medical Center found nearly 8
percent of blacks had one or more polyps sized more than 9 millimeters
in diameter, compared to slightly more than 6 percent of whites.
tumours detected in blacks were more likely to be in the upper part of
the colon where a sigmoidoscopy would be unlikely to find it because the procedure that looks only at the
lower half of the colon. In addition, the
incidence of large polyps was noticeably high among black women younger
than 50, the age when adults are recommended to begin getting
Several factors may
account for the racial disparity in colon cancer rates, including
genetic differences that account for about a third of all cases of the
disease. However, blacks also have poorer access to health care and lower
rates of participation when screening is offered. These results, if repeated in other studies, strongly suggest that consideration should be given to initiation of screening before age 50 years in black women.