PROGNOSTIC VALUE OF hMLH1 AND hMSH2 IMMUNOHISTOCHEMICAL EXPRESSION IN NON-SMALL CELL LUNG CANCER. A TISSUE MICROARRAY STUDY

Key words: Non-small cell lung cancer/Prognosis/Mismatch repair/hMLH1 / hMSH2/Tissue microarray Background: hMLH1 and hMSH2 genes are both known to play a role in DNA mismatch repair. Nonetheless, the clinical significance of hMLH1 and hMSH2 protein expression in lung cancers remains unclear. Aim: The aim of this study was to investigate the immunohistochemical expression of hMLH1 and hMSH2 proteins in tumor specimens from 179 non–small cell lung cancer (NSCLC) patients using a tissue microarray technique and to correlate these results with other clinicopathological variables, including the disease specific and overall survivals. Method: hMLH1 and hMSH2 protein expression was evaluated by immunohistochemistry using monoclonal antibodies G168-728 for hMLH1 and FE11 for hMSH2 protein expression analysis. The Pearson χ2 test was used to compare the hMLH1 and hMSH2 alterations among the cases and between various clinical and laboratory variables. P < or = 0.05 was considered statistically significant. Results: Alteration of hMLH1 and hMSH2 protein expression was observed in 10 % of patients. No significant cor-relation was found between the protein expression and patient age, smoking status, tumor histology or disease stage and disease free and overall survival. Conclusions: Alterations in the expression of hMLH1 and hMSH2 proteins did not have any prognostic value in stage III. NSCLC patients