Peritumoral Lymphatic Vessels Associated with Resistance to Neoadjuvant Chemotherapy and Unfavorable Survival in Esophageal Cancer.

Abstract

BACKGROUND: Peri- or intra-tumor lymphangiogenesis is induced in several types of cancer. However, the significance of peritumoral lymphatic vessels (LVs) in esophageal cancer (EC) remains to be clarified. METHODS: This study included 162 eligible EC patients with or without neoadjuvant chemotherapy (NAC). The numbers of non-tumoral and peritumoral LVs were counted in resected specimens based on podoplanin immunostaining. The association between peritumoral LV number and clinicopathologic parameters, including tumor heterogeneity as measured by positron emission tomography, NAC response, and patient survival were analyzed. RESULTS: In non-NAC patients, the number of peritumoral LVs was highest in the lamina propria mucosa (LPM), followed by non-tumoral LVs in the LPM, peritumoral LVs in the submucosa (SM), and non-tumoral LVs in the SM. The patients with a low number of peritumoral LVs in the LPM versus those with a high number constituted a larger fraction of the NAC patients (67.8% vs. 50.0%; P = 0.022) and had a poorer pathologic response to NAC (grades 0-1a: 68.8% vs. 47.2%; P = 0.035), as well as greater tumor heterogeneity and worse survival (5-year overall survival: 50.6% vs. 72.8%; P = 0.0097). The number of peritumoral LVs in the LPM was identified as an independent prognostic factor with the highest hazard ratio (HR) of overall survival (HR 2.06; P = 0.0049) in the multivariate analysis. CONCLUSION: For EC patients, peritumoral LVs in the LPM layer are associated with tumor heterogeneity, response to NAC, and unfavorable survival.