1. Kalyani Maganti, M.D

2. ASCO Chromosomes, DNA, and Genes Cell Nucleus Chromosomes Gene Protein

3. ASCO Disease-Associated Mutations A “mutation” is a change in the normal coding sequence of a gene that alters the function of the corresponding protein

4. ASCO Disease-Associated Mutations Alter Protein Function Functional protein Nonfunctional or missing protein

5. “All cancer arises from gene mutations”

6. ASCO Genes Associated With Cancer Predisposition Tumor suppressor genes Control rates of cell division and growth Control rates of cell division and growth Cancer arises when both gene copies are mutated Cancer arises when both gene copies are mutated DNA damage-repair genes Repair errors in DNA replication Repair errors in DNA replication Cancer arises when both genes fail, leading to the accumulation of mutations in other critical genes Cancer arises when both genes fail, leading to the accumulation of mutations in other critical genesOncogenes Accelerate cell division Accelerate cell division Cancer arises when stuck in “on” mode Cancer arises when stuck in “on” mode

8. Gene mutations – inherited or acquired? All cancer is caused by gene mutations Usually these mutations were not inherited, but were acquired over time in individual cells In ~10% of cancers the mutation is inherited – the person has a “hereditary predisposition” to cancer

9. ASCO Two normal genes (prevent cancer) 1st mutation (may be inherited (susceptible carrier), or acquired 2nd mutation or loss of gene function (leads to cancer) Gene mutations – inherited or acquired?

10. Hereditary cancer “syndromes” A mutation in a single gene increases cancer risk in multiple organs or parts of the body Increased risk is inherited, not cancer – so the individual may develop cancer in a single, multiple, or no parts of the body

11. Sporadic or Hereditary? ~75% of colon cancer is “sporadic” ~15-20% of colon cancer is “familial” ~5-8% of colon cancer is due to a single gene causing a “hereditary predisposition”

13. Characteristics of Hereditary Cancers Cancer diagnosed at an early age (before age 50) Close family members with same kind of cancer (or genetically related cancers, such as breast and ovarian) Bilateral cancer, or multiple primary cancers Unusual cancers (male breast cancer) Two kinds of cancer in the same person (syndrome)

14. Hereditary Cancer Syndromes Syndrome Hereditary breast and ovarian cancer Lynch syndrome Familial adenomatous polyposis Cowden syndrome Von Hippel-Lindau syndrome Li-Fraumeni syndrome Multiple Endocrine Neoplasia (1 or 2) Associated cancers Breast and Ovarian (etc.) Colon, Endometrial, ovarian, (etc.) Colon, duodenum (etc.) Breast, thyroid, endometrial (etc.) Renal cell, hemangioblastomas, (etc.) Sarcoma, breast, brain, adrenal, (etc.) Thyroid, parathyroid, other endocrine

15. 30 yrs 34 yrs Key: CRC Breast CA Cervical CA BrCa 85 yrs d.87 Colon Ca 54 yrs Cerv.Ca 30 yr 5558 Cerv.Ca 32 yr 60 d. 58 MI 84 56 CRC 79 d.82 Clues from the family history

16. ASCO 1st, 2nd-, and 3rd-Degree Relatives 2222 112 1 2 1 1 3 Child Brother Sister Father Mother Uncle First cousin Maternal grandmother Maternal grandfather Paternal grandmother Paternal grandfather Aunt

17. ASCO Dominant Inheritance l Each child has 50% chance of inheriting the mutation l No “skipped generations” l Equally transmitted by men and women Affected Normal

18. ASCO Recessive Inheritance l Two germ-line mutations (one from each parent) necessary to develop disease l Equally transmitted by men and women Noncarrier individual Non-affected carrier Affected individual

19. ASCO Genes aren’t the whole picture l “Penetrance” is often incomplete l May appear to “skip” generations l Individuals inherit altered cancer susceptibility gene, not cancer Normal Carrier, affected with cancer Susceptible Carrier Sporadic cancer

20. 30 yrs 34 yrs Key: CRC Breast CA Cervical CA BrCa 85 yrs d.87 Colon Ca 54 yrs Cerv.Ca 30 yr 5558 Cerv.Ca 32 yr 60 d. 58 MI 84 56 CRC 79 d.82 “ Familial” risk for colon cancer

21. Typical “hereditary” colon cancer family CRC dx 50s CRC dx 45 Gastric ca dx 52 CRC dx 61 + 63 CRC dx 75 Ovarian Ca, dx 64 CRC dx 48 CRC dx 50 Endometrial Ca, dx 59 CRC dx 42 + 55 45

