BACKGROUND: Most risk estimations for lymph node metastasis in adenocarcinoma of the esophagus and cardia (AEC) with invasion into the muscularis mucosae (m3) or submucosa are based on surgical series. This study aimed to correlate the lymph node metastasis rate with m3 and submucosal infiltration depth of AEC in endoscopic resection specimens.
METHODS: Patients undergoing endoscopic resection for AEC between January 2000 and March 2008 at two centers were included if the endoscopic resection specimen showed m3 or submucosal cancer. Infiltration into the muscularis mucosae was defined as m3. Submucosal invasion was classified as sm1 (≤ 500 µm) or sm2/3 (> 500 µm). Exclusion criteria were chemotherapy or radiotherapy and nonradical endoscopic resection.
RESULTS: 82 patients included 57 with m3, 12 with sm1, and 13 with sm2/3 cancers. Of the tumors, 13 were poorly differentiated and five showed lymphovascular invasion. After initial endoscopic resection, seven patients underwent surgery and 75 endoscopic therapy. No lymph node metastases were found in 158 lymph nodes of the esophagectomy specimens and none of the endoscopically treated patients were diagnosed with lymph node metastasis during a median follow-up of 26 months (interquartile range [IQR] 14 - 41).
CONCLUSION: This study suggests that lymph node metastasis risk for m3 and submucosal AEC may be lower than has been assumed on the basis of surgical series, and that current guidelines are valid regarding suitability of m3 AECs for endoscopic therapy. It may also suggest that selected patients with submucosal cancers are also eligible for endoscopic management. Confirmation of these results is needed in larger series with longer follow-up.