Expression and prognostic relevance of STAT3 and cyclin D1 in non-small cell lung cancer

Aim: To guide clinicians in selecting treatment options for patients with non-small cell lung cancer (NSCLC), it is desirable to have reliable markers predicting clinical outcome. This study analyzed the correlation between signal transducer and activator of transcription 3 (STAT3) and cyclin D1 in NSCLC and their association with clinicopathological features and survival. Methods: We investigated 65 specimens of NSCLC tissues by immunohistochemistry using STAT3 and cyclin D1 antibodies. First we determined the correlation between STAT3 and cyclin D1 expression and the clinicopathological features of the tumor. Then we assessed the prognostic relevance of STAT3 and cyclin D1. Results: A significant correlation was found between high levels of STAT3 expression and the degree of tumor differentiation. Additionally, a significant positive correlation was found between the expression of STAT3 and cyclin D1 (r=0.405, p=0.001). The overexpression of STAT3 and the presence of metastasis were significantly associated with shorter overall survival in univariate analysis (p=0.028 and p=0.036, respectively). Multivariate analysis confirmed that STAT3 expression was an independent prognostic factor (p=0.001). Conclusions: STAT3 might be correlated with tumor differentiation, and its elevated expression may be an adverse prognostic indicator for patients with NSCLC. Activation of the STAT3/cyclin D1 signaling pathway may be attributed to the malignant transformation of NSCLC and may represent a possible target for therapy.