Recurrence rate and lesions characteristics after cold snare polypectomy of high‐grade dysplasia and T1 lesions: A multicenter analysis
Naohisa Yoshida, Kohei Fukumoto, Daisuke Hasegawa, Yoshikazu Inagaki, Ken Inoue, Ryohei Hirose, Osamu Dohi, Kiyoshi Ogiso, Takaaki Murakami, Akira Tomie, K Okuda, Yutaka Inada, Takashi Okuda, Rafiz Abdul Rani, Yukiko Morinaga, Mitsuo Kishimoto, Yoshito Itoh
Abstract
BACKGROUND AND AIM: High-grade dysplasia (HGD) and T1 lesions are accidentally resected by cold snare polypectomy (CSP) and the characteristics, and follow-up of them has not been reported. In this study, we analyzed the histopathological findings and recurrence of them. METHODS: This was a multicenter retrospective-cohort study. We collected HGD and T1 lesions of ≤ 10 mm resected by CSP among 15 520 patients receiving CSP from 2014 to 2019 at nine related institutions, and we extracted only cases receiving definite follow-up colonoscopy after CSP of HGD and T1 lesions. We analyzed these tumor's characteristics and therapeutic results such as R0 resection and local recurrence and risk factors of recurrence. RESULTS: We collected 103 patients (0.63%) and extracted 80 lesions in 74 patients receiving follow-up colonoscopy for CSP scar. Mean age was 68.4 ± 12.0, and male rate was 68.9% (51/80). The mean tumor size (mm) was 6.6 ± 2.5, and the rate of polypoid morphology and rectum location was 77.5% and 25.0%. The rate of magnified observation was 53.8%. The rates of en bloc resection and R0 resection were 92.5% and 37.5%. The local recurrence rate was 6.3% (5/80, median follow-up period: 24.0 months). The recurrence developed within 3 months after CSP for four out of five recurrent cases. Comparing five recurrent lesions to 75 non-recurrent lesions, a positive horizontal margin was a significant risk factor (60.0% vs 10.7%, P < 0.001). CONCLUSIONS: High-grade dysplasia and T1 resected by CSP were analyzed, and the local recurrence rate of them was substantially high.