Hereditary Genetics Syndromes Flashcards
Which cancers have genetic linkages?
- colorectal cancer
- prostate cancer
- pancreatic cancer
- ovarian cancer
- breast cancer
- malignant melanoma
What is the most common cancer in women worldwide?
breast cancer
What is the second most deadly cancer after lung cancer?
breast cancer
What is the lifetime risk for breast cancer?
10-13%
What percentage of breast and ovarian cancer are attributed to genetics?
only 5-10%
What are risks as predictors of breast cancer?
- age
- gender
- family history
Hereditary breast cancer is caused by?
pathogenic variant of either BRCA1 or BCRA2
Hereditary breast cancer has what type of inheritance pattern?
autosomal dominant with high penetrance
Who can carry pathogenic variants in BCRA1 and BRCA2?
Men and women
Increased risks of hereditary breast cancer due to what in certain groups?
founder effect
BRCA1 and BRCA2 mutations are more prevalent in which population?
Ashkenazi Jews
Who do you have to review when you have an Ashkenazi Jew who has hereditary breast cancer?
- review both sides of the family
- if either one first-degree relative has been diagnosed with breast cancer OR two second-degree relatives
- consider genetic counseling
What genes are tumor suppressor genes that:
- control cell growth and death
- repair damaged DNA/preserve chromatid structure
- genomic stability
- transcription regulation
- cell cycle control
BRCA1 and BRCA2
Increased translocations, inversions, deletions, and fusions of non-homologous chromosomes is consistent with what?
cells with abnormal or deficient BRCA1/2
What types of cancers are associated with BRCA1 and BRCA2 mutations?
- breast cancer (male and female)
- ovarian, fallopian, or primary peritoneal
- pancreatic
- prostate
Which BRCA mutation is associated with a higher lifetime risk of cancer?
BRCA 1
In male breast cancer, the BRCA2 mutation increases lifetime risk to what?
2-7% (from 0.1%)
The main age of diagnosis of cancer is younger with which BRCA mutation?
BRCA1
Men with HBOC has an increased susceptibility to what?
- breast cancer
- skin cancer
- prostate
Men with HBOC have a higher risk with which BRCA mutation?
BRCA 2
What should you suspect with any of the following:
-onset of breast cancer prior to 50
-breast cancer at any age with Ashkenazi Jewish ancestry
-multiple primary breast cancers in one or both breasts
-two or more relatives with breast cancer, one diagnosed at or before age 50
-three or more breast cancer relatives
-male breast cancer
-“triple negative” receptor breast cancer
-ovarian cancer
-pancreatic or prostate cancer combined with breast or ovarian cancer in family/individual
-known familial mutation of HBOC
HBOC
What is the 2nd most common gynecologic malignancy?
ovarian cancer
What is the main common cause of gynecologic cancer death?
ovarian cancer
Approximately what percent of ovarian cancers are related to HBOC?
20%
Women with what mutations have more multifocal disease and more aggressive tumors for ovarian cancer?
BRCA 1 and BRCA 2 mutations
What are these common symptoms associated with?
-feeling full quickly after starting to eat
-pain in pelvis or abdomen
-bloating
-more urgent or frequent urination
ovarian cancer
Who should you test for HBOC mutations?
women with a personal or family history of breast, ovarian, tubal, or peritoneal cancer or an ancestry associated with BRCA1/2 gene mutations
Who should you not recommend to get tested for HBOC mutations?
women whose personal or family history is not associated with potential harmful BRCA1/2 gene mutations
What are some risk assessment tools for HBOC?
- gail model 2 (used in practice and research; not appropriate with BRCA mutations)
- breast and ovarian analysis of disease incidence and carrier estimation algorithm (used to calculate specific HBOC risk, primarily used in research)
What does an ambiguous genetic test result for HBOC mean?
mutation in either BRCA1 or BRCA 2 that has uncertain link to HBOC
Management of HBOC breast cancer in women with BRCA 1/2 mutations should consist of what?
age 25:
- clinical exam every 6-12 months
age 25-29:
- annual mri with contrast or mammogram
age 30-75:
- annual mammogram and mri with contrast
age >75:
- considered on individual basis
discuss option of risk-reducing mastectomy, consider risk reducing agents
Management of HBOC breast cancer in males with BRCA1/2 mutations should consist of what?
age 35:
- self exam training and education
- clinical breast exam, every 12 months
Management of HBOC ovarian cancer with BRCA 1/2 mutations should consist of what?
- risk reducing salpingo-oophrectomy
- age 35-40, upon completion of child bearing
- RRSO could be delayed in BRCA2 carriers until age 40-45 because of later age onset
- consider risk reducing agents
- transvaginal ultrasound and CA-125 maybe at the clinicians discretion
Management of HBOC prostate cancer with BRCA 1/2 mutations should consist of what?
age 45:
- recommended screening for BRCA2 carriers
- consider screening for BRCA1 carriers
Management of HBOC pancreatic cancer and melanoma with BRCA 1/2 mutations should consist of what?
- individualized based on family history
What is the average age for colorectal cancer?
- males: 68
- females: 72
What is the lifetime risk of colorectal cancer in the general population?
