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LYNCH SYNDROME:

HEREDITARY CANCER, PAST

AND PRESENT

HENRY T. LYNCH, MD

Creighton University

School of Medicine

Omaha, Nebraska

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Advancing Personalized/Precision

Cancer Medicine*

Why pursue molecular genetics?:

1. Genetic changes used to guide individual tx;

2. Sequencing technologies and DNA isolation

methods;

3. Multiplex hotspot mutation testing at the point of

care.**

*Cescon & Bedard. J Clin Oncol 33:1318-1321, 2015.

**Wagle et al. Cancer Discov 2:82-93, 2012

Majewski et al. J Clin Oncol 33:1334-1339, 2015.

Pogue-Geile et al. J Clin Oncol 33:1340-1347, 2015.

Advancing Personalized/Precision

Cancer Medicine*

Clinical example:

PIK3CA most commonly mutated oncogene in breast

cancer, present in ~25% of HER2-positive tumors*;

Majewski et al.** demonstrated that PIK3CA is

actionable as a predictive biomarker for HER2-

targeted therapies and could have major clinical

consequences.

*Cescon & Bedard. J Clin Oncol 33:1318-1321, 2015.

**J Clin Oncol 33:1334-1339, 2015.

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Aldred Scott Warthin, M.D., Ph.D.

(1866-1931)

A Renaissance Man -- physician, musician, teacher,

writer, editor and, above all, a remarkably creative

physician-scientist.

Graduated from Cincinnati Conservatory of Music at

age 21.

Then became an assistant in internal medicine and

published a paper entitled, “Accentuation of the

Pulmonary Second Sound: An Important Sign in the

Diagnosis of Pericarditis,” which was later named

“Warthin’s Sign”.

Aldred Scott Warthin, M.D., Ph.D.

(1866-1931)

The history of LS begins in 1895 with

Warthin’s concern about cancer in his

seamstress’s family.

He queried her and developed the

pedigree.

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Archives of Internal Medicine Vol. 12, July-Dec., 1913

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Archives of Internal Medicine

Vol. 12, July-Dec., 1913

History of Lynch Syndrome

In 1962, Lynch identified a patient with a

strikingly similar history.

Depressed, alcoholic with DTs, all

reportedly because of his fear of cancer.

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Science 260:810-812, 1993.

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Molecular Classification of CRC

Classification broadly divided into 2 general groups*:

1) genomic differences: chromosomal instability,

accounting for 75-80% of all CRCs;

2) microsatellite instability (MSI) accounting for 15-

20% of all CRCs.

*Markowitz & Bertagnolli. N Engl J Med 361:2449-2460, 2009.

Al-Sohaily et al. J Gastroenterol Hepatol 27:1423-1431, 2012.

14 Hereditary Cancer Syndromes:

Nuts and Bolts

• Family history;

• Hereditary cancer syndrome diagnosis;

• Genetic counseling;

• DNA studies;

• Highly targeted surveillance/management;

• Extend to all at-risk relatives;

• Physician education;

• Research problem of discrimination (insurance,

employment);

• Strategies for wide-spread interest of familial

cancer approach to cancer control, malpractice,

molecular genetics, other.

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Familial/Hereditary CRC in US

Annual CRC incidence in US: 142,820

Lynch syndrome 3-5% of all CRC 4,285 - 7,141

FAP <1% of all CRC <1,428

Familial 20% of all CRC 28,564

Siegel et al. CA Cancer 63:11-30, 2013.

Family History:

• Must be comprehensive;

• 3-4 generations with both maternal and paternal

lineages (see modified nuclear pedigree);

• Cancer of all anatomic sites;

• Verification whenever possible.

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Hereditary Cancer Syndromes

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Why Pursue Cancer of All Anatomic Sites?

Pertinent for any hereditary cancer syndrome diagnosis;

Most identified by pattern of cancer expression, e.g.:

• breast and ovary (HBOC syndrome);

• CRC, endometrium, ovary, others (Lynch syndrome);

• sarcomas, breast, brain, multiple others in SBLA (Li-

Fraumeni syndrome);

• medullary thyroid carcinoma and

pheochromocytoma (MEN-2a and MEN-2b);

• melanoma and pancreatic cancer with CDKN2A

(p16) mutation (FAMMM syndrome);

• diffuse gastric cancer and lobular breast cancer

with CDH1 mutation (HDGC syndrome);

• multiple colonic polyps in FAP and several additional

hereditary polyposis syndromes;

...and the list goes on.

