Introduction
The standard treatment for T1b esophagogastric junctional adenocarcinoma (EGJAC) is surgery. However, surgery is highly invasive especially for elderly patients. Endoscopic submucosal dissection (ESD) is an alternative treatment of T1b cancer for such patients. However, the outcome and long-term prognosis of T1b EGJAC treated by ESD is unknown.
Aims & Methods
The aim of this study is to investigate the outcome and prognosis of T1b EGJAC treated by ESD.
Fifty lesions in 49 patients with pT1b EGJAC who underwent ESD from January 2000 to September 2019 were investigated the outcome and prognosis. The patients were divided into pT1bSM1 (n=30) and pT1bSM2 (n=20).
The patient characteristics were as follows. Male/female: 28/2, 18/2, median age: 69, 75 years old, macroscopic type (protuberance/depression): 5/25, 6/14, main histology (well differentiated (diff.)/ mixed poorly diff.): 22/8, 9/11, median diameter of resected specimen: 45, 39mm, median diameter of tumors: 22, 19mm, median follow-up period: 53, 64months, respectively. There was significant difference in only main histology (p=0.04).
EGJAC was defined as Siewert II, with T1bSM1 for ≤500 μm and T1bSM2 for >501 μm. R0 was defined as lateral and vertical margin negative, and lymph-vascular involvement negative. According to Japanese guidelines, additional treatment was recommended for all T1bSM2 cases and for SM1 lymph duct (ly)-positive and poorly diff. cases.
Results
1. Outcome of ESD
The en bloc resection rate is 100% for both T1bSM1 and T1bSM2. The R0 rate was 100% for T1bSM1 and 95% (19/20) for T1bSM2. Intraoperative perforation rate was 2% (1/50), delayed bleeding rate was 2% (1/50), and delayed perforation rate was 0%. Stenosis rate was 10% (5/50), and all of such complications were treated by endoscopy without surgery.
2. Long-term prognosis
A) T1bSM1 (n = 30)
a) One case (3%) was ly-positive. Additional surgical resection was performed, and lymph node metastasis (LNM) was observed. The patient is alive without recurrence.
b) Twenty-nine cases were ly/vascular (v) negative, and followed up without additional treatment (AT). Nineteen in 29 cases are alive without recurrence, and 10 in 29 cases died by other diseases.
c) Local recurrence rate was 0%, LNM rate was 3% (1/30), and distant metastasis (DM) rate was 0%.
B) T1bSM2 (n=20)
a) Six cases (30%) were ly and/or v positive. Additional surgical resection was performed in 3 cases, and no LNM was observed in any of the cases. Of the other 3 cases, 1 patient underwent only radiotherapy. LNM was found 14 months later, and chemotherapy was added, but treatment-related death occurred. One of the two cases who did not undergo AT had DM and multiple liver metastases 61 months after ESD, and died of the original disease despite of chemotherapy. Another patient died of other diseases.
b) Nine in 14 cases of ly/v negative underwent additional surgical resection, and no LNM was observed in any of the cases. 7 cases are alive without recurrence, and 2 cases died of other diseases. Four in 5 cases who did not undergo AT are alive without recurrence, and 1 patient died from other diseases.
c) R1 rate was 5% (1/20), local recurrence rate was 0%, LNM rate was 5% (1/20), DM rate was 5% (1/20), and mortality by primary cancer was 5% (1/20).
Conclusion
LNM and DM were not observed in the T1bSM1, ly0 group, however LNM and DM were observed in the T1bSM1,ly1 or T1bSM2 groups. Therefore, the current Japanese ESD criteria is appropriate.
The R0 resection rate for T1bSM2 was excellent at 95%, and local recurrence was 0%. ESD could be alternative treatment for patients with comorbidity.
References
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