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Abstract

Thank you to Dr Matuchansky for the excellent editorial response letter. I appreciate the additional references that Dr Matuchansky has provided in regards to the large population-based study of familial colorectal cancer (CRC) risk in Denmark.1Carstensen B. et al.Int J Cancer. 1996; 68: 428-435Google Scholar Indeed, this study showed a significantly higher risk of CRC in siblings compared with other first-degree relative (FDR) types (ie, parents). Because all of the quoted studies2Graaf R.E. et al.Clin Gastroenterol Hepatol. 2017; 15: 1256-1264Abstract Full Text Full Text PDF Scopus (51) Google Scholar, 3Samadder N.J. et al.Clin Gastroenterol Hepatol. 2015; 13: 2305-2311Abstract Full Text Full Text PDF Scopus (33) Google Scholar, 4Fuchs C. et al.N Engl J Med. 1994; 331: 1669-1674Google Scholar showed a markedly increased risk of CRC for all classes of FDRs, although the absolute estimates differed as to whether one group (parents vs siblings vs children) had a higher risk than the other, it is prudent for clinicians to counsel all FDRs about the increased CRC risk, with particular attention to siblings, advising an earlier age of initiation and a shorter surveillance interval for colonoscopy. Risk of Colorectal Carcinoma in Siblings of Probands With Common Colorectal CarcinomaClinical Gastroenterology and HepatologyVol. 16Issue 2PreviewI read with great interest the article by Graaf et al,1 and the accompanying editorial by Sammader et al,2 about the familial risk and heritability of colorectal cancer (CRC) in the Nordic Twin Study of Cancer. Graaf et al1 clearly showed that twins, especially monozygotic twins, of affected co-twins were at substantially increased risk of CRC relative to the general population and should consider personalized screening.1 In their discussion, they rightly suggested that siblings, who are as genetically similar as dizygotic twins, of affected individuals should be encouraged to undergo routine CRC screening, but they did not quote references specifically concerning nontwin siblings to support their suggestion. Full-Text PDF