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Patient’s Modified Nuclear Pedigree

Lynch et al. Nat Rev Cancer 15:181-194, 2015.

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Family History (FH)

FH is the linchpin in this effort.

Often ignored or insufficiently recorded – compromising opportunity for targeting patients for DNA testing.

Could enable more certainty for its targeted clinical translation, surveillance, and personalized medical management.*

*Guttmacher et al. N Engl J Med 351:2333-2336, 2004.

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Could this be

hereditary

Colon Cancer

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Sporadic

Familial Hereditary

FAP; AFAP

Mixed Polyposis Syndrome

Ashkenazi I1307K

CHEK2 (HBCC)

MUTYH (MAP)

TGFBR1

PJS

FJP

CD

BRRS

Hamartomatous

Polyposis

Syndromes

AC-1 without MMR

(Familial CRC of

syndrome “X”)

TACSTD1 (EPCAM)

= as yet undiscovered

hereditary cancer variants

Constitutional mosaic

epimutation (MLH1)

Syndrome Gene CRC Risk Average age of dx

Sporadic cancer 4.8% 69

Lynch syndrome MLH1/MSH2 M: 27-74%

F: 22-61%

27-60

MSH6 M: 22-69%

F: 10-30%

M/F: 12%

50-63

PMS2 M: 20%

F: 15%

47-66

FAP APC 100% 38-41

Attenuated FAP APC 69% 54-58

MUTYH-associated MUTYH 43-100% 48-50

Juvenile polyposis SMAD4/BMPR1A 38-68% 34-44

Peutz-Jeghers STK11 39% 42-46

Cowden syndrome PTEN 9-16% 44-48

Serrated polyposis Not known ~>50% 48

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Syngal et al. Am J Gastroenterol 110:223-262, 2015.

Differential Diagnosis – Lynch Syndrome

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Cardinal Features of Lynch Syndrome

• Family pedigree shows autosomal dominant inheritance pattern for syndrome cancers.

• Proximal (right-sided) CRC predilection: 70-85% of Lynch syndrome CRCs are proximal to the splenic flexure.

• Earlier average age of CRC onset than in the general population:

- Lynch syndrome: 45 years;

- general population: 63 years.

• Accelerated carcinogenesis, i.e., shorter time for a tiny adenoma to develop into a carcinoma:

- Lynch syndrome: 2-3 years;

- general population: 8-10 years.

• High risk of additional CRCs:

25-30% of patients who have surgery for a LS-associated CRC will

have a second primary CRC within 10 years, if surgery was < a

subtotal colectomy.

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Increased risk for certain

extracolonic malignancies Endometrial

Ovary

Stomach

Small bowel

Pancreas

Liver and biliary tree

Muir-Torre cutaneous features

Brain, (glioblastoma) – Torre syndrome features

Prostate cancer

Breast

Adrenal cortical carcinoma and others.

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Pathology of Lynch Syndrome

• Differentiating pathology features of LS CRCs:

- more often poorly differentiated;

- excess of mucoid and signet-cell features;

- Crohn’s-like reaction;

- significant excess of infiltrating lymphocytes

within the tumor.

• Increased survival from CRC.

• Sine qua non for diagnosis is identification of

germline mutation in MMR gene (most commonly

MLH1, MSH2, MSH6) segregating in the family.

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Problem Areas

• Dx of Hereditary Cancer frequently

missed.

• Classification encumbered by phenotypic/genotypic

heterogeneity.

• Labor Intensive: MD time limited; poor

reimbursement.

• Paucity of patient/MD interest and/or knowledge.

• Germline mutation, i.e., BRCA1/BRCA2, p53,

MMR mutations (MLH, MSH2, MSH6, PMS2) very

expensive.

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Should we test all

colorectal cancer for

Lynch Syndrome?

YES! Test everybody.

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Search for LS Among CRC Affecteds*

Evidence:

Among 500 CRC patients, 18 (3.6%) had LS.