22. “Familial” versus “single gene inheritance” of risk

23. Key: Endometrial CA Colorectal CA Adenomatous polyps Dx 38 Dx 50 88 yr 63 yr 4 polyps 50 yrs. CRC Dx 48 61 yr 38 yr 10 yr 8 yr 35 yr HNPCC: Colon cancer as part of a “syndrome”

24. HNPCC or “Hereditary Non-polyposis Colorectal Cancer syndrome” 3-5% of all colorectal cancer cases A cancer “syndrome” caused by a single gene mutation Cancers outside the colon: endometrium (uterus), ovary, stomach, urinary tract, small bowel, bile ducts, sebaceous glands

25. HNPCC: Clinical Diagnostic Criteria 3 or more relatives with an HNPCC-related cancer, one of whom is a 1 st degree relative of the other two 3 or more relatives with an HNPCC-related cancer, one of whom is a 1 st degree relative of the other two 2 or more generations affected 2 or more generations affected 1 or more cancers diagnosed before age 50 1 or more cancers diagnosed before age 50 Other syndromes excluded Other syndromes excluded ( Failure to meet these criteria does not exclude HNPCC )

28. Cancer Risks in HNPCC Aarnio M et al. Int J Cancer 64:430, 1995 % with cancer 100 80 60 40 20 0 204060800 Age (years) Colorectal 78% Endometrial 40-60% Stomach 13-19% Biliary tract 18% Urinary tract 10% Ovarian 9% 

29. The Family History Is Key to Diagnosing HNPCC CRC dx 50s CRCdx 45 Gastric ca dx 52 CRC dx 61+63 CRC dx 75 Ovarian Ca, dx 64 CRC dx 48 CRC dx 50 Endometrial Ca, dx 59 CRC dx 42+ 55 45

30. NCCN Surveillance and Prevention Guidelines for Lynch syndrome Colonoscopy at age 20-25, or 2-5 yrs prior to the earliest diagnosis; repeat every year Prophylactic hysterectomy and bilateral salpingo- oophorectomy is a risk reducing option for women who have completed childbearing Transvaginal U/S for ovarian and endometrial cancer may be considered at the clinicians’ discretion, but data do not support its efficacy Consider upper endoscopy for gastric and small bowel cancers, beginning at age 30-35 Consider annual urinalysis for urothelial cancer

31. ASCO The value of surveillance in HNPCC Percentage of individuals with an altered disease gene who develop the disease 020406080 0 20 40 60 80100 HNPCC mutation carriers General population Affected with colorectal cancer (%)

32. Screening for HNPCC Screening for HNPCC on basis of family history misses ~40% of cases Screening with combined family history and tumor testing detects ~100% of cases This combined approach to screening for HNPCC is recommended by current NCCN guidelines

33. Genetic Features of Lynch syndrome allow us to screen tumors – at the time of surgery (or years later) Four genes: can cause Lynch syndrome: (MLH1, MSH2, MSH6, PMS2) = “mismatch repair genes” Mutation in gene  absence of corresponding protein in tumor tissue  detected by IHC stains Mutation in gene  microsatellite instability in tumor DNA (caused by the loss of functional mismatch repair protein) These measurable differences in the tumor itself can be used to screen for Lynch syndrome and justify proceeding to genetic testing (of a blood sample)

34. Clues from the tumor – does this patient have a genetic mutation? Microsatellite instability (MSI) testing if MSI- unstable  high probability of a MMR mutation  proceed to genetic testing Immuno-histochemistry (IHC) for MMR proteins – are all four MMR proteins present? If no  proceed to genetic testing

35. Importance of the Pathology Report Colorectal cancer – polyp type and number indicates which syndrome to test for: Multiple adenomas  test APC gene – for FAP syndrome Few or no adenomas, proximal location of tumor  test for HNPCC syndrome (several genes) Hamartomas with freckling around mouth  test STK11 gene for Peutz-Jeghers syndrome with fam.hx. breast, thyroid, uterine cancer  test PTEN gene for Cowden syndrome

36. HNPCC 1 PROTOCOL PRE-SURGERY 7/08 Pre-Admit Nurse __ YES___NO Patient < 50 years old ___YES___NO Parent, sibling or child has a CANCER history of: colorectal, uterine, ovarian, stomach, bile duct, urinary tract, small bowel, pancreatic, brain or sweat gland cancer ___YES___NO Patient’s has a previous CANCER history of: colorectal, uterine, ovarian, stomach, bile duct, urinary tract, small bowel, pancreatic, brain or sweat gland cancer No to all Pre-op/Pre-Admit Nurse 1)Stamp pre-op form with HNPCC ALERT: Send Specimen for IHC 2)Notify OR scheduler – note on schedule made 3)Patient given information sheet on IHC 2 and MSI 3 testing Circulating Nurse 1)Obtain verbal order from Surgeon 2)Request for IHC testing filled out on pathology slip 3)Place specimen in formalin – follow specimen handling protocol Yes to Any Questions = Follow the Protocol All Colorectal and Uterine Cancer Patients Specimen to Pathology 1 – HNPCC=Hereditary Non-Polyposis Colorectal Cancer syndrome also called Lynch Syndrome 2 - IHC = immunohistochemistry 3 – MSI = microsatellite instability

