The Prognostic Significance of pSTAT1 and CD163 Expressions in Surgically Resected Stage 1 Pulmonary Squamous Cell Carcinomas.

Abstract

Tumor-associated macrophages (TAMs) play an important role in the initiation, progression, and metastasis of various solid tumors, and can polarize into M1 and M2 phenotypes. This study aimed to investigate whether TAM polarization is associated with clinical outcomes for early-stage pulmonary squamous cell carcinoma (SqCC). This retrospective study included 97 consecutive patients with stage 1 pulmonary SqCC. Immunohistochemical stains for M1 macrophage marker (pSTAT1) and M2 macrophage marker (CD163) were performed on paraffin-embedded tumors. The correlations of M1 and M2 macrophage expression, clinicopathologic characteristics, and clinical outcomes were analyzed. The 5-year disease-free survival (DFS) rate was 63.2%, and the 5-year overall survival (OS) rate was 74.8%. Positive pSTAT1 expression was noted in 42 patients (43.3%) and CD163 expression in 26 patients (26.8%). A statistically significant negative correlation between pSTAT1 and CD163 expression was found (p=0.015). Univariate analysis showed that extensive surgical resection, incomplete tumor excision, negative pSTAT1 expression, and positive CD163 expression were significantly correlated with both a poor DFS and a poor OS, whereas male gender was significantly correlated with a poor DFS only. Multivariate analysis showed that the pSTAT1/CD163 expression status was the only independent predictor for both DFS (p=0.023) and OS and (p=0.004). Markers identifying M1 and M2 macrophages, including pSTAT1 and CD163, can be used as prognostic indicators for patients with stage 1 pulmonary SqCC.