USMSTF Releases New Guidelines on Management of Malignant Colorectal Polyps

The US Multisociety Task Force on Colorectal Cancer (USMSTF) has released new guidance for endoscopists on how to assess lesions for endoscopic features associated with cancer, discuss how these factors guide endoscopic management, and to outline the factors that frame whether to advise surgery after a malignant polyp has been endoscopically resected.¹

Of note, the USMSTF consists of gastroenterologists with expertise in colorectal neoplasia (ie, colorectal cancer [CRC] and precursor lesions, such as polyps). The American College of Gastroenterology, the American Gastroenterological Association, and the American Society for Gastrointestinal Endoscopy are each represented by the task force.

“Malignant polyps represent the earliest form of clinically relevant CRC in most patients because neoplastic invasion of the submucosa allows for possible lymphatic and vascular metastasis. The risk of metastasis depends on several endoscopic and histologic features,” the authors of the guidance wrote. “The clinical issue most often raised by malignant polyps is whether a patient with an endoscopically resected colorectal lesion with submucosal invasion requires surgical resection of the colorectal segment from which the lesion was removed.”

“Optimal selection of patients with malignant polyps for endoscopic surveillance vs surgical treatment is important to minimize both the risk of residual cancer and the risk of surgery,” added the authors.

The guidance, published in Gastroenterology, was formulated around several specific key questions with relevant data that inform the recommendations. Specifically, the authors of the guidance discussed 6 questions that address the following 3 tasks:

• endoscopic recognition of colorectal polyps with deep submucosal invasion that should be referred directly to surgery;
• optimal endoscopic resection techniques and specimen handling when an increased risk of superficial submucosally invasive polyp is identified;
• and weighing the risks and benefits of surgery when an endoscopically removed polyp is found to have submucosal invasion.

In addition, the document also discusses optimal resection techniques for large and malignant polyps. However, this document excluded management of polyps associated with inflammatory bowel disease.

The USMSTF graded the quality of evidence and strength of recommendations using an adaptation of the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach. The GRADE process categorizes the quality of the evidence as high, moderate, low, or very low.

More specifically, the GRADE process involved the collection of literature, analysis, summary, and a separate review of the quality of evidence and strength of recommendations. The USMSTF members employed a modified, qualitative approach for this assessment based on exhaustive and critical review of evidence, without a traditional meta-analysis.

The GRADE process separated evaluation of the quality of the evidence to support a recommendation from the strength of that recommendation. This was done in recognition of the fact that other factors can influence a recommendation, such as side effects, patient preferences, values, and cost.

Strong recommendations within the guidelines mean that most informed patients would choose the recommended management and that clinicians can structure their interactions with patients accordingly. Weak recommendations mean that patients’ choices will vary per their values and preferences, and clinicians must ensure that patient care is in keeping with their values and preferences.

Importantly, though CRC is the second leading cause of cancer death in the US, CRC is preventable when precancerous polyps are found and removed before they turn into cancer.² With routine screening for CRC, the American Gastroenterological Association indicated that more than one-third of CRC deaths can be avoided.

Screening for average-risk patients is recommended to begin at age 50, and earlier for patients with risk factors or family history.

References:

1. Shaukat A, Kaltenbach T, Dominitz JA, et al. Endoscopic Recognition and Management Strategies for Malignant Colorectal Polyps: Recommendations of the US Multi-Society Task Force on Colorectal Cancer. Gastroenterology. doi: 10.1053/j.gastro.2020.08.050

2. Experts release new management strategies for malignant colorectal polyps [news release]. Bethesda, Maryland. Published November 4, 2020. Accessed November 30, 2020. https://gastro.org/press-releases/experts-release-new-management-strategies-for-malignant-colorectal-polyps-2/