Adequate lymphadenectomy in patients with oesophageal squamous cell carcinoma: resecting the minimal number of lymph node stations.

OBJECTIVES

The seventh edition of the American Joint Committee on Cancer (AJCC) tumour-node-metastasis (TNM) staging system for oesophageal cancer did not define the minimal requirement for an adequate extent of lymphadenectomy in patients with oesophageal cancer. This study aimed to define the minimum number of lymph node (LN) stations to be resected in patients with oesophageal squamous cell carcinoma (OSCC).

METHODS

We conducted a retrospective review of clinicopathological data from 2033 patients with OSCC undergoing complete resection between August 2005 and September 2013. An ordinal logistic regression analysis was used to identify the variables associated with revised N (rN) staging progression and indices that could be used in the stratified analysis. To determine the optimal number of resected LN stations, we compared the overall survival hazard ratio between groups with different numbers of LN stations using a Cox's proportional hazards regression model. The highest χ(2) value was deemed the cut-off point.

RESULTS

The progression of rN staging was influenced by T-staging, G-staging, tumour length (>3 cm), lymphovascular invasion and number of resected LN stations. According to Cox's proportional hazards regression model, we recommended that at least six LN stations should be removed. Then, we conducted a stratified analysis by G status and tumour length. We found that at least seven LN stations should be removed in patients with G3 or tumour length >3 cm.

CONCLUSIONS

For thoracic OSCC, at least six LN stations had to be removed. Furthermore, for patients with G3 or tumour length >3 cm, the recommendation was seven.