Racial disparities

Although it is well documented that blacks have higher rates for colorectal cancer incidence and mortality, the reasons are not clear. Some very sound and rationale researchers have stated that the disparity in incidence and mortality are likely biologic. However, this would seem to fly in the face of what I have been taught in my population health classes about racial disparities in general, which is that they are almost exclusively non-biologic — maybe they are socioeconomic, maybe health care utilization, maybe cultural — but not biologic.

Although I have been open to the concept that it may be a real biologic phenomenon, I can't say that I have been overwhelmed with the evidence to this end. A recent study based off the large prospective Prostate, Lung, Colorectal, Ovarian study published in the Journal of the National Cancer Institute this week supports that the racial disparity is in fact health care utilization related, at least for early stage tumors.

In addition to finding that blacks were less likely to get a colonoscopy after a positive flexible sigmoidoscopy (62% vs. 72%), the researchers also found that blacks were more likely to have right sided lesions, that would not classically be detected via flexible sigmoidoscopy. And it appears that the disparity found in the study is not just health care access related, as the effect was modulated by education, such that the lower the educational attainment, the lower the likelihood of getting the full colon examined.