Achieving adequate lymph node dissection in treating esophageal squamous cell carcinomas by radical lymphadenectomy: Beyond the scope of numbers of harvested lymph nodes

: Previous studies have recommended harvesting a large number of lymph nodes (LNs) to improve the survival of patients with esophageal squamous cell carcinoma (ESCC). These studies or clinical guidelines focus on the total harvested LNs during lymphadenectomy; however, the extent of LN dissection (LND) required in patients with ESCCs remains controversial. The present study proposed a novel individualized adequate LND (ALND) strategy to compliment current guidelines to improve individualized therapeutic efficacy. For N0 cases, ALND was defined as an LN harvest of >55% of the LNs from nodal zones adjacent to the tumor location; and for N+ cases, ALND was defined as 8, 8, 8, 8 or 16 LNs dissected from the involved cervical, upper, middle, lower and celiac zones, respectively. Retrospective analysis of the ESCC cohort revealed that the ALND was associated with improved patient survival [hazard ratio (HR)=0.45 and 95% CI=0.30-0.66)]. Stratified analyses revealed that the protective role of ALND was prominent, with the exception of higher pN+ staged (pN2-3) cases (HR=0.52, 95% CI=0.23-1.18). Furthermore, ALND was associated with improved survival in local diseases (T1-3/N0-1; HR=0.50, 95% CI=0.30-0.84) and locally advanced diseases (T4/Nany or T1-3/N2-3; HR=0.32, 95% CI=0.15-0.68). These findings suggested that the proposed ALND strategy may effectively improve the survival of patients with ESCC.