MUC1 associates with smoking, prognosis and histological subtypes in lung adenocarcinoma

The depolarized expression of Mucin-1 (MUC1) is a marker of poor prognosis in lung cancer. MUC1 binds with the epithelial growth factor receptor 1 (EGFR), which is considered as a predictive marker in lung cancer, whereas the prognostic significance of Mucin-4 (MUC4) in lung cancer is unclear. We aimed to study the immunohistochemical expression of MUC1 and MUC4 and their receptors EGFR and epithelial growth factor 2 (Her2) in surgical specimens of 106 Finnish lung adenocarcinoma patients. The results of the analyses were correlated with clinical parameters and histological adenocarcinoma subtypes. The expression of the depolarized MUC1 correlated with the histological subtypes. 82.6% of the solid-predominant adenocarcinomas, 77.8% of the acinar-predominant adenocarcinomas, and 75.0% of the cribriform variants of the acinar-predominant adenocarcinoma expressed depolarized MUC1 (p< 0.001). An inverse correlation was observed between the extent of the lepidic growth pattern and depolarized MUC1 expression (p< 0.001). Depolarized MUC1 showed a trend towards a shorter survival in the level of the entire study population and also in the patients with the acinar-predominant subtype, correlating also with the tumor stage (p= 0.002). Depolarized MUC1 expression associated with the smoking history (p< 0.001) but not with COPD. No relevant histologic or clinical correlations were found for the expression of MUC4, EGFR, or Her2. We conclude that the immunohistochemical expression of MUC1, but not MUC4 or EGFR, associated with several clinical and histological parameters in lung adenocarcinoma including smoking, shorter survival, higher stage as well as the solid- and acinar-predominant subtypes.