New 3-Tiered Circumferential Resection Margin Criteria in Esophageal Squamous Cell Carcinoma

We aimed to investigate the optimal cutoff value of circumferential resection margin (CRM) of esophageal squamous cell carcinoma (ESCC) in patients who underwent radical esophagectomy.

Tumor involvement of a CRM in ESCC has not been clearly defined.

We reviewed 479 pT3 ESCC patients to find the optimal cutoff point of distance from CRM in addition to 0 μm for discriminating survival time.

The partitions at and near the 500 μm distance from CRM generated the largest log-rank statistics (P = 0.0086). Therefore, we added 500 μm as an additional cutoff value for a positive CRM. Compared to patients with CRM greater than 500 μm, patients with CRM 0 μm showed worse overall survival (P < 0.001) and progression-free survival (P < 0.001), followed by patients with 0 to 500 μm (P = 0.008 and 0.066, respectively). In multivariable analyses, overall survival differences remained significant [0 < CRM ≤ 500 μm vs CRM > 500 μm, hazards ratio (HR) = 1.875, 97.5% CI: 1.243-2.829, P = 0.002; CRM = 0 μm vs CRM > 500 μm, HR = 2.666, 97.5% CI: 1.745-4.076, P < 0.001]. In comparison of criteria from the College of American Pathologists, the Royal College of Pathologists, and this study, HRs of positive CRM (95% CI, P-value) were 1.969 (1.501-2.584, P < 0.001), 1.384 (1.039-1.844, P = 0.027), and 1.696 (1.342-2.143, P < 0.001), respectively.

In patients with ESCC, we developed new, 3-tiered CRM criteria providing more detailed prognostic information than the 2-tiered criteria.