title: Extracolonic cancer risk in patients with serrated polyposis syndrome and their first-degree relatives.
abstract: Serrated polyposis syndrome is associated with an increased colorectal cancer risk. Although the underlying genetic cause of the condition is unknown, first-degree relatives of patients with serrated polyposis have an increased risk for colorectal cancer compared with the general population. This suggests an inheritable component. Since other hereditary polyposis syndromes are often associated with an expanded extracolonic tumour spectrum, our aim was to determine the extra colonic cancer risks for patients with serrated polyposis and their first-degree relatives and compare these risks with the general population. Serrated polyposis index patients from 5 medical centres were included. Demographic data concerning age, sex and reported malignancies were ascertained by reviewing medical charts and histopathology reports. Family history was obtained by examining pedigree records from the department of Clinical Genetics. Incidence rates of extracolonic malignancies were compared with the general population through a person-year analysis, adjusted for age and sex. Population-based incidence data were derived from the Eindhoven Cancer Registry. A total of 105 patients with serrated polyposis and 341 first-degree relatives were included. Among the patients with serrated polyposis, 9 extracolonic cancers were observed, compared to 13 expected malignancies in the general population (RR 0.69 95% CI 0.36-1.33; p = 0.27). Among the first-degree relatives, 44 extracolonic malignancies were observed, compared to 48 expected malignancies (RR 0.92 95% CI 0.69-1.24; p = 0.60). In this study, the overall incidence of extracolonic malignancies in patients with serrated polyposis and their first-degree relatives was not increased. Large international studies are required to confirm these results.
authors.affiliation: Department of Gastroenterology and Hepatology, Academic Medical Centre, Meibergdreef 9, 1105 AZ, Amsterdam, The Netherlands, y.hazewinkel@amc.nl.
authors.forename: Yark
authors.initials: Y
authors.lastname: Hazewinkel
authors.forename: Johannes B
authors.initials: JB
authors.lastname: Reitsma
authors.forename: Fokko M
authors.initials: FM
authors.lastname: Nagengast
authors.forename: Hans F
authors.initials: HF
authors.lastname: Vasen
authors.forename: Theo A M
authors.initials: TA
authors.lastname: van Os
authors.forename: Monique E
authors.initials: ME
authors.lastname: van Leerdam
authors.forename: Jan-Jacob
authors.initials: JJ
authors.lastname: Koornstra
authors.forename: Evelien
authors.initials: E
authors.lastname: Dekker
mesh_terms: D000368:Aged; D003111:Colonic Polyps / Q000150:complications* / Q000473:pathology; D015179:Colorectal Neoplasms / Q000150:complications* / Q000473:pathology; D005190:Family; D005260:Female; D005500:Follow-Up Studies; D020022:Genetic Predisposition to Disease; D006801:Humans; D008297:Male; D008875:Middle Aged; D009369:Neoplasms / Q000209:etiology* / Q000473:pathology; D011230:Precancerous Conditions / Q000150:complications* / Q000473:pathology; D011379:Prognosis; D013577:Syndrome