5%
Rates of what cancer is higher in males and african-americans?
colorectal cancer
Incidence of colorectal cancer is higher in people of lower socioeconomic status due to what?
- physical inactivity/obesity
- poor diet
- tobacco use
- lower rates of colorectal screening
What is colorectal cancer highly influenced by?
genetics, diet, and environment
What are these symptoms associated with:
- hematochezia or melena (black stool)
- unexplained weight loss
- prolonged diarrhea or constipation
- cramping abdominal pain
- abdominal distention, gas pain, distention, fullness
- vomiting
- decreased energy
colorectal cancer
One of the first signs of colorectal cancer may be what?
anemia
New onset anemia in an elderly patient is what until proven otherwise?
colon cancer
What are the different types of polyps?
- adenomatous (higher risk of cancer)
- non-adenomatous (some cancer risk(
- inflammatory (no cancer risk)
What percent of CRC is familial?
15-30%
Hereditary CRC can be a result of what?
single gene or multiple gene mutations (and combo of genetics and environmental factors)
What are the two hereditary colorectal cancer syndromes?
- familial adenomatous polyposis (FAP)
- hereditary nonpolyposis colorectal cancer (HNPCC)
What are the two types of FAP?
- classic FAP
- attenuated FAP
What genes are associated with both classic and attenuated FAP?
- APC gene
- MYH/MUTYH gene
What gene is associated with the most common mutation in FAP?
APC gene (adenomatous polyposis coli gene)
What does the normal APC gene do?
regulates cell division and act as tumor suppressor
FAP associated with the APC gene has what type of inheritance pattern?
autosomal dominant with near complete penetrance (25% are de novo)
What type of FAP gene is less common than APC mutations?
MYH/MUTYH gene
What does the normal MYH/MUTYH gene do and what does the variant do?
tumor suppressor and variant results in DNA damage due to base pair mismatch
FAP associated with the MYH/MUTYH gene has what type of inheritance pattern?
autosomal recessive
What is the lifetime risk of colon cancer in classic FAP?
100%
In affected FAP pts, what is the average age of onset of colon cancer?
39
Classic FAP has how many polyps?
greater than 100, can be thousands
Once diagnosis of classic FAP is established, what is recommended?
colectomy, usually before 20
Individuals with attenuated FAP develop how many polyps?
fewer, typically less than 100
What age do polyps develop in individuals with attenuated FAP?
44 years old
What is the lifetime risk of colon cancer in individuals with attenuated FAP?
70-80%
What is the mean age of colon cancer with AFAP?
56
The location of the mutation within the APC gene has been associated with what?
- severity of colonic polyposis
- degree of cancer risk
- age of cancer onset
- survival
Where are the locations of mutations in classic FAP?
middle of the gene
Where are the locations of mutations in attenuated FAP?
ends of genes
If genetic testing cannot be done in individuals with suspected FAP, what should pts do?
undergo yearly colonoscopies beginning at age 12
What is commonly known as lynch syndrom?
hereditary nonpolyposis colorectal cancer
Lynch syndrome develops how many polyps?
less than 100
In lynch syndrome, the polyps are what?
- larger and flatter
- undergo rapid transformation to cancer
Lynch syndrome usually occurs at what age compared to colorectal cancer that is not inherited?
45 vs 65
Lynch syndrome progresses from a normal colonoscopy to cancer in how many years?
2-3 years
What are these malignancies associated with:
- uterine cancer (endometrial)
- ovarian cancer
- gastric cancer
- small bowel cancer
- biliary tract cancer
- upper urinary tract cancer
- pancreatic cancer
- skin cancer
- brain cancer
Lynch syndrome
What are the top associated malignancies with lynch syndrome?
- colorectal
- uterine
In lynch syndrome, the most common site of extracolonic cancer is?
the uterus (endometrium)
What is this associated with:
- at least 3 relatives with lynch syndrome associated cancer
- one should be a first-degree relative of the other two
- at least two successive generations should be affected
- at least one member diagnosed before age 50
- FAP should be excluded in colorectal cancer cases
- tumors should be verified by pathology
Amsterdam II criteria to identify carriers for lynch syndrome
What is the inheritance pattern of lynch syndrome?
autosomal dominant
What occurs with a defect in one of the mismatch repair genes: MLH1, MSH2, MSH6, and PMS2?
lynch syndrome
MSH6 mutations have higher risks of what?
endometrial cancer
At what age should you start colonoscopies if your have lynch syndrome?
age 25
How should you screen for endometrial and ovarian cancer?
- pelvic exam
- blood test (CA125)
- transvaginal ultrasound
- endometrial biopsy at 25-35
What is the name for a hamartomata’s polyposis syndrome?
Peutz-jehgers syndrome
Peutz-jehgers syndrome mutation occurs on which chromosome?
19
What is the inheritance pattern for Peutz-jehgers syndrome?
autosomal dominant
What are these manifestations associated with:
- melanocytic macules on lips, perioral, and buccal regions
Peutz-jehgers syndrome
Those with Peutz-jehgers syndrome have an increased risk of cancer of what?
- GI tract: COLON, stomach and small bowel
- breast cancer
- pancreatic cancer