Guidance Describes Management of Malignant Colorectal Polyps

December 23, 2020
Skylar Jeremias

Early detection of colon cancer is key to survival. New guidance advises endoscopists in identifying malignant colorectal polyps and recommendations for surgery.

New guidance released by the US Multi-Society Task Force on Colorectal Cancer (USMSTF) gives recommendations for endoscopists on how to evaluate colorectal lesions to better detect if they are cancerous.

The USMSTF includes experts from the American College of Gastroenterology, the American Gastroenterological Association, and the American Society for Gastrointestinal Endoscopy.

The authors of the guidance also discussed how these factors guide lesion management and outlined when to recommend surgery after removal of malignant polyps, which are the earliest form of clinically relevant colorectal cancer.

Colorectal polyps are the precursors for most forms of colorectal cancer, and some can mutate enough to develop high-grade dysplasia and eventually lead to invasion of dysplastic elements into the submucosa layer of colorectal tissue.

A big concern in the medical community regarding malignant polyps is whether a patient with an endoscopically resected lesion with submucosal invasion requires full surgical removal of the colorectal segment from where the lesion was removed.

Although some malignant polyps can be managed using endoscopy because of the low risk of lingering cancer in the bowel wall or lymph nodes after surgery, others are better managed by a full surgical resection because endoscopic resection is associated with a high risk of residual cancer metastases.

The guidance, developed through a literature review, aimed to address 3 topics of discussion about colorectal polyps, including: how to recognize that a polyp has invaded the submucosa and needs surgery; proper resection techniques and specimen handling when there’s an increased risk of superficial submucosally invasive polyps detected;and advice on weighing the risks and benefits of surgery when an endoscopically removed polyp is identified to have invaded the submucosa.

There are 6 recommendations outlined in the guidance.

  • Malignant polyp management must begin with a comprehensive endoscopic assessment designed to identify features associated with deep submucosal invasion.
  • In nonpedunculated lesions with feature of deep submucosal invasion, endoscopic biopsy, tattooing, and surgical resection should be conducted.
  • For nonpedunculated lesions with high superficial submucosal invasion risks, en bloc resection and proper specimen handling should be considered.
  • When pathology reports that a completely resected lesion is cancerous, the decision to recommend surgery should be based on the shape of the polyp, whether there was en bloc resection and adequate histologic evaluation, whether unfavorable histologic features are present, the risks of surgical mortality and morbidity for the patient, and what the patient wants.

The other 2 recommendations describe pathology reporting standards and also the optimal makeup of a multidisciplinary care team.

Reference

Shaukat A, Kaltenback T, Dominitz JA. Endoscopic recognition and management strategies for malignant colorectal polyps: Recommendations of the US Multi-Society Task Force on Colorectal Cancer. Am J Gastroenterol. November 1 2020;159(5):1916-1934. doi: 10.1053/j.gastro.2020.08.050