Pathological Predictors for Defining a Therapeutic Strategy for Early Colon Cancer after Endoscopic Resection: Multicenter Retrospective Analysis from Surgically Resected Specimens.

BACKGROUND/AIMS: For the possibility of regional lymph node metastasis (LNM), early colon cancer (ECC) is a boundary lesion between endoscopic resection and surgery. The aim of study is to clarify risk factors for LNM and to determine therapeutic strategy after endoscopic resection in patients with ECC. METHODOLOGY: The histopathology of patients with ECC underwent surgery with LN dissection in 8 university hospitals were reviewed by experienced pathologist blinded to LN status. RESULTS: In total, 370 patients (107 with mucosal cancer, 263 with submucosal invasive colorectal carcinoma [SICC]) were enrolled. Excluding mucosal cancer, the LNM rate was 11.8% (31/263, including 15.4% [8/52] with pedunculated SICC [P-SICC] and 10.9% [23/211] with non-pedunculated SICC [NP-SICC]). Multivariate analysis showed that tumor sprouting (P < 0.001; odds ratio [OR], 8.83; 95% confidence interval [CI], 3.04-25.69), submucosal invasion depth (SM depth) > 2000 µm (P = 0.024; OR, 3.68; 95% CI, 1.19-11.37), and lymphatic invasion (P = 0.022; OR, 3.48; 95% CI, 1.19-10.13) were related to LNM. All LNMs with SM depth < 2000 µm showed tumor sprouting without lymphatic invasion. CONCLUSIONS: Significant risk factors for predicting LNM in patients with SICC were tumor sprouting, SM depth > 2000 µm, and lymphatic invasion.