The clinicopathological characteristics and prognosis of mucin-laden nonmucinous lung adenocarcinoma.

Abstract

The study objective was to investigate the clinicopathological characteristics and prognosis of mucin-laden nonmucinous lung adenocarcinoma. Between October 2017 and December 2019, a total of 529 patients with nonmucinous lung adenocarcinoma who received surgical resection were retrospectively collected. Disease-free survival and overall survival were estimated by the Kaplan-Meier method and compared using the log-rank test. Adjusted hazard ratio (aHR) with 95% CI of the prognosticator was calculated by Cox proportional hazards model, and cumulative incidence function was measured by competing risk regression model. In the entire cohort, nearly all patients were diagnosed as intermediate (n = 301, 56.9%) or high grade (n = 225, 42.5%) according to the International Association for the Study of Lung Cancer pathologic grade system, and the most frequent mucin-distribution pattern was extracellular distribution (n = 307, 59.5%), followed by both intracytoplasmic and extracellular distribution (22.3%) and intracytoplasmic distribution (18.2%). Among different mucin-distribution patterns, tumors with extracellular mucin were associated with the most prevalent tumor of 2 to 5 cm (59.7%) and EGFR mutation (47.8%), and tumors with intracytoplasmic and extracellular mucin were associated with EML4-ALK rearrangement (37.5%). Tumors with extracellular mucin had poorer disease-free survival (aHR, 1.871, 95% CI, 1.158-3.020) and overall survival (aHR, 4.243, 95% CI, 1.618-11.125) compared with tumors with intracytoplasmic mucin. Subsequently, analysis of the recurrent pattern using competing risk regression model revealed that tumors with extracellular mucin were a predictor for distant recurrence (aHR, 2.824, 95% CI, 1.607-4.960). This study provided a comprehensive description of the clinicopathological characteristics and prognosis of patients with nonmucinous lung adenocarcinoma and demonstrated that mucin-distribution patterns significantly impact prognosis.