T1 esophageal squamous cell carcinoma (ESCC) has a low, but still present, risk of lymph node (LN) metastasis. Endoscopic mucosal resection (EMR) or endoscopic submucosal dissection (ESD) is often applied for T1 ESCC. To achieve successful treatment by EMR/ESD, the risk of LN metastases, LN recurrence, and hematological recurrence need to be better understood. The aim of this study was to determine the precise risk for metastasis in T1 ESCC.
We divided 295 patients with T1 ESCC who underwent surgery and/or ESD/EMR into 6 categories (m1, m2, m3, sm1, sm2, and sm3). Their risks of LN metastasis, LN recurrence, hematological recurrence, and the outcome were determined.
The rates of LN metastasis and LN recurrence were 0% in m1 and m2, 9% in m3, 16% in sm1, 35% in sm2, and 62% in sm3 cases. The incidence of hematological recurrence was 0% in m1, m2, m3, and sm1 cases; 9% in sm2 cases; and 13% in sm3 cases. The overall risk of metastasis was 9% in m3, 16% in sm1, 38% in sm2, and 64% in sm3 patients. The 5-year disease-specific survival rates were 100% in m1, m2, and m3; 90.9% in sm1; 78.8% in sm2; and 68.6% in sm3 patients. Statistically, both lymphatic and venous invasion were selected as predictive markers for metastasis. In m3 patients, positivity for either of these had an odds ratio for metastasis of 7.333 (P = 0.093).
Our study provides a precise assessment of the comprehensive risk of metastasis and feasible predictive markers for T1 ESCC.