To explore S100A6 protein expression in lung adenocarcinoma and its clinical significance.

Immunohistochemisty (IHC) method was used to detect S100A6 protein expression in 98 cases of lung adenocarcinoma tissues and their paired adjacent normal lung tissues. The interrelation of S100A6 protein expression and clinical and pathological characteristics was analyzed by statistics methods.

The expression of S100A6 protein was higher in lung adenocarcinoma tissue than that in normal lung tissue (P<0.001). The expression of S100A6 protein was not related to age and sex(P>0.05), while is significantly related to smoking index, tumor differentiation, lymph node metastasis, distant metastasis and TNM stage(P<0.05). During the 5-year follow-up period, 77 patients of 98 patients died, 10 patients survived, 11 patients were lost, and the 5-year survival rate was 11.49%. The 5-year cumulative survival rate and the median survival time are respectively 63.6% and 68 months in the patients with low expression of S100A6 protein; 14.3% and 45 months in the patients with moderate expression of S100A6 protein and 0% and 29 months in the patients with high expression of S100A6 protein. Survival curve showed that the survival rate of patients with different S100A6 expression was statistically significant (P<0.05). Cox regression model revealed that the tumor differentiation, TNM stage and S100A6 protein expression were independent hazard factors of lung adenocarcinoma prognosis (P<0.05). The diagnostic sensitivity of the S100A6 protein expression level to lung adenocarcinoma was 84.69% and the specificity was 69.39%.

S100A6 protein is over-expressed in lung adenocarcinoma tissue and is closely related to the differentiation, stage, metastasis and prognosis of lung adenocarcinoma.