Modification of Pathological Nodal Classification for pT1b Esophageal Squamous Cell Carcinoma With Lymphovascular Invasion: Over 10‐Year Experience

Background Lymphovascular invasion (LVI) adversely affects the survival of pT1b esophageal squamous cell carcinoma (ESCC). It is hypothesized that a modified stage classification of pT1b ESCC based on LVI may facilitate multidisciplinary therapy in LVI‐positive patients. Aims The study aims to investigate the impact of LVI on pathological nodal classification for pT1b ESCC. Methods and Results Surgically resected pT1b ESCC patients in Sun Yat‐sen University Cancer Center between 2008 and 2018 were retrospectively reviewed. Tumor sections were re‐assessed for LVI by gastrointestinal pathologists. The associations between patient survival and LVI were evaluated by the Log‐rank method. A multivariate Cox regression model was applied to identify the impact of LVI on survival. Prognostic performance was assessed by Harrell's C ‐index. A total of 424 cases with the pT1b stage were included. The risk of LVI was significantly higher in patients with nodal positive status ( p < 0.001) and larger tumor size ( p = 0.033). The 5‐year OS for LVI+ patients were 50.3% versus 78.0% for LVI− ( p < 0.001). Multivariable analyses suggested that LVI ( p = 0.021) and pN ( p = 0.016) stages were two independent adverse prognostic factors in pT1b patients. When classifying LVI+ as an independent subgroup into the pN category, the modified pN staging system demonstrated a superior prognostic performance ( p < 0.001). Conclusion Tumors with LVI should be defined as a separate subclassification to accurately classify the prognostic category in pT1b patients. Further studies are required to investigate multidisciplinary therapies for LVI+ pT1b patients.