Genetic Findings in Familial Gastrointestinal Cancers Zsofia K. Stadler, MD Clinical Genetics & GI Oncology Services Memorial Sloan-Kettering Cancer Center March 27, 2015

The heritable fraction of many human cancers is high:Sweden, Denmark, Finland registry of 44,788 twin pairs NEJM 343: 78-85, 2000

Hereditary GI Cancer Syndromes Colorectal cancer Lynch syndrome Polyposis syndromes FAP, AFAP, MAP, Newly implicated genes Gastric Cancer Hereditary Diffuse Gastric Cancer Syndromes associated with intestinal-type gastric cancer Pancreatic Cancer

Risk of Colorectal Cancer 15-40% 40%

Lynch Syndrome Associated extracolonic cancers Autosomal dominant Early onset colorectal cancer Multiple primaries Right colon predominance Associated extracolonic cancers Endometrium Ovary Stomach Urinary tract Small bowel Bile ducts Sebaceous skin tumors Brain

Lynch Syndrome Germline mutations in mismatch repair (MMR) genes: MLH1 MSH2 MSH6 PMS2 EPCAM

X DNA mismatch repair Microsatellite Instability Microsatellites: short, tandemly repeated DNA sequences Failure of DNA mismatch repair system leads to changes in length of a microsatellite allele due to deletions or insertions X SJ Sherer, Biochem. Soc. Trans. 2005

Identifying defective MMR IHC staining for MMR proteins Microsatellite instability analysis MLH1 present MLH1 absent -Use of marker mono- and dinucleotide DNA repeats to identify presence of MSI -High-MSI: ≥2/5 markers with instability -MLH1, PMS2, MSH2, MSH6 -Loss of expression of one or more proteins is indicative of dMMR Concordance between MSI-H and IHC is ~92-97%

Colon or Endometrial Cancer at age < 50** 2004 Bethesda Criteria* Colon or Endometrial Cancer at age < 50** **NCCN: All CRC regardless of age or CRC at age < 70 Two LS cancers in a single individual at any age Colon or Endometrial Cancer in an individual with one or more 1st degree relatives with a LS- cancer, with at least 1 diagnosed < 50 Colon or Endometrial cancer at any age, in an individual with 2 or more 1st or 2nd degree relatives with LS cancers *Modified to include Endometrial Cancer as defining diagnosis Umar et al. JNCI 2004 96:261

Cancer Risks in Lynch syndrome 100 80 Colorectal 60-80% % with cancer 60 Endometrial 40-60% 40 Stomach 4-13% 20 Ovarian 4-12% Urinary tract 2-12% Biliary tract 2% 20 40 60 80 Age (years) Adapted from Aarnio M et al. 1995, 1999

Pancreatic Cancer in Lynch Syndrome Age Cumulative Risk Population Families with MMR Gene Mutations 20 30 0.03% 40 0.01% 0.23% 50 0.04% 1.31% 60 0.18% 1.98% 70 0.52% 3.68% Patients with Lynch syndrome have an 8.6-fold increased risk of pancreatic cancer Kastrinos et al., JAMA 2009

“Sentinel Cancer” in Women with Lynch syndrome 117 women from 223 Lynch/HNPCC families with dual primary cancers In 13.6% endometrial and colorectal cancers diagnosed simultaneously In remaining 101 women: Lu KH, et al. Obstet Gynecol. 2005; 105:569-74

Colonoscopy Improves Survival in Lynch Syndrome Surveillance Survival No surveillance 100 92.2% 80 73.9% 60 40 5 10 15 Follow-up time (years) Jarvinen HJ et al. Gastroenterology. 2000; 118:829-34

Risk-Reduction Strategies in Lynch Syndrome Colorectal Colonoscopy every 1-2 years starting at 20-25 Chemoprevention options –ASA? Risk-reducing colectomy Gastric cancer Screening EGD, age 30-35 Endometrium / Ovary (Annual Endometrial Biopsy, starting at 30-35) (Transvaginal Ultrasound +/- CA125, 1-2 times per year, starting at 30-35) Risk-Reducing Hysterectomy with BSO Urinary Tract (only for patients at highest-risk (ie.: MSH2, male)?) Urinalysis every 1-2 years, starting at 25-35 Renal Ultrasound every 1-2 years, starting at 25-35

Emerging Data in Lynch Syndrome: Genotype-Phenotype Correlations Endometrial Cancer Risk Colorectal Cancer Risk Hendriks Y. et al., Gastroenterology, 2004; 127:17-25.

