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Cancer Risk in Serrated Polyposis Syndrome and Sporadic Sessile Serrated Lesion Patients and Their Relatives

Douglas K. Rex, MD, MASGE reviewing Kanth P, et al. Am J Gastroenterol 2021 Dec 10.

This study used the Utah Cancer Registry to examine cancer risk in patients with serrated polyposis syndrome (SPS) and their relatives as well as patients with sessile serrated lesions (SSLs) and their relatives. There were 59 patients with SPS, 754 patients with sporadic SSLs, and 1624 controls. 

The risk of colorectal cancer (CRC) in the patients with SPS was increased (relative risk [RR], 10.68) with all of those cancers being diagnosed at the initial colonoscopy. First-degree relatives (FDRs) of patients with SPS had an RR of 5.54 for CRC. Tumors were proximal in 40% of patients with SPS and 33% of their FDRs. The FDRs of patients with SPS had a more than 2-fold increased risk of any-site cancer, but the finding was suspect because the relatives had an older mean age than the patients (70 vs 59 years) and the patients themselves did not have an increased risk of extracolonic cancers. 

With regard to sporadic SSLs and the risk of CRC and extracolonic cancers in patients and their relatives, the results were inconclusive. One result indicated an increased risk of prostate cancer in patients with SSLs, and FDRs of these patients had increased CRC risk if the patient also had adenomas.


Important results from this study that have previously been identified include the finding that the risk of CRC in patients with SPS after initial clearing is low, suggesting we can expand surveillance intervals once the polyp burden is substantially reduced. Second, half or more of the cancers in patients with SPS and their relatives were in the left side of the colon, so detailed clearing of the left-sided colon is an important part of colonoscopy in patients with SPS and their relatives. Third, patients with SPS should be advised to inform their relatives of increased CRC risk and the need for colonoscopy. More data are needed to understand the risk of cancer in FDRs of patients with SSLs.
Note to readers: At the time we reviewed this paper, its publisher noted that it was not in final form and that subsequent changes might be made.

Douglas K. Rex, MD, MASGE

Bio and Disclosures


Kanth P, Yu Z, Keener MB, et al. Cancer risk in patients with and relatives of serrated polyposis syndrome and sporadic sessile serrated lesions. Am J Gastroenterol 2021 Dec 10. (Epub ahead of print) (