Clinical and pathological implications of the presence of MECA-79-expressing tumor cells in pathological stage IA lung adenocarcinoma

Approximately 15 % of patients with resected pathogenic stage IA lung adenocarcinoma develop recurrent disease, indicating the formation of a cancer metastasis-promoting microenvironment. MECA-79 epitope is a glycan structure modulating immune response, normally expressed on high endothelial venules. Recently, ectopic MECA-79 expression has been discovered in several cancer cells and was associated with poor prognosis. In this retrospective cohort study, we aimed to investigate the clinical and pathological significance of tumoral MECA-79 expression in early-stage lung cancer. Using MECA-79 antibody to identify MECA-79+ tumor cells, we analyzed 195 patients with pathological stage IA lung adenocarcinoma undergoing lobectomy, assessing clinical, radiological, and pathological factors. We applied the Kaplan-Meier analysis to evaluate overall and recurrence-free survival as well as univariate and multivariate logistic regression to identify risk factors of postoperative recurrence within 5 years. Statistical significance was set at P < 0.05. Among 195 patients undergoing lobectomy, immunohistochemical analysis revealed tumoral MECA-79 expression in 5.1 % of cases (n = 10). Patients with MECA-79+ tumor cells exhibited a larger pathological invasive size (2.1 vs. 1.6 cm, P = 0.044), along with higher vascular invasion rates (90.0 % vs. 40.0 %, P = 0.0023) and 5-year postoperative recurrence (40.0 % vs. 7.6 %, P = 0.0061). Kaplan-Meier analysis demonstrated significantly worse recurrence-free survival for patients with MECA-79+ tumor cells (5-year rate: 54.9 % vs. 87.4 %, P = 0.003). Multivariate logistic regression identified presence of MECA-79+ tumor cells as an independent predictor of 5-year postoperative recurrence (odds ratio, 6.51; P = 0.025). Our results indicated that tumoral MECA-79 expression is associated with recurrence of resected pathological stage IA lung adenocarcinoma, warranting validation in multicenter cohorts.