Emerging Data in Lynch Syndrome Genotype-phenotype correlations MLH1 mutation - higher risk of CRC MSH2 mutation - higher risk of extracolonic cancers (urothelial, sebaceous adenocarcinoma, ovary, etc) MSH6 mutation - higher risk of endometrial cancer PMS2- not enough data to date EPCAM – new gene, risks unknown Other possibly associated cancers Pancreas cancer Recent studies demonstrate possible increased risk of prostate and breast cancer Has NOT resulted in change in screening recommendations

Causes of Hereditary Susceptibility to CRC Sporadic (65 % – 85) Familial MYH, POLE, POLD1 (SNPs?) syndromes Lynch syndrome (HNPCC) (<0.1%) (3%) Familial adenomatous polyposis (FAP) (1%)

Familial Adenomatous Polyposis Essentially 100% penetrance with inevitable development of CRC if colon not removed Site Type of Cancer Lifetime Risk Small bowel (duodenum, periampulla) Duodenum, periampulla 4-12% Small bowel Distal to duodenum Rare Pancreas Adenocarcinoma ~2% Thyroid Papillary thyroid cancer 1-2% CNS Medulloblastoma <1% Liver Hepatoblastoma 1.6% Bile ducts

Management of FAP Start sigmoidoscopy/colonoscopy every 1-2 years by age 10-12 Prophylactic colectomy (Annual colonoscopy once polyps detected until colectomy) Surveillance for adenomas (rectum, rectal pouch) Endoscopic surveillance and prophylactic colectomy improves survival in at-risk patients UGI screening q1-3 years Thyroid? Hepatoblastoma?

Genotype-phenotype correlations M Nieuwenhuis , Crit Rev Onc Hem, 2007

MYH-associated colon cancer Attenuated FAP < 100 adenomas (ave. 30) Adenomas often R sided Older at presentation (ave. >50) UGI, thyroid risk similar to classic CHRPE, desmoids, Gardner’s rare Most often 5’, 3’ APC mutations MYH: base-excision repair gene First common recessive cancer syndrome Biallelic presents like FAP or AFAP Test if 10-15 or more adenomas, and APC negative 2 common mutations (Y165C, G382D), full sequencing ~2% population carrier rate Carrier state not yet fully understood

Mutations in polymerase proofreading linked to CRC/polyposis (Palles et al., Nat Genet. 2013) POLE Autosomal dominant Early-onset CRC, multiple or large adenomas with conventional pathology Tumors: MSS ?extracolonic tumors POLD1

Cancer Syndromes Associated with Gastric Cancer Susceptibility Implicated Gene(s) Other Associated Cancers Hereditary Diffuse Gastric Cancer CDH1 Lobular BC, CRC? Lynch syndrome MMR genes (MLH1, MSH2, MSH6, PMS2) CRC, endometrial, small intestine, ureter/renal pelvis, ovary, pancreas, biliary tract, skin, brain, etc. Li-Fraumeni syndrome p53 Sarcoma, leukemia, BC, brain cancer, ACC Peutz-Jeghers syndrome STK11 Pancreas, small bowel, gastroesophageal, CRC, BC, ovary etc. Familial adenomatous polyposis ? (ethnic/geographic variation?) APC CRC, Papillary thyroid, Medulloblastoma, Pancreatic (ampullary), Hepatoblastoma (child) Juvenile polyposis SMAD4, BMPR1A, ENG CRC, UGI tract, Pancreas

1964: Familial Gastric Cancer in a kindred of Maori ethnicity CDH1 encodes E-cadherin Guilford et al., Nature 1998; 392:402-405.

