In recognition of National Colorectal Cancer Awareness Month, GIE: Gastrointestinal Endoscopy has published a special issue for March on colorectal cancer. The issue includes a practical guide for approaching and managing serrated colon polyps, one of the most common types of polyps, and a study on reducing postpolypectomy bleeding with prophylactic clip closure. GIE: Gastrointestinal Endoscopy is the monthly peer-reviewed scientific journal of the American Society for Gastrointestinal Endoscopy (ASGE).
"The cutting edge of serrated polyps: a practical guide to approaching and managing serrated colon polyps"
Colonoscopy with detection and removal of colonic polyps is the foundation of colorectal cancer screening and surveillance programs. However, different types of colonic polyps have different malignant potential and recommendations for removal and follow-up surveillance varies depending on the type of polyp.
The most common colonic polyps include the conventional adenomas (tubular, tubulovillous, and villous adenomas which are precancerous polyps) and serrated polyps. Serrated polyps account for as many as 36 percent of colonic polyps. Initially the hyperplastic (benign) polyp was the only recognized serrated polyp. Today, the term serrated polyp is recognized as a general term describing a heterogeneous family of polyps with distinct molecular underpinnings, clinicopathologic features, and a varied capacity for malignant potential. In this review article from Christina A. Arnold, MD, Ohio State University, Columbus, and colleagues, the salient clinicopathologic features of serrated polyps and practical management recommendations are discussed.
The location and size of the serrated polyp are extremely helpful in determining the type of serrated polyp for the clinician and pathologist, therefore both should be documented. As conventional endoscopic techniques alone are unable to reliably diagnose polyps, histologic evaluation remains the criterion standard for accurate diagnosis. The most important type of serrated polyp is the sessile serrated adenoma/polyp (SSA/P). The prevalence of SSA/Ps ranges from one percent to nine percent of all colonic polyps. SSA/Ps are most commonly found in women, unlike the male-predominant conventional adenomas. Risk factors for SSA/Ps (and conventional adenomas) include older age, sex, smoking, and obesity; the latter two risk factors also independently predict large (>10 mm) SSA/Ps. Importantly, patients with SSA/Ps are more likely to have a greater polyp burden and synchronous and metachronous neoplastic lesions than patients without SSA/Ps. In addition, the progression from SSA/P with cytologic dysplasia to invasive carcinoma (cancer) may be relatively rapid. Complete removal of polyps, particularly small, flat, right-sided polyps (such as SSA/Ps) is challenging and associated with the development of interval carcinoma, likely through missing or incompletely removing the precursor lesion.
In September 2012, the U.S. Multi-Society Task Force on CRC (colorectal cancer) released updated guidelines for colonoscopy surveillance with a much-needed expansion on the management of serrated polyps. In addition to the U.S. Multi-Society Task Force guidelines, an expert consensus opinion was separately published in 2012 based on an expert panel discussion and review of advancements and insights in the serrated polyp literature. The 2012 guidelines have placed serrated polyps >10 mm or with cytologic dysplasia in the same surveillance category as high-risk adenomas with a three-year surveillance interval. The guidelines also advise a one-year surveillance interval for serrated polyposis (formerly "hyperplastic polyposis") a phenotypically variable condition associated with increased serrated polyps and an up to nearly 40 percent risk of colorectal cancer.
The expert consensus opinions recommend at least five-year endoscopic surveillance intervals for first-degree relatives of patients with serrated polyposis, starting at age 40 or 10 years younger than the age at diagnosis of the affected relative. Among the key management recommendations discussed in the guide for approaching and managing serrated colon polyps is the removal of serrated polyps. Given the malignant potential and that SSA/Ps are most often flat with indistinct borders, complete endoscopic resection (removal) is critical. When SSA/P margins cannot be fully resected, residual tissue can be removed by cold forceps or burned by argon plasma coagulation, and close endoscopic follow-up is advised at less than one year per the updated guidelines.
"Prophylactic clip closure reduced the risk of delayed postpolypectomy hemorrhage: experience in 277 clipped large sessile or flat colorectal lesions and 247 control lesions"