Clinicopathological characteristics and endoscopic treatment efficacy of de novo early colorectal cancer / 中华消化内镜杂志

Objective:To analyze the clinicopathological features of de novo early colorectal cancer and to evaluate the efficacy of endoscopic treatment.Methods:Patients with de novo early colorectal cancer who underwent endoscopic resection in Beijing Friendship Hospital, Capital Medical University from June 2020 to May 2022 were enrolled. The baseline data, endoscopic manifestations, treatment methods, postoperative pathological results and prognosis of the patients were collected retrospectively.Results:A total of 33 patients with de novo early colorectal cancer were enrolled with the age of 62.67 ± 8.62 years, and the male to female ratio was 7.25∶1. The long diameter of lesions was 0.96 ± 0.36 cm. The lesion morphology was mainly superficial phenotype (type 0-Ⅱ), accounting for 72.7% (24/33). Endoscopic submucosal dissection (ESD) was performed in 29 cases and endoscopic mucosal resection (EMR) was performed in 4 cases. Postoperative pathology showed that 11 cases (33.3%) were well differentiated tubular adenocarcinoma, of which the superficial submucosal layer was invaded in 2 cases. Twenty cases (60.6%) were moderately differentiated tubular adenocarcinoma, of which the superficial submucosa layer was invaded in 5 cases and the deep submucosa layer in 15 cases. Two cases (6.1%) were moderately-poorly differentiated tubular adenocarcinoma, where the deep submucosa layer was invaded in both. There was significant correlation between the depth of invasion and the degree of differentiation ( P<0.001), and moderately and moderately-poorly differentiated lesions were more likely to invade the deep submucosa layer. The en bloc resection rate was 100.0% (33/33), the complete resection rate was 97.0% (32/33), and the curative resection rate was 42.4% (14/33). Among the 19 patients who did not achieve curative resection, 13 patients received supplementary surgical treatment. No tumor residue or lymph node metastasis was found in the postoperative pathology. All patients were followed up for 3-25 months, and no signs of local recurrence or metastasis were found. Conclusion:Most de novo early colorectal cancers are superficial phenotype under endoscopy. The pathology is mainly moderately differentiated tubular adenocarcinoma. Endoscopic resection of de novo early colorectal cancer shows encouraging short-term efficacy.

De Novo Submucosal Colorectal Cancer in a 3 mm Sessile Polyp / 대한소화기내시경학회지

The majority of colorectal carcinomas (95~100%) are thought to arise from adenomas. Yet colorectal carcinomas may rarely arise de novo. The popular definition of de novo carcinoma is that the lesion should consist exclusively of a carcinoma histologically and contain no adenomatous elements. Without an adenoma-carcinoma sequence, de novo carcinomas have a much higher rate of submucosal invasion, despite their small size. Their speed of growth is thought to be rapid. Some studies have shown that de novo carcinomas might arise as a macroscopically flat or depressed lesion, rather than a protruded one. However, the typical macroscopic findings of de novo carcinomas have not been established. They might be variable macroscopically and include a protruded type. We report a case of de novo colorectal carcinoma that invaded the submucosal layer involving a minute sessile polyp only 3 mm in diameter, which was removed by endoscopic mucosal resection.

Clinical Significance of Depressed-Type Colorectal Neoplasms Based on Growth and Development

A route of colorectal cancer development other than the adenoma-carcinoma sequence has recently become an issue due to the discovery of depressed-type early colorectal cancers. Moreover, the fact that some polyp-like cancers actually originate from depressed-type lesions has become obvious. Despite the protruding shapes of depressed-type early colorectal cancers, they probably have biological characteristics, which are different from those of the usual polyp lesions. We undertook this study to evaluate the clinical significance of depressed-type colorectal neoplasms. The authors recently experienced 87 cases of depressed-type colorectal neoplasms. Using Kudo's classification, we classified these 87 cases into three types based on their growth patterns, type IIc, type IIa + IIc, and type Is + IIc, and then analyzed these types on the basis of size, type, and submucosal invasion rate. The submucosal invasion rate of cancers of type IIa + IIc was significantly higher than that of type IIc (p < 0.05), and the rate for cancers of types IIa + IIc and Is + IIc together was significantly higher than that of type IIc (p < 0.05). However, no significant difference was found between the rates of types IIa + IIc and Is + IIc. In conclusion, the IIa + IIc and Is + IIc sub-types of depressed-type colorectal neoplasms, individually and together, have higher rates of submucosal invasion than type IIc lesions. Accordingly, type IIa + IIc and type Is + IIc must be differentiated from the usual polyps and should be managed cautiously, despite their protruding shapes.

Depressed-Type Early Colorectal Cancer / 대한소화기내시경학회지

BACKGROUND AND AIM: While detection and removal of polyps on the basis of the adenoma-carcinoma sequence has been a principal procedure for endoscopists, a new type of early colorectal cancer has been recognized and has become a hot issue. This new ailment is a depressed-type early colorectal cancer, which has the characteristics of rapid growth and early invasion of the submucosa. Though once considered to be mere conjecture, many researchers claim that this cancer is a de novo carcinoma despite of its rare occurrence. Recently, 4 depressed-type neoplastic lesions were presented, which signifies the importance of recognizing that this type of cancer exists and is characterized by rapid growth and early invasion of the submucosa. METHODS: The 4 recently experienced depressed neoplastic lesions were reviewed and analyzed with respect to their endoscopic and clinicopathologic characteristics. The sizes of the lesions were measured in the fully inflated state of the bowel by using an endoscopic ruler. RESULTS: The sites of predilection were the descending and sigmoid colon. All of the lesions were under 10 mm, with 75% being below 5 mm. The largest lesion was an 8-mm, well-differentiated mucosal carcinoma. The overall malignancy rate was 25%. Light redness was observed in all patients. Distortion with air transformation of the mucosal fold was also recognized in all the patients. The main treatment was endoscopic mucosal resection, which amounted to 50%. CONCLUSIONS: Depressed colorectal neoplasms are real. They can be determined by their characteristic endoscopic features, such as light redness and distortion with air transformation of the mucosal fold. Because of their characteristics of rapid growth and early invasion of the submucosa, it is important to detect and manage them in an early stage, when their sizes are below 10 mm.