Updated IGCLC criteria for HDGC (2010) 2 cases of GC in 1st or 2nd degree relatives, one confirmed DGC diagnosed <50 3 confirmed DGC cases in 1st or 2nd degree relatives independent of age Age <40 at DGC diagnosis* Personal or family history of DGC and lobular breast cancer, one diagnosed <50* Fitzgerald et al., J Med Genet 2010; 47:436-444.

Risk of Diffuse Gastric Cancer Lifetime risk >80% Men 40%-67% by age 80 Women 63-83% by age 80 (Pharaoh et al., Gastroenterology 2001) Age at onset is highly variable Mean: age 40 (Range 14-85 years) New Zealand: Mean age 33 Lobular BC: Cumulative risk for CDH1 female mutation carriers is ~40% by age 80 Management: Prophylactic gastrectomy Role of endoscopy?

Rogers WM et al., Am J Surg Pathol 2008; Vol32 No.6.

Genetic Basis of Pancreatic Cancer (PC) Sporadic Hereditary Familial ~10% of PCs are hereditary/familial Familial Pancreatic Cancer PC in the setting of a known hereditary cancer predisposition syndrome Inherited factors may account for as much as 36% of PC cases (Lichenstein P et al., NEJM 2000)

Familial Pancreatic Cancer ≥ 2 first-degree relatives with pancreatic cancer without a known genetic defect ??

Hereditary Pancreatic Cancer Syndrome Genes Other Associated Cancers Hereditary Breast/Ovarian Cancer BRCA2, BRCA1 Breast, ovary, male breast Lynch syndrome MLH1, MSH2, MSH6, PMS2 Colon, endometrial, gastric, ovary, others Familial Atypical Multiple Mole Melanoma (FAMMM) CDKN2A , CDK4 Melanoma Peutz-Jeghers syndrome STK11 Colon, breast, stomach, ovary Hereditary Pancreatitis PRSS1 Others? PALB2, APC, ATM

Potential of next-generation sequencing technologies Mendelian Families (Linkage analysis) P53 APC Unlikely to exist (Common, large effect size) CDH1 BRCA1 BRCA2 MLH1 MSH2 PTEN STK11 Potential of next-generation sequencing technologies CDKN2A Phenotypic Effect Size MSH6 Candidate gene analysis PMS2 Low-penetrance High-penetrance ATM CYP1A1 CHEK2 APC (I1307K) BRIP1 PALB2 Hard to Identify (Rare variants with small effects) GWAS (Common, small effect size) BLM (BLMAsh ) JAK2** GSTM1 KITLG** 8q24 locus MSMB CHRNA3 CHRNA5 CHRNB4 TP63 TERT FGFR2 NUDT10 NUDT11 Very Rare Common Population Frequency

Multiplex testing for CRC susceptibility? Colon Cancer Genes Included in Commercially Available NGS Panels Ambry Genetics APC, BMPR1A, CDH1, CHEK2, EPCAM, MLH1, MSH2, MSH6, MUTYH, PMS2, PTEN, SMAD4, STK11, TP53 University of Washington APC, BMPR1A, CDH1, CHEK2, EPCAM, GALNT12, GREM1, MLH1, MSH2, MSH6, MUTYH, PMS2, PTEN, SMAD4, STK11, TP53 Mayo Medical Laboratories APC, AXIN2, BMPR1A, CDH1, CHEK2, EPCAM, GREM1, MLH1, MLH3, MSH2, MSH6, MUTYH, PMS2, PTEN, SMAD4, STK11, TP53

Limitations and Future Directions Barriers to genetic testing Lack of insurance reimbursement for the cost of genetic testing Advanced stage of disease at diagnosis Especially relevant in GI Oncology… Must improve awareness about inherited GI cancers Benefit for patient Benefit for family Increasing number of cancer susceptibility genes Emergence of multigene panels for specific cancer type Variants and incidental findings a real limitation at present Next-generation sequencing identifying novel syndromes, genes