![]() Thisĭifference has since been replicated in numerous studies that have consistentlyįound that FDRs of affected cases are themselves at a twofold to (3.9%) among the first-degree relatives (FDRs) of patients who had died fromĬRC than among sex-matched and age-matched controls (1.2%). Utah families that reported a higher percentage of deaths from CRC Some of the earliest studies of family history of CRC were those of Interpretations of this observation are as follows: Places one at an increased risk of developing colon cancer. Research, however, does suggest a substantial risk of colon cancer in individuals with juvenile polyposis syndrome and Peutz-Jeghers syndrome, although the nonadenomatous polyps associated with these syndromes have historically been viewed as nonneoplastic.Įpidemiological studies have shown that a personal history of colon adenomas However, in certain circumstances, hamartomatous and juvenile polyps can progress into cancer. Polyps that have traditionally been considered nonneoplastic include those of the hyperplastic, juvenile, hamartomatous, inflammatory, and Transformation of any polyp into cancer goes through the adenoma-carcinoma sequence. In addition, most individuals with CRC diagnosed before age 50 years and without a family history of cancer do not have a pathogenic variant associated with an inherited cancer syndrome.Ĭolorectal cancer (CRC) is the third most commonly diagnosed cancer in both men and women.Įstimated new cases and deaths from CRC in 2023 in the United States:Ĭolorectal Polyps as Precursors to Colorectal Cancer (CRC)Ĭolorectal tumors present with a broad spectrum of neoplasms, ranging fromīenign growths to invasive cancer, and are predominantly epithelial-derived tumors (i.e., adenomas or adenocarcinomas). ![]() Many other families exhibit aggregation of CRC and/or adenomas, but with no apparent association with an identifiable hereditary syndrome, and are known collectively as familial CRC. ![]() The natural history of some of these syndromes is still being described. Serrated polyposis syndrome, which is characterized by the appearance of hyperplastic polyps, appears to have a familial component, but the genetic basis remains unknown. Many of these syndromes are also associated with extracolonic cancers and other manifestations. Other CRC syndromes and their associated genes include oligopolyposis ( POLE, POLD1), NTHL1, juvenile polyposis syndrome ( BMPR1A, SMAD4), Cowden syndrome ( PTEN), and Peutz-Jeghers syndrome ( STK11). Hereditary CRC has two well-described forms: (1) polyposis (including familial adenomatous polyposis and attenuated FAP, which are caused by pathogenic variants in the APC gene and MUTYH-associated polyposis, which is caused by pathogenic variants in the MUTYH gene) and (2) Lynch syndrome (often referred to as hereditary nonpolyposis colorectal cancer), which is caused by germline pathogenic variants in DNA MMR genes ( MLH1, MSH2, MSH6, and PMS2) and EPCAM. ![]()
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