Gene Variant Predicts Colon Cancer Mortality in Blacks
Proline variant associated with higher mortality based on race
THURSDAY, April 2 (HealthDay News) -- A variant of the p53 gene is associated with a higher risk of death in black patients with colorectal cancer compared with white patients, researchers report in the April 1 issue of Clinical Cancer Research.
Venkat R. Katkoori, Ph.D., from the University of Alabama at Birmingham, and colleagues compared the prognostic value of the codon 72 polymorphism of the p53 gene in colorectal adenocarcinomas from 137 blacks and 236 non-Hispanic whites.
The investigators found that the incidence of p53 mutations was similar in both groups. However, black patients had a higher frequency of the homozygous proline 72 allele (17 versus 7 percent) associated with an increased ability of cancer cells to proliferate, while white patients had a higher frequency of the homozygous arginine 72 allele (36 versus 19 percent) associated a greater potential to induce apoptosis. The researchers report that black patients that were homozygous for the proline variant had a higher incidence of missense p53 mutations and nodal metastasis, and a higher risk of death (hazard ratio, 2.15) than white patients (HR, 1.60).
"In this study, for the first time, we assessed the prognostic value of the codon 72 polymorphism of p53 in African American and Caucasian patients with colorectal cancers and showed that this polymorphism, specifically the Pro/Pro phenotype, is an independent factor of prognosis for African American patients," Katkoori and colleagues conclude.