[Expression of major histocompatibility complex class I chain-related protein A and B in operable lung adenocarcinoma and its clinical significance].

OBJECTIVE:To explore the expression of major histocompatibility complex classⅠchain-related protein A and B (MICA/B) in operable lung adenocarcinoma and its clinical significance. METHODS:Between January 2002 and December 2003, 100 patients with operable lung adenocarcinoma in People's Hospital of Zhengzhou were collected. The expression of MICA/B was examined by immunohistochemistry staining.According to immunohistochemical staining, the cases with score ≥5 points were high expression of MICA/B while <5 points were low expression of MICA/B.Chi-square test was utilized to analyze the relationship between MICA/B expression and clinicopathologic features. The association between MICA/B protein and overall survival in the patients with operable lung adenocarcinoma was analyzed by Kaplan-Meier survival curve, together with Log-Rank test. The COX regression model was established to analyze the single and combined effects of these covariants. RESULTS:The percentage with high expression of MICA/B protein in operable lung adenocarcinoma tissue was 38% (38/100). The over-expression rate of MICA/B protein in the group with mutant epidermal growth factor receptor (EGFR) gene was significantly higher than that in the group with wild EGFR gene (93.8% vs 11.8%, P<0.001). No statistical significance was observed between the expression of MICA/B protein and other clinicopathologic parameters, including age, sex, TNM stage, T- staging, histological grade and lymph node metastasis. Kaplan-Meier analysis showed that overexpression of MICA/B protein was closely associated with shorter survival time (10.4 vs 28.9 months, P=0.005). CONCLUSION:Overexpression of MICA/B in operable lung adenocarcinoma tissue is closely related to the mutations of EGFR and overall survival, which may be a poor prognosis indicator in patients with operable lung adenocarcinoma.