背景和目的：2022年日本食管癌诊疗指南将T1a-EP/LPM作为内镜切除术绝对适应证，T1a-MM/T1b-SM1作为相对适应证，而T1b-SM2不作为适应证。但在患者个人希望和全身状态差的情况下，也可采用内镜黏膜下剥离术（endoscopic submucosal dissection，ESD）治疗。因此，我们针对术后病理证实pT1b期食管鳞癌的人群进行了一项单中心回顾性研究，并进行了长期的随访，旨在：1）探讨影响淋巴结转移（lymph node metastasis，LNM）的危险因素，确定影响该人群预后的临床病理学特征；2）对浸润深度进行深度解析，确定影响该人群预后的浸润深度界值；3）比较在ESD后，追加治疗对比未追加治疗的患者的预后情况；4）比较在追加治疗后，接受单纯放疗（radiotherapy，RT）和/或化疗、接受外科手术以及未接受治疗的患者的预后情况。

方法：本研究纳入了在2013年4月至2019年4月期间于中国医学科学院肿瘤医院接受治疗的pT1b期食管癌患者。所有患者均被病理诊断为pT1b食管鳞状细胞癌（esophageal squamous cell carcinoma，ESCC）。1）通过对该人群的临床病理学因素进行Cox多因素分析以明确影响无复发生存（relapse free survival，RFS）的潜在预后因素；2）使用Kaplan-Meier分析比较追加治疗以及未追加治疗患者的预后情况，并对不同的人群进行亚组分析；3）在总体人群中，探究浸润深度界值对RFS及总生存期（overall survival，OS）的影响。

结果：本研究共纳入107名连续的pT1b期ESCC患者，针对RFS的中位随访时间为70.8个月。浸润深度 ≥ 500um、脉管瘤栓（lymphovascular invasion，LVI）及垂直切缘（vertical margin，VM）阳性是影响LNM的独立因素，进一步的预后分析显示浸润深度 ≥ 500um是影响RFS的独立因素。在追加治疗策略选择方面，与追加治疗相比，未追加治疗具有相似的RFS（HR = 1.02，P = 0.996）及OS（HR = 1.50，P = 0.366）结局。与未追加治疗相比，追加外科手术、追加放疗联合化疗显示出了相似的RFS（P = 0.744）。

结论：pT1b期食管鳞癌患者ESD的整块完全切除率为95.3%，有很好的疗效。对于该人群，未追加治疗的长期预后结局可与追加治疗相媲美。浸润深度 ≥ 500um是该人群的独立预后因素。对于浸润深度 < 500um的患者，定期随访不失为一种可选的有效管理策略。

Background: The optimal additional management and potential prognostic factors for patients with pT1b esophageal squamous cell carcinoma are still unclear. We conducted a real-world study in this special population to identify clinical-pathological factors of potential prognostic value and to compare the efficacy of different adjuvant strategies.

Methods: We included patients with pT1b esophageal cancer of esophageal squamous cell carcinoma (ESCC) histology treated at the Cancer Hospital, Chinese Academy of Medical Sciences from April 2013 to April 2019. We performed logistic analysis to identify potential prognostic factors for lymph node metastasis (LNM). We also compared survival outcomes of 1) patients treated with additional chemotherapy and/or radiotherapy or esophagectomy, or observation；2) patients with deeper submucosal invasion receiving additional therapy (ADT) or observation.

Results: Overall, 107 consecutive patients were included, with a median follow-up of 70.8 months for RFS. ≥500um, LVI+, and VM+ were identified as independent prognostic factors of LNM. For management, compared with observation alone, ADT couldn’t significantly benefit patients (HR=1.02, P=0.996). Meanwhile, patients did not benefit significantly from chemoradiotherapy compared with those who received esophagectomy alone or chemoradiotherapy (HR = 1.50, P = 0.366). Patients who received surgical regimen showed similar RFS compared with additional radiotherapy and/or chemotherapy (HR = 1.74, P = 0.242).

Conclusions: Long-term follow up can be an optional strategy for pT1b ESCC patients with submucosal invasion depth less than 500um. SM invasion depth ≥ 500um is an independent prognostic factor of RFS for this population.