Napsin A is an independent prognostic factor in surgically resected adenocarcinoma of the lung.

INTRODUCTION: Napsin A is regarded as a marker of lung adenocarcinoma. However, no comprehensive analyses of napsin A-positive lung ADCs or the prognostic significance of napsin A expression have been reported to date. METHODS: 110 primary lung adenocarcinoma cases were analyzed for clinicopathologic parameters, including overall survival, stage, histology, napsin A and TTF-1 expression, EGFR mutation, and ALK rearrangement. RESULTS: Napsin A-positive adenocarcinomas were significantly more prevalent among tumors characterized as relatively small (p = 0.023), non-solid predominant (p < 0.001), non-mucinous/enteric (p < 0.001), positive for TTF-1 expression (p < 0.001), and positive for EGFR mutation (p = 0.001). Multivariate analysis of overall survival demonstrated that the absence of napsin A was an independent prognostic factor for reduced survival time (p = 0.002). CONCLUSION: Clinicopathologic characteristics associated with napsin A-positive lung ADC are similar to and overlap with those of TTF-1-positive ADCs. The absence of napsin A is an independent poor prognostic factor in surgically resected adenocarcinoma. Further studies are necessary to determine the role of napsin A in the progression of lung adenocarcinoma.ope