Optical evaluation: the crux for effective management of colorectal neoplasia

Colorectal polypectomy and endoscopic mucosal resection: European Society of Gastrointestinal Endoscopy (ESGE) Guideline - Update 2024

1:  ESGE recommends cold snare polypectomy (CSP), to include a clear margin of normal tissue (1-2 mm) surrounding the polyp, for the removal of diminutive polyps (≤ 5 mm).Strong recommendation, high quality of evidence. 2:  ESGE recommends against the use of cold biopsy forceps excision because of its high rate of incomplete resection.Strong recommendation, moderate quality of evidence. 3:  ESGE recommends CSP, to include a clear margin of normal tissue (1-2 mm) surrounding the polyp, for the removal of small polyps (6-9 mm).Strong recommendation, high quality of evidence. 4:  ESGE recommends hot snare polypectomy for the removal of nonpedunculated adenomatous polyps of 10-19 mm in size.Strong recommendation, high quality of evidence. 5:  ESGE recommends conventional (diathermy-based) endoscopic mucosal resection (EMR) for large (≥ 20 mm) nonpedunculated adenomatous polyps (LNPCPs).Strong recommendation, high quality of evidence. 6:  ESGE suggests that underwater EMR can be considered an alternative to conventional hot EMR for the treatment of adenomatous LNPCPs.Weak recommendation, moderate quality of evidence. 7:  Endoscopic submucosal dissection (ESD) may also be suggested as an alternative for removal of LNPCPs of ≥ 20 mm in selected cases and in high-volume centers.Weak recommendation, low quality evidence. 8:  ESGE recommends that, after piecemeal EMR of LNPCPs by hot snare, the resection margins should be treated by thermal ablation using snare-tip soft coagulation to prevent adenoma recurrence.Strong recommendation, high quality of evidence. 9:  ESGE recommends (piecemeal) cold snare polypectomy or cold EMR for SSLs of all sizes without suspected dysplasia.Strong recommendation, moderate quality of evidence. 10:  ESGE recommends prophylactic endoscopic clip closure of the mucosal defect after EMR of LNPCPs in the right colon to reduce to reduce the risk of delayed bleeding.Strong recommendation, high quality of evidence. 11:  ESGE recommends that en bloc resection techniques, such as en bloc EMR, ESD, endoscopic intermuscular dissection, endoscopic full-thickness resection, or surgery should be the techniques of choice in cases with suspected superficial invasive carcinoma, which otherwise cannot be removed en bloc by standard polypectomy or EMR.Strong recommendation, moderate quality of evidence.

T1 colorectal cancer management in the era of minimally invasive endoscopic resection

T1 colorectal cancer (CRC), defined by tumor invasion confined to the submucosa, has historically been managed by surgery. Improved understanding of recurrence and lymph node metastases risk, coupled with advances in endoscopic resection techniques, have led to an increasing capacity for organ-sparing local excision. Minimally invasive management of T1 CRC begins with optical evaluation of the lesion to diagnose invasive disease and quantify depth of invasion, which informs therapeutic decision making. Modality selection between various available endoscopic resection techniques depends upon lesion characteristics, technique risk-benefit profiles, and location-specific implications. Following endoscopic resection, established histopathology features determine the risk of recurrence and subsequent management including surveillance or adjuvant surgical excision. The management of non-operative candidates deviates from conventional recommendations with emerging treatment strategies in select populations.

Endoscopic Treatment of T1 Colorectal Cancer

Commonly accepted criteria for curative resection of T1 colorectal cancer include R0 resection with horizontal and vertical clear margins (R0), absence of lympho-vascular or vessel infiltration (L0, V0), a low to moderate histological grading (G1/2), low tumor cell budding, and limited (<1000 µm) infiltration into the submucosa. However, submucosal infiltration depth in the absence of other high-risk features has recently been questioned as a high-risk situation for lymph-node metastasis. Consequently, endoscopic resection techniques should focus on the acquisition of qualitatively and quantitively sufficient submucosal tissue. Here, we summarize the current literature on lymph-node metastasis risk after endoscopic resection of T1 colorectal cancer. Moreover, we discuss different endoscopic resection techniques with respect to the quality of the resected specimen.

Incremental benefit of dye-based chromoendoscopy to predict the risk of submucosal invasive cancer in large nonpedunculated colorectal polyps

BACKGROUND AND AIMS

Detailed lesion assessment of large nonpedunculated colorectal polyps (LNPCPs; ≥20 mm) can help predict the risk of submucosal invasive cancer (SMIC). Traditionally this has required the use of dye-based chromoendoscopy (DBC). We sought to assess the accuracy and incremental benefit of DBC in addition to high-definition white-light imaging (HDWLI) and virtual chromoendoscopy (VCE) for the prediction of SMIC within LNPCPs.

METHODS

A prospective observational study of consecutive LNPCPs at a single tertiary referral center was performed. Before resection all lesions were assessed for the presence of a demarcated area (DA), defined as an area of disordered pit or microvascular pattern, by 2 trained endoscopists before and after DBC. Diagnostic performance characteristics were calculated with histology as the reference criterion standard, and overall agreement was calculated using the κ statistic.

RESULTS

Over 39 months to March 2021, 400 consecutive LNPCPs (median lesion size, 35 mm; interquartile range, 25-45) were analyzed. The overall rate of SMIC was 6.5%. Presence of a DA had an accuracy of 91% (95% confidence interval, 87.7-93.5) for SMIC, independent of the use of DBC. The rate of interobserver agreement for presence of a DA using HDWLI + VCE was very high (κ = .96) with no benefit gained by the addition of DBC.

CONCLUSIONS

The use of HDWLI and VCE is likely to be adequate for lesion assessment for the prediction of SMIC among LNPCPs. Further, the absence of a DA is strongly predictive for the absence of SMIC, independent to the use of DBC. (Clinical trial registration number: NCT03506321.).

Colorectal malignant polyps: a modern approach

Colorectal malignant polyps (MP) are polyps with invasive cancer into the submucosa harboring a variable risk of lymph node involvement, which can be estimated through evaluation of morphological, endoscopic, and histologic features. The recent advances in imaging endoscopic techniques have led to the possibility of performing an optical diagnosis of T1 colorectal cancer, allowing the selection of the best therapeutic modality to optimize outcomes for the patient. When MP are diagnosed after endoscopic removal, their management can be challenging. Differentiating low- and high-risk histologic features that influence the possibility of residual tumor, the risk of recurrence and the risk of lymph node metastasis, is crucial to further optimize treatment and surveillance plans. While the presence of high-risk features indicates a need for surgery in the majority of cases, location, comorbidities and the patient’s preference should be taken in account when making the final decision. This is a particularly important issue in the management of low rectal MP presenting with high-risk features, where chemoradiotherapy followed by a watch-and-wait strategy has demonstrated promising results. In this review we discuss the important prognostic features of MP and the most modern approaches regarding their management.