Prognostic factors for survival in esophageal squamous cell carcinoma (ESCC) patients with a complete regression of the primary tumor (ypTO) after neoadjuvant chemoradiotherapy (NCRT) followed by surgery

Background: There are also differences in survival prognosis among esophageal squamous cell carcinoma (ESCC) patients with a complete regression of the primary tumor (ypT0) after Neoadjuvant chemoradiotherapy (NCRT) followed by surgery. And the purpose of this study was to investigate influencing factors from these different prognostic outcomes and their possible causes. Methods: The clinical data of 88 cases of ESCC patients with ypT0 after NCRT followed by surgery between 2011 and 2019 were retrospectively analyzed. The clinical and pathological prognostic factors that affect the survival were analyzed. Results: Sex, number of lymph nodes dissected, and pathologic positivity of lymph nodes may be significant in univariate analysis (P<0.1). Further multivariate analysis suggested that the pathologic positivity of the lymph nodes was an independent factor affecting prognosis (HR: 4.757, 95% CI: 2.195-10.313, P=0.000). Subsequently, the whole group was divided into a positive lymph node group (group LN+) and a negative lymph node group (group LN-) for comparison. The overall survival (OS) of group LN+ was significantly worse (HR: 0.211, 95% CI: 0.0336-0.239; P<0.0001), and recurrence-free survival (RFS) was significantly poorer in the LN+ group (HR: 0.0679, 95% CI: 0.0239-0.1923, P<0.0001). There were 14 cases of recurrence and metastasis in the LN+ group (14/21, 66.7%) and 10 cases in the group LN- (10/67, 14.9%). Among the sites of recurrence and metastasis, there were 10 (10/14, 71.4%) and 4 (4/14, 28.6%) cases of distant metastasis, respectively, and 4 (4/14, 28.6%) cases of local metastasis in the LN+ group; meanwhile, there were 8 (8/10, 80.0%) cases of distant metastasis and 2 (2/10, 20.0%) cases of local metastasis in the LN- group. Conclusions: The independent risk factor for survival prognosis in ESCC patients with ypT0 after NCRT followed by surgery was positive postoperative pathological lymph nodes. The reason for the shortened survival time associated with this group of patients was their susceptibility to recurrence and metastasis.