Endoscopic resection with additional surgery versus primary surgery in T1 colorectal cancer analysis: outcomes and lymph node metastasis risk factors

Abstract Optimal management of T1 colorectal cancer (CRC) remains controversial. This study compared the long-term outcomes of endoscopic resection with additional surgical resection (ER + ASR) versus primary surgical resection (PS) in patients with T1 CRC and identified risk factors for lymph node metastasis (LNM). We conducted a retrospective cohort study involving 373 patients with T1 CRC who underwent ER + ASR or PS between January 2010 and December 2020 at a tertiary center in Taiwan. Surgical and oncological outcomes, including recurrence rates, LNM, 5-year overall survival (OS), and 5-year recurrence-free survival (RFS), were compared. Univariate and multivariate analyses identified risk factors for LNM. No significant differences were observed between the ER + ASR and PS groups in surgical outcomes, recurrence rates, LNM, 5-year OS (93% vs. 89%, P = 0.18), or 5-year RFS (89% vs. 88%, P = 0.47). Patients with ≥ 2 high-risk factors had significantly lower 5-year OS and RFS compared to those with ≤ 1 risk factor (p < 0.01). Poor histology grade and lymphovascular invasion were independent risk factors for LNM. ER + ASR and PS had comparable long-term outcomes in patients with T1 CRC. A multidisciplinary approach and standardized protocols are needed for optimal management of early-stage CRC.