[A Study of Surgical Additional Resection Cases after Endoscopic Resection for Colorectal Cancer]

In cases of colorectal cancer diagnosed as pT1 after endoscopic resection, surgical additional resection is considered due to the potential risk of lymph node metastasis. However, approximately 90% of such cases do not exhibit lymph node metastasis. Recently, the increase in the elderly population has led to a rise in patients with poor performance statu(s PS), complicating the decision-making process for additional resection. In this study, we retrospectively reviewed 35 cases that underwent surgical additional resection following endoscopic resection between January 2019 and December 2024 at our institution. Lymph node metastasis was observed in 3 cases(8.6%). Among 20 cases with multiple indications for additional resection, 3 cases(15.0%)had lymph node metastasis. Additionally, among the 8 cases with positive resection margins, 2 cases (25.0%)had lymph node metastasis. No recurrences were observed during the follow-up period. Given the higher incidence of lymph node metastasis in cases with multiple risk factors or positive resection margins, surgical additional resection is considered advisable in such cases.