Intro To Cancer Genetics- Lecture 9/30/21 Flashcards
% of heritable cancers
~10%
Tumor suppressor
Loss of function, loss of both alleles required, cause of almost all hereditary cancer syndromes
Oncogene
Gain of function
Mutation of a single allele is sufficient
rarely inherited
Hereditary cancer red flags (6)
- Early onset (<50)
- Multiple or bilateral tumors
- Rare or unusual tumors
- Combinations of certain cancers
- Multiple generations affected
- Lack of known contributing factors
BRCA1 and BRCA2 cancer
Female breast, ovarian
Male breast prostate
Pancreatic
Melanoma (BRCA2 only)
BRCA red flags (7)
- Early onset breast cancer
- Two primary breast cancers
- Triple negative breast cancer
- Ovarian cancer
- Male breast cancer
- Multiple BRCA related cancers in family
- Ashkenazi Jewish ancestry
Triple negative breast cancer
Negative for estrogen receptor, progesterone receptor, and HER2 mutations
Other breast cancer predisposition genes (3)
- PALB2
- ATM
- CHEK2
Lynch syndrome
Hereditary Non-poly posits Colon cancer, polyps don’t occur more often, but develop to cancer faster
Li-Fraumeni
TP53 mutation, very very high lifetime risk of cancer
Familial adenomatous Polyposis (FAP)
Defect in APC gene, if untreated 100% risk of developing colon cancer
Benefits of testing (4)
- Increased cancer risk knowledge
- Delineation of family members who are at increased risk
- Insight into cancer developed in an individual
- Increased surveillance
Risks of testing
- Psychological stress
- Ethical concerns regarding autonomy and consent
Limitations of testing
- May be reclassified years after testing
- Does not confer an increased cancer risk
When negative result means there’s no increased risk
When there’s a family member who’s cancer is attributable to a mutation