38. Clinical Features of FAP (Familial adenomatosis polyposis) Early onset of colon polyps in teens or childhood Untreated polyposis leads to 100% risk of colon cancer

39. FAP is associated with : Malignant tumors: periampullary carcinoma gastric carcinoma thyroid tumors brain tumors (medulloblastoma) Non-malignant features: CHRPEs osteomas of the jaw(>90%) duodenal polyps (70%) epidermoid cysts (67%) desmoid tumors

43. ASCO MYH-associated Polyposis (MAP) l Multiple polyps (15-100) l Recessive inheritance l Two mutations (one from each parent) necessary to develop disease Noncarrier individual Non-affected carrier Affected individual

44. MYH gene - normally functions to repair mistakes in DNA (mistakes can lead to cancer) 1-2% of the population carries a single MYH mutation –> ~ 10,000 have two MYH mutations, and develop MYH-associated polyposis) Multiple colorectal adenomas (~15-100 polyps) – with onset in 30-50’s Progression of polyps to colon cancer usually by age 50

45. MYH-associated polyposis may be suspected if: Individual has multiple colon polyps (and possibly colon cancer), and no family history of polyposis or colon cancer Individual has multiple colon polyps (and possible colon cancer, and the only affected family members are siblings

47. Genetic Counseling for hereditary cancers Genetic counseling is an interactive process that allows people to: Address their concerns about hereditary risk for cancer Learn basic genetic principles Look at their personal and family history in the context of these genetic principles Learn if their perception of risk is realistic or not Learn about the process and the implications of genetic testing Find out what kinds of pro-active steps they could take to lower their cancer risks if they do carry a genetic mutation

48. Who should consider genetic counseling? (characteristics of hereditary cancers) Cancer diagnosed at an early age (before age 50) Close family members with same kind of cancer (or genetically related cancers, such as breast and ovarian) Bilateral cancer, or multiple primary cancers Ashkenazi Jewish ancestry and breast or ovary ca. Unusual cancers (male breast cancer) in the family Two kinds of cancer in the same person (syndrome)

49. 30 yrs 34 yrs Key: CRC Breast CA Cervical CA BrCa 85 yrs d.87 Colon Ca 54 yrs Cerv.Ca 30 yr 5558 Cerv.Ca 32 yr 60 d. 58 MI 84 56 CRC 79 d.82 Should everyone with a family history of colon cancer have genetic testing?

50. Using family history to screen for Lynch syndrome Key: Endometrial CA Colorectal CA Colon polyps Dx 38 Dx 50 88 yr 63 yr 4 polyps at 50 yrs. CRC Dx 48 61 yr 38 yr 10 yr 8 yr 35 yr Detects 60% Misses 40%

51. ASCO Ideally, Begin Testing With an Affected Person If a mutation is found in an affected person, testing will be more informative for other family members Colon Ca, 42 Colon Ca, 38 d.45 Colon Ca, 45 Person seeking counseling (proband) Test first, if possible

52. ASCO Interpreting a Negative Result No identified mutation in family Colon Ca, 52 Endometrial Ca, 47 Colon Ca, 45 37 MSH2 - Inconclusive Family with known mutation True negative Colon Ca, 52 Endometrial Ca, 47 Colon Ca, 45 MSH2 + 37 MSH2 -

53. Does this family have HNPCC ? CRC dx 50s CRCdx 45 Gastric ca dx 52 CRC dx 61+63 CRC dx 75 Ovarian Ca, dx 64 CRC dx 48 CRC dx 50 Endometrial Ca, dx 59 CRC dx 42+ 55 45

54. Genetic Counseling for hereditary cancers “Informed consent” for genetic testing includes discussing: the benefits and limitations of genetic testing what’s involved in the testing process possible results and their interpretation how one might respond to a positive test result (what are the emotional issues?) Risk management options for those found to carry a mutation (using the information in a pro-active way) Implications to other family members

55. Genetic testing for hereditary cancer syndromes Benefits 1. Genetic testing can identify individuals at high risk of developing specific cancers 2. Those at high risk have the opportunity to be pro-active in making medical and lifestyle choices to lower risk 3. Medical options include increased surveillance, chemoprevention, and/or prophylactic surgery 4. Patients who are not high risk can be spared anxiety and the need for increased surveillance Limitations 1. A negative result may not give any useful information 2. Some genetic variants are of unknown clinical significance

56. Kalyani Maganti, M.D