Volume 7 Supplement 2
Hereditary colorectal cancer and Lynch syndrome
© Rossi; licensee BioMed Central Ltd. 2013
Published: 4 April 2013
The term Hereditary Nonpolyposis Colorectal Cancer, or HNPCC, has been less used for naming the classical autosomal dominantly inherited susceptibility to cancer . As this susceptibility applies to tumors from different primary sites other than but including colorectal cancer (CRC), the term Lynch Syndrome (LS) is a less restrictive name. Lynch Syndrome is characterized by an autosomal dominantly inherited susceptibility to cancer, caused by inherited germline mutations in the mismatch repair (MMR) genes. It is characterized by early age of onset, predilection to the proximal colon, multiple primary CRCs, and extracolonic tumors, particularly endometrium carcinoma (EC) [2, 3].
To establish a profile of the disease, a better definition of the spectrum of related tumors has been a constant concern [4, 5]. It is therefore expected to find heterogeneity among the families regarding the susceptibility to develop tumors in different specific sites. The risk of cancer in fact varies among families with LS, although the variation does not necessarily result from genetic heterogeneity. The standards of environmental exposure must contribute to the differential gene expression, justifying at least in part this heterogeneity .
LS accounts for 2%–5% of all CRC cases . In fact, it is believed that 20% to 30% of patients with CRC present some type of genetic susceptibility, but without meeting criteria for known typical syndromes. However, new cancer cases in the patient’s family or supplemental information on previously unknown cases can lead to a reclassification that may characterize a typical syndrome. In other situations, despite the lack of clinical criteria for determining an inherited character, molecular inquiry can define the diagnosis of inherited syndrome. For these reasons, even in the absence of typical clinical characterization, criteria must be used to direct the inquiry of an inherited condition.
The spectrum of extracolonic tumors in LS began to be the subject of several publications in which the most common cancers found were those affecting the endometrium, the stomach and the urinary tract [8–14]. Watson and Lynch  calculated the frequency of cancer in other specific sites in 1,300 high-risk individuals from 23 families having LS and demonstrated a significant increase of the risk of developing cancer in the stomach (RR:4.1), small bowel (RR:25), kidneys (RR:3.2), ureter (RR:22), and ovary (RR:3.5). The proposed extracolonic cancers associated with LS are endometrium, stomach, ovary, small bowel, ureter, renal pelvis, brain, and hepatobiliary tract. Among these tumors, endometrium, ureter, renal pelvis, and small bowel cancers present the highest relative risk, and are therefore the most specific for LS.
The Amsterdam criteria for clinical diagnosis of LS are: (1) at least three relatives must have histologically verified CRC, endometrium, ureter, renal pelvis, or small bowel cancer; (2) one must be a first-degree relative of the other two; (3) at least two successive generations must be affected; (4) at least one of the relatives with cancer must have received the diagnosis before age 50; and (5) familial adenomatous polyposis must have been excluded. Because there are families with an MMR mutation present exclusively in patients with endometrial cancer without CRC, the requirement of at least one case of CRC was suppressed [15, 16].
Patients with LS may also have sebaceous adenomas, sebaceous carcinomas, and multiple keratoacanthomas, findings consonant with Torre’s syndrome variant [17, 18]. The definition of LS includes a familial clustering of colorectal and/or endometrial cancer and as associated cancers stomach, ovary, ureter/renal pelvis, brain, small bowel, hepatobiliary tract, and skin (sebaceous tumors) tumors [15, 19].
As discussed by Vasen , since it is known that LS is caused by an mismatch repair gene defect and that the hallmark of the syndrome is microsatellite instability (MSI), more attention should be given to the so-called Bethesda guidelines, which describe almost all clinical conditions in which there is suspicion of LS and in which a search for MSI is indicated, mainly early onset of colorectal adenomas and cancer.
