Outcomes of patients receiving additional esophagectomy after endoscopic resection for clinically mucosal, but pathologically submucosal, squamous cell carcinoma of the esophagus.

Purpose: This study investigated the actual rate or extent of lymph node metastasis or the survival outcomes among patients that underwent esophagectomy with lymph node dissection after ESD for clinical mucosal, but pathological submucosal, esophageal cancer.

Methods: Seventeen patients that received esophagectomy with two- or three-field lymph node dissection as additional treatment after ESD for clinical mucosal, but pathological submucosal, esophageal cancer between 2006 and 2010 were analyzed. The rate and extent of lymph node metastasis and the patient outcomes were determined.

Results: The tumor depths were diagnosed as SM1 in 8 (47 %) patients and SM2 in 9 (53 %), based on the analyses of resected specimens. Lymphatic invasion was evident in 13 (76 %) patients, while venous invasion was detected in 5 (29 %). Five (29 %) patients had pathologically detected lymph node involvement. Seven (0.8 %) of the 890 dissected nodes showed cancer involvement. Three patients had one involved node in the mediastinum or abdomen, and 2 patients had 2 involved nodes in the abdomen. The patients were followed up for 11-71 months (median 23 months), and all were alive without recurrence at the final follow-up.

Conclusion: Twenty-nine percent of the patients diagnosed with clinically mucosal, but pathologically submucosal, thoracic squamous cell esophageal cancer after ESD had 1-2 cancer-involved lymph nodes in the lower mediastinum and abdomen. Esophagectomy with lymph node dissection is therefore considered to be a necessary and effective additional treatment for these patients.