Gastrointestinal malignancies: when does race matter?

African Americans have a poorer survival from gastrointestinal cancers. We hypothesized that socioeconomic status may explain much of this disparity.

Four years of population-based Medicare and Medicaid administrative claims files were merged with the Michigan Tumor Registry. Data were identified for 18,260 patients with colorectal (n = 13,001), pancreatic (n = 2,427), gastric (n = 1,739), and esophageal (n = 1,093) cancer. Three outcomes were studied: the likelihood of late stage diagnosis, the likelihood of surgery after diagnosis, and survival. Bivariate analysis was used to compare stage and operation between African-American and Caucasian patients. Cox proportional hazard models were used to evaluate differences in survival. Statistical significance was defined as p < 0.05.

In unadjusted analyses, relative to Caucasian patients, African-American patients with colorectal and esophageal cancer were more likely to present with metastatic disease, were less likely to have surgery, and were less likely to survive during the study period (p < 0.05). In a multivariate analysis, African-American patients had a higher likelihood of death from colorectal cancer than Caucasian patients. This difference, however, did not persist when late stage and surgery were taken into account (hazard ratio = 1.15, 95% CI = 1.06 to 1.24). No racial differences in survival were observed among patients with esophagus, gastric, or pancreatic cancer.

These data suggest that improvements in screening and rates of operation may reduce differences in colorectal cancer outcomes between African-American and Caucasian patients. But race has little influence on survival of patients with pancreatic, esophageal, or gastric cancer.