P53 mutation linked to advanced CRC in African-Americans

Researchers have identified a possible genetic cause for an increased risk for a more advanced form of colorectal cancer in blacks that leads to shorter survival, according to data published in Clinical Cancer Research (15:2406-2416, 2009).

Upender Manne, PhD, and colleagues at the University of Alabama in Birmingham analyzed 137 colorectal adenocarcinomas from African-American patients and 236 colorectal adenocarcinomas from non-Hispanic whites. Researchers assessed these carcinomas for p53 mutations and genotyped for codon 72 polymorphisms.

Overall, whites and African-Americans had a similar rate of p53 mutations. However, the frequency of the Pro72 allele was higher in blacks (17%) compared with 7% among whites. By contrast, the Arg72 allele frequency was higher in whites (36%) than in African-Americans (19%).

Presence of the Pro72 allele in blacks was associated with a more than two-fold increase in mortality due to colorectal cancer (See “Minority groups protest CMS rejection of VC screening,” page 35).