The efficacy of current-used risk factors for metastasis and the effectiveness of additional surgical resection in pT1b esophageal squamous cell carcinoma after endoscopic resection: A multi-institutional retrospective study in China

Abstract Purpose ER-treated patients with pT1b ESCC were strongly recommended to receive additional treatments, mainly radical surgical resection (SR). In view of high morbidity and mortality of additional SR treatment, this recommendation remained open to debate. Herein, our research aimed to access the efficacy of current risk predictors for metastasis based on the histological findings in ER specimens, and the effectiveness of additional SR. Methods We conducted a retrospective study of ER-treated pT1b ESCC patients with (n = 42) and without (n = 124) additional SR from 2007 to 2018 in China. Lymph node metastasis & distant organ metastasis (LNM&DOM) reflecting the overall metastasis risk of ESCC after ER treatment were used. The relationships between clinicopathological parameters and metastasis were assessed. And Overall survival(OS) and progression-free survival (PFS) were also analyzed. Results Patients with submucosal invasion depth (SMI) ≥ 200µm didn't demonstrate significant difference in LNM&DOM and survival, as compared with those with SMI < 200µm.In ER alone group, patients with vertical margin(VM) (+) showed worse PFS than those with VM(-) (p = 0.008).More strikingly, for patients in low-risk group who had LVI(-) and VM(-), ER + SR didn't significantly prolong their PFS(p = 0.120) but significantly shorter their OS (p < 0.010) as compared with ER alone treatment. Conclusions SMI ≥ 200µm isn’t a sensitive and predictive indicator for both LNM&DOM and survival for patients with ER treatment. More strikingly, additional SR is not an optimal therapeutic selection for ER-treated pT1b ESCC in low-risk group who had LVI(-) and VM(-).