- Jass JR: Hereditary non-polyposis CRC: the rise and fall of a confusing term. World J Gastroenterol. 2006, 12 (31): 4943-50.PubMed CentralPubMedGoogle Scholar
- Lynch HT, Watson P, Kriegler M, Lynch JF, Lanspa SJ, Marcus J, Smyrk T, Fitzgibbons RJ Jr, Cristofaro G: Differential diagnosis of hereditary nonpolyposis CRC (Lynch syndrome I and Lynch syndrome II). Dis Colon Rectum. 1988, 31 (5): 372-7. 10.1007/BF02564888.View ArticlePubMedGoogle Scholar
- Lynch HT, Watson P, Lanspa SJ, Marcus J, Smyrk T, Fitzgibbons RJ Jr, Kriegler M, Lynch JF: Natural history of CRC in hereditary nonpolyposis CRC (Lynch syndromes I and II). Dis Colon Rectum. 1988, 31 (6): 439-44. 10.1007/BF02552613.View ArticlePubMedGoogle Scholar
- Watson P, Lynch HT: The tumor spectrum in LS. Anticancer Res. 1994, 14: 1635-9.PubMedGoogle Scholar
- Aarnio M, Sankila R, Pukkala E, Salovaara R, Aaltonen LA, de la Chapelle A, Peltomäki P, Mecklin JP, Järvinen HJ: Cancer risk in mutation carriers of DNAmismatch- repair genes. Int J Cancer. 1999, 81: 214-8. 10.1002/(SICI)1097-0215(19990412)81:2<214::AID-IJC8>3.0.CO;2-L.View ArticlePubMedGoogle Scholar
- Watson P, Lynch HT: Extracolonic cancer in hereditary nonpolyposis CRC. Cancer. 1993, 71 (3): 677-85. 10.1002/1097-0142(19930201)71:3<677::AID-CNCR2820710305>3.0.CO;2-#.View ArticlePubMedGoogle Scholar
- Aarnio M, Mecklin JP, Aaltonen LA, Nystrom-Lahti M, Jarvinen HJ: Life-time risk of dif- ferent cancers in hereditary non-polyposis CRC (LS) syndrome. Int J Cancer. 1995, 64 (6): 430-3. 10.1002/ijc.2910640613.View ArticlePubMedGoogle Scholar
- Mecklin JP, Jarvinen HJ, Peltokallio P: Identification of cancer family syndrome. Gastroenterology. 1986, 90 (4): 1099-PubMedGoogle Scholar
- Mecklin JP, Jarvinen HJ: Clinical features of colorectal carcinoma in cancer family syndrome. Dis Colon Rectum. 1986, 29 (3): 160-4. 10.1007/BF02555012.View ArticlePubMedGoogle Scholar
- Ponz de Leon M, Sassatelli R, Sacchetti C, Zanghieri G, Scalmati A, Roncucci L: Familial aggregation of tumors in the three-year experience of a population-based CRC registry. Cancer Res. 1989, 49 (15): 4344-8.PubMedGoogle Scholar
- Fitzgibbons RJ, Lynch HT, Stanislav GV, Watson PA, Lanspa SJ, Marcus JN, Smyrk T, Kriegler MD, Lynch JF: Recognition and treatment of patients with hereditary nonpolyposis colon cancer (Lynch syndromes I and II). Ann Surg. 1987, 206 (3): 289-95. 10.1097/00000658-198709000-00007.PubMed CentralView ArticlePubMedGoogle Scholar
- Vasen HF, Offerhaus GJ, den Hartog Jager FC, Menko FH, Nagengast FM, Griffioen G, van Hogezand RB, Heintz AP: The tumour spectrum in hereditary non-polyposis CRC: a study of 24 kindreds in the Netherlands. Int J Cancer. 1990, 46 (1): 31-4. 10.1002/ijc.2910460108.View ArticlePubMedGoogle Scholar
- Mecklin JP, Jarvinen HJ: Tumor spectrum in cancer family syndrome (hereditary nonpolyposis CRC). Cancer. 1991, 68 (5): 1109-12. 10.1002/1097-0142(19910901)68:5<1109::AID-CNCR2820680535>3.0.CO;2-S.View ArticlePubMedGoogle Scholar
- Benatti P, Sassatelli R, Roncucci L, Pedroni M, Fante R, Di Gregorio C, Losi L, Gelmini R, Ponz de Leon M: Tumour spectrum in hereditary non-polyposis CRC (LS) and in families with “suspected LS”. A population-based study in northern Italy. Int J Cancer. 1993, CRC Study Group, 54 (3): 371-7. 10.1002/ijc.2910540304.Google Scholar
- Vasen HFA, Watson P, Mecklin JP, Lynch HT: New clinical criteria for hereditary nonpoly- posis CRC (LS, Lynch syndrome) proposed by the International Collaborative Group on LS. Gastroenterology. 1999, 116: 1453-6. 10.1016/S0016-5085(99)70510-X.View ArticlePubMedGoogle Scholar
- Vasen HF, Mecklin JP, Khan PM, Lynch HT: The International Collaborative Group on Hereditary Non-Polyposis CRC (ICG-LS). Dis Colon Rectum. 1991, 34 (5): 424-5. 10.1007/BF02053699.View ArticlePubMedGoogle Scholar
- Lynch HT, de la Chapelle A: Genetic susceptibility to non-polyposis CRC. J Med Genet. 1999, 36: 801-18.PubMed CentralPubMedGoogle Scholar
- Fusaro RM, Lemon SJ, Lynch HT: The Muir–Torre syndrome: a variant of the hereditary nonpolyposis CRC syndrome. J Tumor Marker Oncol. 1996, 11: 19-31.Google Scholar
- Lynch HT, de la Chapelle A: Hereditary CRC. N Engl J Med. 2003, 348 (10): 919-32. 10.1056/NEJMra012242.View ArticlePubMedGoogle Scholar
- Vasen HF: Clinical description of the Lynch syndrome [hereditary nonpolyposis CRC (LS)]. Fam Cancer. 2005, 4 (3): 219-25. 10.1007/s10689-004-3906-5.View ArticlePubMedGoogle Scholar
This article is published under license to BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.