Clinicopathological Significance of BAT26Instability in 184 Patients with Colorectal Cancer

ABSTRACT

Microsatellite instability (MSI) occurs in 90% ofcolorectal cancer (CRC) from HNPCC patients and 15%of sporadic CRC. Patients with CRC and MSI have adistinct phenotype. OBJECTIVE: this study evaluates theisolated clinicopathological significance of BAT26instability by itself in patients with CRC. METHODS:From 1995 to 2000, 184 patients submitted to CRC surgerywere selected at random. Medical records were studiedin order to determine clinical data and BAT26 analysiswas carried out. RESULTS: BAT26 instability was foundin 22 (12%) of the 184 cases and was correlated to proximalcolon tumors (p<0.001); CRC from HNPCC patients(p=0.002); poor cell differentiation (p=0,025); andmucinous component (p=0,007). BAT26 instabilitytumors have shown a slight trend toward absence ofmetastases (p=0,082). The five-year cancer-specificsurvival was 65% and 85% for stable and instable BAT26,respectively, with no statistical significance.CONCLUSION: BAT26 instability should be considereda useful screening method to select CRC patients forMSI.