Strategy for Hnpcc Testing

Law Of Attraction For Kids

Smart Parenting Guide

Get Instant Access

The ultimate goal of screening for HNPCC is to identify all cases of Lynch syndrome or other hereditary defects present in a population. In view of limited resources, identification of individuals who would benefit most from genetic testing is essential. To most efficiently identify germline mutations in patients identified through family history and clinical criteria to be at risk for HNPCC, a stepwise diagnostic procedure is recommended (Figure 19-4). The utility of this tiered approach has been demonstrated in studies that have successfully screened an unselected

Identify patients appropriate for testing using clinical criteria (see Table 24-1)

MSI and IHC analyses on tumor tissue from affected family member

MSI-H

MSI-L or MSS

Germline testing of MMR gene indicated by IHC analysis

Mutation screen and Southern blot

No alteration identified

Stop testing (does not rule out other hereditary causes of CRC)

Stop testing J

Mutation screen and Southern blot

No alteration identified

1

\r-H

Alteration identified

Polymorphism J-^^

i

Pathogenic mutation

\ Sequence change of undetermined significance

Test at-risk family members f Stop testing

Test at-risk family members

Figure 19-4. Flowchart for recommended HNPCC diagnostic procedure.

population with CRC to identify those who might benefit from genetic testing.16,17

Utilizing this approach, a combination of MSI and IHC analysis is first performed on tumor tissue as an initial screen for individuals at increased risk to have germline MMR defects. Since MSI is found in virtually all tumors derived from individuals with Lynch syndrome, it is generally unproductive to search for germline mutations in MMR genes in patients whose tumors do not demonstrate a mutator phenotype. Depending on the prior risk of the patient being tested, a large fraction of cases may not have evidence of defective MMR. This is especially the case for individuals that have a moderate risk for having HNPCC. Data from our Molecular Diagnostic Laboratory, which includes both moderate-risk (young age of onset only, one additional family member with CRC only, etc.) and high-risk (Amsterdam criteria) referral cases, has demonstrated that up to 70% of cases do not have evidence of defective MMR. Direct sequencing of several MMR genes in such cases would generally not be productive. The combination of MSI and IHC testing is a relatively inexpensive prescreen that can eliminate unnecessary and expensive germline testing when performed as the first step in a testing protocol.

If the tumor demonstrates an MSI-H phenotype, then IHC provides important information about the specific MMR gene that is most likely mutated. The subset of patients identified then would be considered for germline testing with appropriate genetic counseling. Germline testing of the appropriate MMR gene (identified by IHC) by mutation screening or direct sequencing in conjunction with Southern blot (or other assays capable of detecting germline deletions or other genomic rearrangements) would follow in those patients who provide informed consent. In this case, only the relevant gene is analyzed for a germline mutation, again minimizing the need to test several MMR genes. This approach is designed to be the most cost-effective and judicious use of resources at the present time. However, as technological advancements continue, this testing algorithm may be amended after further studies have proven the effectiveness of other approaches.

References

1. Lynch HT, Smyrk TC, Watson P, et al. Genetics, natural history, tumor spectrum, and pathology of hereditary nonpolyposis colorectal cancer: an updated review. Gastroenterology. 1993;104:1535-1549.

2. Lynch HT, Shaw MW, Magnuson CW, Larsen AL, Krush AJ. Hereditary factors in cancer. Study of two large midwestern kindreds. Arch Intern Med. 1966;117:206-212.

3. Lynch HT, Krush AJ. Cancer family "G" revisited: 1895-1970. Cancer. 1971;27:1505-1511.

4. Lynch HT, de la Chapelle A. Genetic susceptibility to non-polyposis colorectal cancer. J Med Genet. 1999;36:801-818.

5. Watson P, Lynch HT. The tumor spectrum in HNPCC. Anticancer Res. 1994;14:1635-1639.

6. Lynch HT, Fusaro RM, Roberts L, Voorhees GJ, Lynch JF. Muir-Torre syndrome in several members of a family with a variant of the Cancer Family Syndrome. Br J Dermatol. 1985;113:295-301.

7. Jass JR, Stewart SM. Evolution of hereditary non-polyposis colorectal cancer. Gut. 1992;33:783-786.

8. Jass JR. Colorectal adenoma progression and genetic change: is there a link? Ann Med. 1995;27:301-306.

9. Alexander J, Watanabe T, Wu TT, Rashid A, Li S, Hamilton SR. Histopathological identification of colon cancer with microsatellite instability. Am J Pathol. 2001;158:527-535.

