Intramural Metastasis as a Risk Factor for Recurrence in Esophageal Squamous Cell Carcinoma

The purpose of this study was to assess the clinicopathologic implications of intramural metastasis (IM) in patients with esophageal squamous cell carcinoma (ESCC). We retrospectively analyzed 743 patients who underwent esophagectomy. Among these patients, IM was detected in 41 patients (5.5%). The clinicopathologic features of IM and its influence on postoperative recurrence were investigated. In total, 710 male patients and 33 female patients with a mean age of 64.4 ± 7.7 years were included. The median follow-up period was 98.5 months. IM was associated with large tumor size (p < 0.001), advanced T stage (p < 0.001), advanced N stage (p < 0.001), and advanced histologic grade (p < 0.023). IM was detected preoperatively in 51.2% of patients, and the median size of the metastasis was 2.0 cm (range: 0.1 to 6.4 cm). The median distance from the primary tumor to the metastasis was 2.5 cm (range: 0.5 to 21.0 cm); multiple metastases were observed in 46.3% of patients. Multivariable analyses revealed that advanced T stage (p < 0.001), advanced N stage (p < 0.001), and IM presence (p = 0.002) were independent risk factors for recurrence. The 5-year recurrence-free survival was 6.1% for patients with IM and 43.5% for patients without IM (p < 0.001). IM could be an important prognostic factor, along with anatomic determinants such as the TNM staging system, in patients with ESCC. Effective preoperative evaluation and postoperative surveillance may help improve the outcome of patients with ESCC, particularly when accompanied by IM.