Comparison of lymph node metastasis pattern from esophagogastric junction adenocarcinoma versus very low thoracic esophageal squamous cancer: a propensity-matched analysis.

BACKGROUND

The anatomical locations of esophagogastric junction adenocarcinoma (AEG) and very low thoracic esophageal squamous cell carcinoma (ESCC) are similar. This study aimed to evaluate the difference in lymph node metastasis (LNM) distribution between AEG and very low thoracic ESCC.

METHODS

Data from 156 Siewert I-II AEG patients and 120 ESCC patients with proximal edges located within 5 cm of the esophagogastric junction (EGJ) and underwent curative surgery from 2010 to 2015 were retrospectively analyzed using propensity score matching (PSM). Five or six baseline variables were included in PSM separately. All patients underwent curative transthoracic surgery and systematic lymphadenectomy. After PSM, LNM rates of major stations were compared using the chi-squared test or Fisher's exact test.

RESULTS

After PSM was performed with covariates (age, sex, T stage, grade, tumor length), 60 pairs of patients were included. The lower mediastinal and total thoracic LNM rates of ESCC were significantly higher than those of AEG (18.3% 3.3%, P=0.019; 25% 3.3%, P=0.002). After further addition of the N stage as a variant to the previous PSM model, we found that the paracardial LNM distribution was significantly different between ESCC and AEG patients (36.1% 19.7%, P=0.043). Among all tumor characteristics, only the T stage was positively correlated with paracardial LNM in ESCC (P=0.010), but not in AEG. In AEG, the median survival was poor for patients with thoracic LNM.

CONCLUSIONS

Patients with very low thoracic ESCC exhibit stronger metastatic ability in the lower mediastinal and paracardial nodes than Siewert I-II AEG. However, the pathological metastasis of AEG in thoracic nodes was associated with poor survival outcomes.