10. Aarnio M, Mustonen H, Mecklin JP, Jarvinen HJ. Prognosis of col-orectal cancer varies in different high-risk conditions. Ann Med. 1998;30:75-80.

11. Frei JV. Hereditary nonpolyposis colorectal cancer (Lynch syndrome II). Diploid malignancies with prolonged survival. Cancer. 1992;69: 1108-1111.

12. Kouri M, Laasonen A, Mecklin JP, Jarvinen H, Franssila K, Pyrhonen S. Diploid predominance in hereditary nonpolyposis colorectal carcinoma evaluated by flow cytometry. Cancer. 1990;65:1825-1829.

13. Dolcetti R, Viel A, Doglioni C, et al. High prevalence of activated intraepithelial cytotoxic T lymphocytes and increased neoplastic cell apoptosis in colorectal carcinomas with microsatellite instability. Am J Pathol. 1999;154:1805-1813.

14. Gryfe R, Kim H, Hsieh ET, et al. Tumor microsatellite instability and clinical outcome in young patients with colorectal cancer. N Engl J Med. 2000;342:69-77.

15. Vasen HF, Mecklin JP, Khan PM, Lynch HT. The International Collaborative Group on Hereditary Non-Polyposis Colorectal Cancer (ICG-HNPCC). Dis Colon Rectum. 1991;34:424-425.

16. Aaltonen LA, Salovaara R, Kristo P, et al. Incidence of hereditary nonpolyposis colorectal cancer and the feasibility of molecular screening for the disease. N Engl J Med. 1998;338:1481-1487.

17. Cunningham JM, Cheong-Yong K, Christensen E, et al. The frequency of hereditary defective mismatch repair in a prospective series of unselected colorectal carcinomas. Am J Hum Genet. 2001;69:780-790.

18. Vasen HF, Watson P, Mecklin JP, Lynch HT. New clinical criteria for hereditary nonpolyposis colorectal cancer (HNPCC, Lynch syndrome) proposed by the International Collaborative group on HNPCC. Gastroenterology. 1999;116:1453-1456.

19. Boland CR, Thibodeau SN, Hamilton SR, et al. A National Cancer Institute workshop on microsatellite instability for cancer detection and familial predisposition: development of international criteria for the determination of microsatellite instability in colorectal cancer. Cancer Res. 1998;58:5248-5257.

20. Thibodeau SN, Bren G, Schaid D. Microsatellite instability in cancer of the proximal colon [comments]. Science. 1993;260:816-819.

21. Ionov Y, Peinado MA, Malkhosyan S, Shibata D, Perucho M. Ubiquitous somatic mutations in simple repeated sequences reveal a new mechanism for colonic carcinogenesis. Nature. 1993;363:558-561.

22. Aaltonen LA, Peltomaki P, Leach FS, et al. Clues to the pathogenesis of familial colorectal cancer. Science. 1993;260:812-816.

23. Lander ES, Linton LM, Birren B, et al. Initial sequencing and analysis of the human genome. Nature. 2001;409:860-921.

24. Strand M, Prolla TA, Liskay RM, Petes TD. Destabilization of tracts of simple repetitive DNA in yeast by mutations affecting DNA mismatch repair. Nature. 1993;365:274-276.

25. Peltomaki P,Aaltonen LA, Sistonen P, et al. Genetic mapping of a locus predisposing to human colorectal cancer. Science. 1993;260:810-812.

26. Fishel R, Lescoe MK, Rao MR, et al. The human mutator gene homolog MSH2 and its association with hereditary nonpolyposis colon cancer. Cell. 1993;75:1027-1038.

27. Leach FS, Nicolaides NC, Papadopoulos N, et al. Mutations of a mutS homolog in hereditary nonpolyposis colorectal cancer. Cell. 1993;75:1215-1225.

28. Fishel R, Kolodner RD. Identification of mismatch repair genes and their role in the development of cancer. Curr Opin Genet Dev. 1995;5:382-395.

29. Buermeyer AB, Deschenes SM, Baker SM, Liskay RM. Mammalian DNA mismatch repair. Annu Rev Genet. 1999;33:533-564.

30. Malkhosyan S, McCarty A, Sawai H, Perucho M. Differences in the spectrum of spontaneous mutations in the hprt gene between tumor cells of the microsatellite mutator phenotype. Mutat Res. 1996;316:249-259.

31. Ohzeki S, Tachibana A, Tatsumi K, Kato T. Spectra of spontaneous mutations at the hprt locus in colorectal carcinoma cell lines defective in mismatch repair. Carcinogenesis. 1997;18:1127-1133.

