Cancer Flashcards
____________ is on of the causes of genomic instability in cancer.
=anomalies in somatic recombination
-homologous recombination rarely occurs in somatic cells
MSH2, MLH1, MSH6, and PMS2, and EPCAM are cause:
Lynch syndrome
What are the 5 key things to know when evaluating a patient with a history of colon cancer?
- Family hx
- Polyps (how many, type, onset)
- Age of onset of colon cancer
- Microsatellite instability in tumor
- Immunohistochemistry for the 4 MMR proteins
What does immunohistochemistry for the 4 MMR proteins tell you? What does it not tell you?
- Tells you which MMR protein is deficient
2. Does NOT tell you whether this is somatic vs germline loss
State the inherited cancer syndrome:
- colorectal cancer
- endometrial
- ovarian
- stomach
- hepatobiliary
- urinary tract
- small bowel
- Brain (CNS)
- sebaceous neoplasm
- pancreas
Lynch syndrome
MSH2, MLH1, MSH6, and PMS2, and EPCAM
A person presents with a history of 25 adenomas and colorectal cancer? What gene should you consider germline testing?
=APC
- consider testing if 20 or more adenomas
- fully penetrant phenotype
A person has a history of 25 adenomas and colorectal cancer. There is no family hx of colon cancer. Should you still consider germline testing?
- Yes!
- 1/3 of APC germline mutations are de novo
Define attenuated FAP
-20-99 adenomatous polyps
+ APC mutation
Define classic FAP
- More than 100 adenomas (colon, also get in duodenum)
- +APC mutation
- usu + family hx
- 100% get colon cancer without colectomy
What are the 2 major types of colon polyps?
- Adenomas
- think FAP if >20 - Hyperplastic
- can be divided into classic hyperplastic and sessile serrated (associated with increased risk of colon cancer)
What hereditary cancer syndrome is caused by mutations in CDH1?
- hereditary diffuse gastric cancer
- Cancers:
1. hereditary diffuse gastric cancer at a young age
2. increased risk for lobular breast cancer
What hereditary cancer syndrome is caused by mutations in STK11?
=Peutz-Jeghers
- key findings: mucocutaneous pigmentation, GI polyposis, increased cancer risk
- usually hyperpigmentation of oral mucosa, palms and soles first sign
- PJS type polyps (hamartomatous gastrointestinal polyps)-can be found anywhere in GI tract but esp in small bowel
- can get polyps outside GI tract
- can still get other types of polyps (adenomas)
What types of cancer is a person with a germline STK11 mutation at risk for?
=Peutz Jeghers -Cancers 1. colon 2 small bowel 3. stomach 4. pancreas 5. breast 6. ovarian 7. testes 8. uterine 9. lung 10. kidney
True or false: the only complication from Peutz-Jeghers type polyps is cancer
- false
- onset of polyps usually in 1st decade of life
- cancer risk from malignant transformation of polyps is unknown
- other risks are obstruction, bleeding, intussusception, ,rectal prolapse
True or false: Juvenile Polyposis refers to histology of the polyps, not age of onset
=true
What cancer syndrome is caused by mutations in SMAD4, BMPR1A?
=Juvenile polyposis
- Hamartomatous GI polyps
- considered in individuals with 5 or more juvenile polyps in colon or GI tract
- Usually some polyps appear in 1st or 2nd decade of life
- Increased risk for colon cancer, gastric and other GI cancer and pancreatic cancer
True or false: most of the time no mutation is identified in familial pancreatic cancer cases.
=true
Mutations in SMAD4 can cause an overlapping condition of what hereditary cancer and what other genetic disorder?
=Juvenile Polyposis/HHT
- often have some features of HHT
- also SMAD4 reported with increased risk for familial thoracic aneurysm so may also need to consider aorta screening
EGFR missense mutations are important in what type of cancer? Why?
=lung cancer
- Specific missense mutations are associated with tyrosine kinase inhibitors
- the acquired T790M variant is associated with resistance to therapy with tyrosine kinase inhibitors
JAK2 mutations are important for what type of cancer?
=associated with high risk ALL and ALL associated with Down syndrome
ALK missense mutations and amplification are associated with what type of cancer?
Neuroblastoma
Specific IDH1/2 gain of function mutations are implicated in what 3 types of cancer?
- brain cancer (astrocytomas and glioblastoma multiforme)
- AML
- sarcomas
What is the molecular target for imatinib?
=BCR-ABL and C-kit
used for CML, GIST