| BackgroundEarly colorectal cancer(ECC)includes intramucosal carcinoma(Tis)and submucosal carcinoma(T1).Intramucosal carcinoma metastasizes to lymph node rarely,whereas 8%-16%of submucosal carcinoma metastasizes to lymph nodes.Some patients of ECC could be achieved curative resection by endoscopy.Clinical practice guideline 2020 for the treatment of colorectal cancer in China recommends that intramucosal carcinoma and submucosal superficial invasive carcinoma can be treated endoscopically.Additional surgery is recommended if positive vertical resection margin or any of the high-risk factors for lymph node metastasis is observed in the resected specimen of pTl,such as depth of submucosal invasion≥1000μm,lymphovascular invasion,poorly differentiated adenocarcinoma/mucinous carcinoma/signet-ring cell carcinoma,tumor budding.If no above risk factors,endoscopic treatment could be considered.However,there are still some controversies about the management of ECC like definition of positive margins and measurement of depth of submucosal invasion.And some researchers have found some lesions with submucosal invasion depth≥1000μm could be treated well by endoscopic treatment.ObjectiveTo investigate the efficacy of endoscopic therapy for ECC and the risk factors affecting the recurrence of ECC after endoscopic resection.MethodsWe conducted a retrospective study including 391 patients of ECC pathologically diagnosed after endoscopic resection in Headquarters and Zengcheng Branch of Nanfang Hospital,Southern Medical University from January 2009 to July 2021.Every patient should complete preoperative imaging examination to preliminarily exclude lymph node and distant metastasis,and take appropriate endoscopic treatment according to the characteristics of the lesions.Additional surgery is recommended if high-risk factors for lymph node metastasis are found pathologically after endoscopic resection.Long-term follow up was required closely if high-risk factors are not found or surgery is refused due to their personal reasons.After data collection,the recurrencefree survival rate of ECC was analyzed,and the risk factors affecting the recurrence after endoscopic resection were explored.Results1)Patient enrollment:391 patients of ECC pathologically diagnosed were enrolled,including 319 patients of intramucosal carcinoma,17 patients of submucosal superficial invasive carcinoma(Tla),55 patients of submucosal deep invasive carcinoma(T1b).2)Treatment condition:14 patients(3.6%)had found delayed bleeding and 6 patients(1.53%)had found perforation after endoscopic resection.The curative resection rate after endoscopic resection was 82.1%.22 patients of intramucosal carcinoma had no residual after additional surgery,29 patients of submucosal carcinoma had found 4 residual cancer and 1 residual cancer with lymph node metastasis after additional surgery.3)Evalution of Risk factor:There were 8 cases with positive vertical margin,6 cases with poorly differentiated adenocarcinoma/mucinous carcinoma/signet-ring cell carcinoma,55 cases with the depth of submucosal invasion≥1000μm,1 case with lymphovascular invasion,and 2 cases with high grade tumor budding in the submucosal carcinoma group.4 residual tumors were found when 6 cases with positive vertical margin were performed additional surgery.4)Efficacy analysis:384 patients of ECC were followed up.The mean follow-up time was(46.18±36.83)months.The overall disease-free survival rate for ECC was 99.4%.The disease-free survival rate for high-risk T1 lesions was 95.1%.The diseasefree survival rate was 91.1%after endoscopic treatment only and 100%with additional surgery after endoscopy,which was not significant different(P=0.198).Dividing the lesions with only one high-risk factor of T1b into low-risk T1b,the disease-free survival rate of the low-risk T1b was 90.4%after endoscopic treatment only and 100%with additional surgery after endoscopy,which was not significant different(P=0.352).During the follow-up,16 cases with the depth of submucosal invasion 1000-2000μm had no recurrence,2 patients with only one risk factor that the depth of submucosal invasion 5391 μm and 2670 μm respectively developed recurrence and lymph node metastasis after endoscopic treatment only.ConclusionEndoscopic treatment for ECC is safe and could achieve good efficacy.Additional surgery is recommended if positive vertical resection margin is observed in the resected specimen of ECC.Meanwhile,ECC with only one risk factor may achieved good effect after endoscopic resection,which is the depth of submucosal invasion≥1000μm.ECC with only the risk factor of submucosal invasion depth of 1000 μm to 2000 μm has a lower risk of recurrence after endoscopic treatment,so endoscopic treatment could be considered and close follow-up is required. |
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