Clinical and prognostic significance of signal transducer and activator of transcription 3 and mucin 1 in patients with non-small cell lung cancer following surgery

Signal transducer and activator of transcription 3 (STAT3) and mucin 1 (MUC1) are associated with development, progression and a poor prognosis in several types of cancer. The present study investigated the levels of STAT3 and MUC1 in patients with non-small cell lung cancer (NSCLC) following surgery. In total, 98 patients with NSCLC were enrolled into the study. STAT3, phosphorylated (p)-STAT3 and MUC1 expression in NSCLC specimens obtained from patients were investigated using immunohistochemical analysis. Enumeration results were analyzed using the χ(2) test or Fisher's exact probability test. Spearman's rank correlation was used to analyze correlations between STAT3, p-STAT3 and MUC1 expression. Univariate analysis was conducted using the Kaplan-Meier estimator curve method and Cox regression multivariate analysis was performed in order to determine prognostic factors. Results demonstrated that STAT3 and p-STAT3 expression was identified in 82 and 51 patients, respectively. Furthermore, the expression of MUC1 was identified in 61/98 cases (62.2%) and STAT3 expression was significantly associated with pathological tumor-node-metastasis stage (pTNM; P<0.01). p-STAT3 expression was associated with pathological type (P<0.01), pathological lymph nodes (pN; P<0.01) and pTNM (P<0.05). MUC1 expression was associated with pathological type (P<0.05), pathological tumor pT (P<0.05), pN (P<0.01) and pTNM (P<0.01). STAT3 expression was positively associated with p-STAT3 expression (P<0.05) and p-STAT3 expression was positively associated with MUC1 expression (P<0.01). Overall, the results identified that the 3-year survival rate was 56.1% and was significantly associated with the degree of differentiation (P<0.05), pT (P<0.01), pN (P<0.01), pTNM stage (P<0.01), p-STAT3 expression (P<0.01) and MUC1 expression (P<0.05). Results obtained from the Cox multivariate regression analysis demonstrated that pN and p-STAT3 expression were independent factors associated with the 3-year survival rate.