32. Bronner CE, Baker SM, Morrison PT, et al. Mutation in the DNA mismatch repair gene homologue hMLH1 is associated with hereditary non-polyposis colon cancer. Nature. 1994;368:258-261.

33. Papadopoulos N, Nicolaides NC, Wei YF, et al. Mutation of a mutL homolog in hereditary colon cancer. Science. 1994;263:1625-1629.

34. Miyaki M, Konishi M, Tanaka K, et al. Germline mutation of MSH6 as the cause of hereditary nonpolyposis colorectal cancer. Nat Genet. 1997;17:271-272.

35. Nicolaides NC, Papadopoulos N, Liu B, et al. Mutations of two PMS homologues in hereditary nonpolyposis colon cancer. Nature. 1994;371:75-80.

36. Wu Y, Berends MJ, Sijmons RH, et al. A role for MLH3 in hereditary nonpolyposis colorectal cancer. Nat Genet. 2001;29:137-138.

37. Akiyama Y, Sato H, Yamada T, et al. Germ-line mutation of the hMSH6/GTBP gene in an atypical hereditary nonpolyposis colorec-tal cancer kindred. Cancer Res. 1997;57:3920-3923.

38. Wijnen J, de Leeuw W, Vasen H, et al. Familial endometrial cancer in female carriers of MSH6 germline mutations. Nat Genet. 1999;23:142-144.

39. Wu Y, Berends MJ, Mensink RG, et al. Association of hereditary nonpolyposis colorectal cancer-related tumors displaying low microsatellite instability with MSH6 germline mutations. Am J Hum Genet. 1999;65:1291-1298.

40. Beck NE, Tomlinson IP, Homfray T, et al. Use of SSCP analysis to identify germline mutations in HNPCC families fulfilling the Amsterdam criteria. Hum Genet. 1997;99:219-224.

41. Wagner A, Barrows A, Wijnen JT, et al. Molecular analysis of hereditary nonpolyposis colorectal cancer in the United States: high mutation detection rate among clinically selected families and characterization of an American founder genomic deletion of the MSH2 gene. Am J Hum Genet. 2003;72:1088-1100.

42. Lindor NM, Rabe MS, Peterson GM, et al. Lower cancer incidence in Amsterdam-I criteria families without mismatch repair deficiency. JAMA. 2005;293:1979-1985.

43. Lynch HT, Smyrk T, Lynch J. An update of HNPCC (Lynch syndrome). Cancer Genet Cytogenet. 1997;93:84-99.

44. Nystrom-Lahti M, Wu Y, Moisio AL, et al. DNA mismatch repair gene mutations in 55 kindreds with verified or putative hereditary non-polyposis colorectal cancer. Hum Mol Genet. 1996;5:763-769.

45. Lewis CM, Neuhausen SL, Daley D, et al. Genetic heterogeneity and unmapped genes for colorectal cancer. Cancer Res. 1996;56:1382-1388.

46. Huang J, Kuismanen SA, Liu T, et al. MSH6 and MSH3 are rarely involved in genetic predisposition to nonpolypotic colon cancer. Cancer Res. 2001;61:1619-1623.

47. Baudhuin LM, Burgart LJ, Leontovich O, et al. Use of microsatellite instability and immunohistochemistry testing for the identification of individuals at risk for Lynch syndrome. Familial Cancer. 2005;4: 255-265.

48. Bhattacharyya NP, Skandalis A, Ganesh A, Groden J, Meuth M. Mutator phenotypes in human colorectal carcinoma cell lines. Proc Natl Acad Sci U S A. 1994;91:6319-6323.

49. Thibodeau SN, French AJ, Cunningham JM, et al. Microsatellite instability in colorectal cancer: different mutator phenotypes and the principal involvement of hMLH1. Cancer Res. 1998;58:1713-1718.

50. Zhou XP, Hoang JM, Li YJ, et al. Determination of the replication error phenotype in human tumors without the requirement for matching normal DNA by analysis of mononucleotide repeat microsatellites. Genes Chromosomes Cancer. 1998;21:101-107.

51. Umar A, Boland CR, Terdiman JP, et al. Revised Bethesda guidelines for hereditary nonpolyposis colorectal cancer (Lynch syndrome) and microsatellite instability. J Nat Cancer Inst. 2004;96:261-267.

