Abstract
BACKGROUND – Microsatellite instability is an important contributor to sporadic and familial colon cancer. Dysfunction of DNA mismatch-repair proteins by mutation or promoter methylation is a well-recognized cause of microsatellite instability. We conducted a study to identify variations in the prevalence of mismatch-repair protein deficiency in colon cancer and analyze clinical characteristics that may contribute to differences among ethnic subgroups of a community hospital-based patient population.
METHOD – A retrospective analysis of 272 cases was performed.
RESULTS – Reduced prevalence of mismatch-repair protein dysfunction was found in all non-Latino ethnicities (3.6%) compared to the Latino (13.1%) portion of our patient population (p=0.007). Mismatch repair protein deficient colon cancer was found to show significant correlation with right side location (p=0.017), young age in non-Latino ethnicities (p=0.030), tumor stage IIIC or greater (p=0.006), and high-grade histology (p=0.003). Colon cancer patients of Latino descent appear to have an increased rate of germline mutations within mismatch repair genes.
CONCLUSION – The prevalence of mismatch repair protein dysfunction in the non-Latino ethnicities of our patient population are less than reported in literature, while the rate of germline mutations within mismatch repair genes appears increased in those of Latino descent.