Of these 18:

18 (100%) had MSI-H CRCs;

17 (94%) were correctly predicted by IHC;

only 8 (44%) were dx < 50 years;

only 13 (72%) met the revised Bethesda guidelines;

1/35 cases of CRC show LS.

*Hampel et al. J Clin Oncol 26:5783-5788, 2008.

Evidence of Cost-Effectiveness in LS*

Widespread CRC testing identifies LS;

Yields substantial benefits at acceptable cost;

Enables ♀ with an LS mutation to begin regular

screening, have risk-reducing prophylactic gyn

surg;

Cost-effectiveness depends on participation rate

among relatives at risk for LS.

*Ladabaum et al. Ann Intern Med 155:69-79, 2011.

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MSI Pathway

Technical Aspects of Testing*:

dMMR detected by immunohistochemistry (IHC) and

MSI by polymerase chain reaction (PCR).

Tumor classified as:

• MSI-high if 2 of 5 MSI markers show instability;

• MSI-low if only 1 of 5 markers is unstable;

• MSS if MSI markers show no expansion.

*Zhang & Li. World J Gastrointest Oncol 5:12-19, 2013.

Laghi et al. Oncogene 27:6313-6321, 2008.

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Genetic Heterogeneity in Lynch Syndrome

Lynch Syndrome is associated with germline mutations in any one of at least five genes

Chr 2

Chr 3

Chr 7

MSH2

PMS1

MLH1

PMS2

MSH6

Mismatch Repair (MMR) Mutations

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BRAF V600E mutation and LS

BRAF V600E mutation can sort this out

since when detected it excludes LS and

contributes to improved cost-

effectiveness of genetic testing for LS.

*Clin Gastroenterol Hepatol 6:206-214, 2008.

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MORPHOLOGY

SUSPICIOUS

FOR MSI-H

Run PCR test

for MSI status

Is there

MSI-H?

Run mutation analysis

for BRAF V600E

Is there

BRAF V600E

mutation?

SPORADIC CRC

WITH MSI-H

NO EVIDENCE OF

LYNCH

SYNDROME

Is there loss

of staining

with any of

the Abs?

IHC for MLH1,

MSH2, MSH6, PMS2

PUTATIVE

LYNCH

SYNDROME

MMR GENES MUTATION

ANALYSIS

Is there

a mutation in MMR

gene?

LYNCH

SYNDROME

YES

YES

NO

NO

NO

YES

YES

NO

Gatalica Z, Torlakovic E. Fam Cancer 2008;7:15-26

FAMILIAL CRC

TYPE “X”

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Patients with Deficient MMR Tumors

Such patients have distinct clinicopathologic

characteristics and have been associated with a

better stage-adjusted prognosis as compared with

those with proficient MMR tumors.

Microsatellite instability (MSI) is a molecular marker

of defective DNA mismatch repair (MMR).

Constitutes an important oncogenic molecular

pathway in CRC.

Present in ~15% of all CRC.

Patients with Deficient MMR Tumors

MMR deficiency may predict tumor chemoresistance

to 5FU adjuvant tx, especially in patients with

somatic hypermethylation of MLH1 promotor but

possibly not in those with germline MMR mutations.

Preliminary data suggest that adding oxaliplatin to

5FU could restore benefit of adjuvant chemotherapy

in MSI patients.

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Survival

Patients with dMMR/MSI tumors are less likely to

have lymph node and distant metastatic disease

than patients with MMR-proficient (pMMR) tumors.

The prevalence of the dMMR/MSI phenotype

decreases with advancing stage at dx from >20%

in stage II to <4% in stage IV.

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Survival

(continued):

In the aggregate, the hypothesis is that dMMR/MSI

tumors have reduced metastatic potential and that

favorable biology compared with pMMR/MSS

tumors is supported.

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T. Smyrk, MD (Mayo, Rochester, MN)

Tumor infiltrating lymphocytes

Cancer 91:2417 – 2422, 2001.

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Epigenetics and Lynch Syndrome*

No pathogenic mutation identified in ~ one-third of

LS.

Now we have an alternative mechanisms of

constitutional epimutation of 2 major MMR genes,

MLH1 and MSH2.

