Studies of colorectal adenocarcinoma (CRC) indicate a higher mortality rate for African Americans compared with Caucasians in the United States. In the current study, the authors evaluated the racial differences in survival based on tumor location and pathologic stage between African-American patients and Caucasian patients who underwent surgery alone for CRC.
All 199 African American patients and 292 randomly selected, non-Hispanic Caucasian patients who underwent surgery between 1981 and 1993 for first primary sporadic CRC at the University of Alabama–Birmingham (Birmingham, AL) or an affiliated Veterans Affairs hospital were assessed for differences in survival. None of these patients received preoperative or postoperative neoadjuvant or adjuvant therapy. Survival curves were generated using the Kaplan–Meier method, and hazard ratios with 95% confidence intervals (95% CI) were estimated from Cox proportional hazards models, adjusting for demographic and tumor characteristics.
African Americans were 1.67 (95% CI, 1.21–2.33) and 1.52 (95% CI, 1.12–2.07) times more likely to die of colonic adenocarcinoma (CAC) within 5 years and 10 years of surgery, respectively, compared with Caucasians. Racial differences in survival were observed among patients with Stage II, III, and IV CAC; however, the strongest and statistically significant association was observed among patients with Stage II CAC. There were no significant racial differences in survival in patients with rectal adenocarcinomas.
The current findings suggest that the decreased overall survival at 5 years and 10 years postsurgery observed in African-American patients with CAC may not be attributable to tumor stage at diagnosis or treatment but may be due to differences in other biologic or genetic characteristics between African-American patients and Caucasian patients. Cancer 2004. © 2004 American Cancer Society