52. Pastrello C, Baglioni S, Tibiletti MG, Papi L, Fornasarig M, Morabito A, Agostini M, Genuardi M, Viel A: Stability of BAT26 in tumours of hereditary nonpolyposis colorectal cancer patients with MSH2 intragenic deletion, Eur J Hum Genet. 2006,14:63-68.

53. Konishi M, Kikuchi-Yanoshita R, Tanaka K, et al. Molecular nature of colon tumors in hereditary nonpolyposis colon cancer, familial polyposis, and sporadic colon cancer. Gastroenterology. 1996;111: 307-317.

54. Jass JR, Biden KG, Cummings MC, et al. Characterisation of a subtype of colorectal cancer combining features of the suppressor and mild mutator pathways. J Clin Pathol. 1999;52:455-460.

55. Cunningham JM, Boardman LA, Burgart LJ, Thibodeau SN. Microsatellite instability in colon cancers. In: Wells R, Warren S, eds. Genetic Instabilities and Hereditary Neurological Diseases. Academic Press, San Diego, CA; 1998:791-807.

56. Kane MF, Loda M, Gaida GM, et al. Methylation of the hMLH1 promoter correlates with lack of expression of hMLH1 in sporadic colon tumors and mismatch repair-defective human tumor cell lines. Cancer Res. 1997;57:808-811.

57. Cunningham JM, Christensen ER, Tester DJ, et al. Hypermethylation of the hMLH1 promoter in colon cancer with microsatellite instability. Cancer Res. 1998;58:3455-3460.

58. Dietmaier W, Wallinger S, Bocker T, Kullmann F, Fishel R, Ruschoff J. Diagnostic microsatellite instability: definition and correlation with mismatch repair protein expression. Cancer Res. 1997;57:4749-4756.

59. Thibodeau SN, French AJ, Roche PC, et al. Altered expression of hMSH2 and hMLH1 in tumors with microsatellite instability and genetic alterations in mismatch repair genes. Cancer Res. 1996;56: 4836-4840.

60. Ganguly A, Rock MJ, Prockop DJ. Conformation-sensitive gel electrophoresis for rapid detection of single-base differences in double-stranded PCR products and DNA fragments: evidence for solvent-induced bends in DNA heteroduplexes [published erratum appears in Proc Natl Acad Sci U S A. 1994;91:5217]. Proc Natl Acad Sci U S A. 1993;90:10325-10329.

61. Orita M, Iwahana H, Kanazawa H, Hayashi K, Sekiya T. Detection of polymorphisms of human DNA by gel electrophoresis as singlestrand conformation polymorphisms. Proc Natl Acad Sci U S A. 1989;86:2766-2770.

62. Lerman LS, Silverstein K, Grinfeld E. Searching for gene defects by denaturing gradient gel electrophoresis. Cold Spring Harb Symp Quant Biol. 1986;51:285-297.

63. Underhill PA, Jin L, Lin AA, et al. Detection of numerous Y chromosome biallelic polymorphisms by denaturing high-performance liquid chromatography. Genome Res. 1997;7:996-1005.

64. Powell SM, Petersen GM, Krush AJ, et al. Molecular diagnosis of familial adenomatous polyposis. N Engl J Med. 1993;329:1982-1987.

65. Frischmeyer PA, Dietz HC. Nonsense-mediated mRNA decay in health and disease. Hum Mol Genet. 1999;8:1893-1900.

66. Wijnen J, van der Klift H, Vasen H, et al. MSH2 genomic deletions are a frequent cause of HNPCC. Nat Genet. 1998;20:326-328.

67. Wang Y, Friedl W, Lamberti C, et al. Hereditary nonpolyposis colorectal cancer: frequent occurrence of large genomic deletions in MSH2 and MLH1 genes. Int J Cancer. 2003;103:636-641.

68. Baudhuin LM, Mai M, French AJ, et al. Analysis of hMLH1 and hMSH2 gene dosage alterations in hererditary nonpolyposis col-orectal cancer patients by novel methods. J Mol Diagn. 2005;7:26-235.

69. Gille JJ, Hogervorst FB, Pals G, et al. Genomic deletions of MSH2 and MLH1 in colorectal cancer families detected by a novel mutation detection approach. Br J Cancer. 2002;87:892-897.

70. Yan H, Papadopoulos N, Marra G, et al. Conversion of diploidy to haploidy. Nature. 2000;403:723-724.

Was this article helpful?

0 0
Joy Of Modern Parenting Collection

Joy Of Modern Parenting Collection

This is a collection of parenting guides. Within this collection you will find the following titles: Issues, rule and discipline, self esteem and tips plus more.

Get My Free Ebook


Post a comment