*Megan P. Hitchins, Ph.D., The Role of Epigenetics in

Lynch Syndrome. Fam Cancer 12:189-205, 2013

Epigenetics and Lynch Syndrome*

Gene expression changes include methylation of

cytosine bases within cytosine-guanine (CpG)

dinucleotides, modifications of the histone core of

nucleosomes and positioning of nucleosomes along

the DNA sequence.

We now have irrefutable evidence of the etiologic

role of epimutations of MLH1 and MSH2 in LS.

*Megan P. Hitchins, Ph.D., The Role of Epigenetics

in Lynch Syndrome. Fam Cancer 12:189-205, 2013

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Polyadenylation Sequence

5’ EPCAM deletion

Exons 8 and 9 and polyadenylation sequence

Ligtenberg MJ, Nature Genetics 2009.

Transcriptional read through Hypermethylation of the MSH2 promoter

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Why LS with Site-Specific CRC?

Deletion in EPCAM results in hypermethylation

and incomplete silencing of MSH2.

EPCAM mutation carriers may have phenotypic

features that differ from carriers of MSH2

mutations – namely, an almost exclusive

expression of site-specific CRC, thereby lacking

extracolonic cancers.

Endometrial (EC) and Ovarian Cancer

Screening

Effectiveness of screening for EC and/or Ovarian

cancer is unproven;

Consequently, prophylactic surgery is the best option

for ♀ who have completed their families.*

*Manchanda et al. Curr Opin Obstet Gynecol 21:31-38, 2009.

Schmeler et al. N Engl J Med 354: 261-269, 2006.

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N Engl J Med 354: 261-269, 2006

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Fallopian tube carcinomas may be common sites

of primary carcinoma in Hereditary Breast Ovarian

Cancer syndrome and the Lynch syndrome.

• 15/58 (26%) registered “ovarian” carcinomas in

BRCA1 mutation carriers may have arisen in a

fallopian tube.

• 1/7 (14%) registered “ovarian” carcinomas in BRCA2

mutation carriers may have arisen in a fallopian tube.

• 5/14 (38%) registered “ovarian” carcinomas in MLH1,

MSH2 and MSH6 mutation carriers may have arisen in

a fallopian tube.

From Casey MJ et al., Presented at the NEAGO Annual Meeting, 2010 (Abstracts).

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Targeted CRC Screening

Screening is melded to LS’s natural history:

Proximal location colonoscopy

Early age of onset beginning at age 25

Accelerated carcinogenesis every 1-2 yrs < age 40,

then annually

Pattern of extracolonic cancers targeted screening

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Family Information Service (FIS)

Cost-effective and highly efficient way of

educating and counseling all available family

members from a geographic catchment area

during a single setting.

Makes best use of physician’s time and effort,

has group therapy potential and patients

welcome it.

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Genetic Disorders Predisposing to

Pancreatic Cancer

• FAMMM syndrome

• Hereditary pancreatitis

• Lynch Syndrome II

• Hereditary breast cancer (BRCA2)

• Ataxia Telangiectasia

• A single family with insulin dependent diabetes

mellitus and nine cases of pancreatic cancer

(concordance) through three generations

• Peutz-Jegher’s syndrome

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Genetic risk of pancreatic cancer Syndrome Mutated

Gene

PanCan Risk Reference

Peutz-Jeghers STK11 (19p13)

RR 132 (44-261) Gastroenterology

199 (2000)

Hereditary

Pancreatitis

PRSS1 (7q35)

SPINK1 (5q31)

50-fold Pancreatology

1:431 (2001)

Cystic Fibrosis CFTR (7q35) 30-Fold NEJM 339 (1998)

FAMMM p16 (9p21) 13-22 Fold NEJM 333 (1995)

FAP APC (5q13) RR 4.5 (1.2-11.4) Gastroenterology

123 (2002)

Hereditary

Breast/Ovarian

BRCA1 (17q21)

BRCA2 (13q12)

RR 2.26 (1.2-4.0)

RR 3.51 (1.9-6.6)

JNCI 94 (2002)

JNCI 91 (1999)

HNPCC MLH1 (3p21)

MSH2 (2p16)

Increased Cancer 78 (1996)

AT ATM (11q23) Increased ClinGen 55(1999)

von Hippel-

Lindau

VHL (3p25) Increased Cancer Research

62 (2002)

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