Metachronous Serrated Neoplasia Is Uncommon After Right Colectomy in Patients with Methylator Colon Cancers With a High Degree of Microsatellite Instability

Abstract

Cancers with a high degree of microsatellite instability arise through 2 different molecular mechanisms. Metachronous serrated neoplasia, benign and malignant, following right colectomy in patients with the CpG-island methylator phenotype of colorectal cancer is uncommon. However, the colons of patients with Lynch syndrome are at high risk after segmental colectomy.

The Molecular Pathogenesis of Colorectal Cancer and Its Potential Application to Colorectal Cancer Screening

“…93, 100 This is also true of CIMP CRCs. 101 An important implication of these studies is that the genomic instability state of index polyps or CRC, the methylation state of individual genes in polyps, and CIMP may not be useful for developing personalized prevention programs for an individual since they appear to result from a stochastic process. However, this does not mean that these mechanisms cannot be targeted for prevention programs that can be applied to entire at-risk populations.…”

Serrated Polyps and Serrated Polyposis Syndrome

“…The development of metachronous left-sided colon cancer after right colectomy for a serrated pathway right-sided colon cancer is rare. 47 Patients must therefore be counseled regarding the risk for subsequent development of CRC, even when they are compliant with sequential and sometimes frequent exams. Of note, the use of minimally invasive approaches, including combined colonoscopic/laparoscopic approaches, have made surgical resection for polyps not amenable to colonoscopic resection a more patient-friendly option with less pain and quicker return to work.…”