Adjuvant therapy for pT1a-m3/pT1b esophageal squamous cell carcinoma after endoscopic resection: Esophagectomy or chemoradiotherapy? A critical review

•ER followed by adjuvant therapy can be a new treatment option.•Adjuvant esophagectomy is better than adjuvant CRT in terms of tumor recurrence.•Tumor with invasion to ≥ sm2 plus lymphovascular invasion is a high-risk of relapse.•Patients with a high-risk should be treated with adjuvant esophagectomy.•Patients with a nonhigh risk can be treated with adjuvant chemoradiotherapy.