Effect of Neoadjuvant Chemoradiotherapy on Lymph Node Micrometastases in Thoracic Esophageal Cancer

Aim: The purpose of this study was to clarify the effect of neoadjuvant chemoradiotherapy (nCRT) on lymph node micrometastasis (LNM) in esophageal squamous cell carcinoma (ESCC). Patients and Methods: The therapeutic efficacy of nCRT was analyzed in 41 ESCC patients randomized to the Surgery group (n=21) and the nCRT group (n=20). Lymph node specimens from patients were classified into two categories, micrometastasis (MM) and tumor cell microinvolvement (MI), after immunohistochemical evaluation. Results: The incidence rates of patients presenting MM with or without MI or MI alone in the Surgery group were significantly higher than those in the nCRT group. The 10-year survival rate of 15 patients with simultaneous histological metastasis (HM) and LNM was significantly lower than that in the 26 patients without LNM. Within the nCRT group, the 10-year survival rates of patients with versus those without HM were not significantly different; however, the 10-year survival rate of the 5 patients with simultaneous HM and LNM was significantly lower than that of the 15 patients without LNM. Conclusion: ESCC patients with LNM may benefit from nCRT, and evaluation of the simultaneous presence of HM and LNM may facilitate accurate prediction of survival in ESCC patients.