Objective: To investigate the expression of fragile histidine triad (FHIT) gene protein, FHIT and the possible relationship between FHIT expression and clinicopathological indices in colorectal carcinoma.
Methods: Detecting FHIT protein expression in 60 cases of formalin-fixed, paraffin-embedded colorectal carcinoma by citrate-microwave-SP immunohistochemical method, and analyzing its relationship to histological grade, Dukes' stage and 5-year survival rate.
Results: 55% of the carcinomas showed a marked loss or absence of FHIT expression compared with their matched normal mucosa. Carcinomas with reduced expression of FHIT correlated with their histological grade, Dukes' stage (P < 0.05) and 5-year survival rate. The distribution of decreased expression of FHIT was 7/16 in grade I carcinoma, 14/30 in grade II, 12/14 in grade III, respectively. The correlation between decreased expression of FHIT and Dukes' staging was 5/11 in stage A, 12/28 in stage B, and 16/21 in stage C. The difference between stage A, B with no lymph nodes metastases and the stage C with lymph nodes metastases was of significance (P < 0.05). The follow-up data of 39 cases showed that in the 5-year survival group, 13/25 were of the low FHIT expression carcinomas, while in 5-year deceased group 12/14 were of the low FHIT expression carcinomas (P < 0.05).
Conclusions: The reduced expression of FHIT may be associated with decreasing differentiation, metastasis and 5-year survival rate in colorectal carcinoma. It is suggested that decreased FHIT expression plays an important role in the development and progression of the tumor, and thus may become a new prognostic marker in colorectal carcinoma.