Outcomes Among African-Americans and Caucasians in Colon Cancer Adjuvant therapy Trials: Findings From the National Surgical Adjuvant Breast and Bowel Project

Reviewers: Li Liu, MD
Source: Journal of the National Cancer Institute, 91(22): 1933-1940, November 1999

Introduction

Some retrospective studies have reported poorer outcomes from colon cancer among African-Americans compared to Caucasian Americans. The cause of this disparity may be multifactorial, including diagnosis at later disease stage, unfavorable disease features, differences in treatment, and socioeconomic factors. Dignam and colleagues examined survival and related outcomes after treatment of primary colon cancer among African-American and Caucasian patients participating in randomized clinical trials of the National Surgical Adjuvant Breast and Bowel Project (NSABP).

Methods

The review was based on data from 5,969 white patients and 663 black patients enrolled in five NSABP clinical trials from 1977 through 1994.

Results

• Stage of disease was remarkably similar between two groups.
• The differences in disease-free survival between races were small and statistically insignificant; 70% and 68% for whites and blacks, respectively.
• The overall 5-year survival rate was significantly lower in blacks than in whites, 68% and 72% for blacks and whites, respectively.

Discussion

Survival rates in the general population who have colon cancer tend to be lower for African Americans than Caucasians. The difference is considerably less for African Americans and Caucasians entered in clinical trials. Higher mortality rates for chronic diseases other than cancer may contribute to the shorter overall survival times among African Americans.