Genetics of Cancer Flashcards
(blank) is due to a mutation of a gene within a specific cell in the body.The damaged cell reproduces into multiple damaged cells which then accumulate into a (blank)
Cancer
tumor
All cancers are genetic but not all cancer is (blank)
hereditary
What percent of cancer is sporadic?
Familial?
Hereditary?
60%,
30%
7-10%
What type of cancer does this describe
(60%)
“By chance”
Environmental insults & aging damages the DNA within a given cell
sporadic cancer
What type of cancer does this describe
(30%)
Multifactorial
Several genes (not typically known) in combination with several environmental factors
These multiple factors will tend to be shared by family members thereby moderately increasing risk
Familial cancer
What type of cancer does this describe:
10%
Cancer that develops due to the person INHERITING a single gene that is mutated
The mutated gene is in every cell of the body & dramatically increase the risk to develop cancer over the lifetime
Genes have roles in certain parts of the body & therefore a mistake will increase the risk of not just any cancer but cancer in the corresponding area
Because the predisposition is inherited, environment & age play less of a role & cancer typically develops earlier than usual
hereditary cancer
When should you suspect a hereditary cancer?
cancer in 2 or more relatives on same side of fam,
early age diagnosis
multiple primary tumors
bilateral or multiple rare cancers
constellation of tumors consisted with specific cancer syndrome (i.e. breast and ovary)
Evidence of autosomal dominant transmission
What are three types of hereditary breast cancer syndrome?
Hereditary Breast & Ovarian Cancer Syndrome (HBOC)
Cowden Syndrome—PTEN gene
Li Fraumeni—p53 gene
What are the characteristics of Hereditary Breast & Ovarian Cancer Syndrome (HBOC)?
Breast <50
What are the characteristics of Cowden Syndrome (PTEN gene)
Both malignant and benign tumors of the breasts, uterus, thyroid, and skin
What are the characteristics of
Li Fraumeni—p53 gene?
Young breast cancer (20s), childhood adrenocortical tumors, sarcomas, leukemia, etc
Breast cancer before age 50 Ovarian cancer at any age Male Breast Caner Bilateral Breast Cancer Ashkenazi ancestry IS THIS SIGN OF HEREDITARY OR SPORADIC BREAST CANCER?
hereditary
None of the breast cancer is diagnosed before age 50
No ovarian cancer
No clear pattern on one side of family or other
IS THIS SIGN OF HEREDITARY OR SPORADIC BREAST CANCER?
sporadic
BRCA1 and BRCA2 are how common in hereditary breast and ovarian cancer syndrom?
52% and 32%
(blank) Mutations Increase the Risk of Early-Onset Breast Cancer
BRCA1/2
What are the population risk and hereditary risks of Breast Cancer?
By age 40
age 50
lifetime
.5% pop 10-20% hereditary
2% pop 33%-50% hereditary
12% pop 56%-87% hereditary
Women with mutations in BRCA1 and BRCA2 have a greatly elevated risk of (blank) as well as breast cancer
ovarian cancer
The risk of ovarian cancer due to inherited BRCA1 mutations is (blank) by age 70, compared to the general population risk of 1%.
28% to 44%
Mutations in BRCA2 confer an increased risk of ovarian cancer of approximately (blank) by age 70, which represents a 15-fold increase compared to the general population.
27%
Is the location of mutation of BRCA1 or BRCA2 genes linked to likelihood of developing ovarian cancer?
no relationship has been confirmed
BRCA1/2 Mutations Increase the Risk of a Second Primary Breast Cancer:
Pop risk vs hereditary risk in first 5 years of dx?
pop risk vs hereditary risk in lifetime?
5% pop 12%-20% hereditary risk
11% pop 40%-62% hereditary risk
The presence of BRCA also causes a risk in other cancer other than female breast cancer and ovarian cancer, What are these other cancers?
Male breast cancer, Prostate cancer, melanoma, pancreatic cancer
What is the gen pop risk of male breast cancer and what is the risk with BRCA mutation?
less than 1% pop, 7% BRCA
What is the gen pop risk of prostate cancer and what is the risk with BRCA mutation?
15% pop, 20% BRCA
