LMP301 Lecture 14: Cancer Flashcards
Most common cancer for men
prostate
most common cancer for women
breast
every year, there are the most deaths from __ cancer
lung
What is the leading cause of death in Canada right now?
cancer
define: neoplasia
"cancer" new growth (called "neoplasm")
define: tumour
Swelling; neoplasm
define: oncology
study of tumours / neoplasms
define: cancer
common term for all malignant tumours
Cancer is a ___ process
multistep
What happens to cancer cells?
- loses stability for differentiated state
- go back to “stem cell” stage
- divide uncontrollably
What is it called when cancer invades other parts of the body?
Metastasis
clonal theory of tumorigenesis
Cancer cells clone themselves repeatedly to form a neoplasm
Etiology of cancer (3 steps)
- initial DNA damage
- chromosome breakdown & rearrangement
- selection of successfully growing mutant cells
Example of things that can lead to initial DNA damage
- carcinogens
- radiation
- chemicals
- viruses
- unknown
What happens during chromosome breakdown & rearrangement?
loss of growth control leading to a loss of chromosome stability
What happens during selection of successfully growing mutant cells?
- new patterns of gene expression (expression of oncogenes, inhibit tumour suppressors)
- tumour production
What is seen with cancer cell diversity? (5)
- the same tumour can have different gene expression
- things produced by each tumour cell can be different (used as markers)
- clinical symptoms can change over time
- new symptoms appear when cancer spreads
- difficult to predict response to treatment due to high diversity
Stages of cancer (4)
- Induction phase
- In situ phase
- Invation phase
- Dissemination (metastasis)
How long can induction phase last?
up to 30 years
What is the ideal stage to detect cancer?
induction phase
Local effects of cancer will lead to…
- obstruction of blood vessels & ducts
2. destruction of tissue
Consequences of cancer (2)
- systemic effects
2. cachexia
What are the systemic effects of cancer? Which one is more commonly seen?
- ectopic secretion of hormones
- SIADH (more common)
Example of ectopic secretion of hormones?
Lung cancer: small cell carcinomas product ACTH (more cortisol)
Result of SIADH?
- water retention
- hyponatremia
define: cachexia
weakness and wasting of the body due to severe chronic illness
Symptoms of cachexia (7)
- anorexia
- lethargy
- weight loss
- muscle weakness
- anemia
- pyrexia
define: pyrexia
fever that can’t be explained by any cause
What happens if someone is experiencing cachexia?
- no appetite -> inadequate food intake
- impaired digestion & absorption
- tumour using up all nutrients
- increased metabolic rate to support tumour growth
What biochemical parameters change in those with cancer?
- liver aminotransferases (ALT, AST)
- adrenal abnormalities (cortisol)
- elevated urate, lactate dehydrogenase, calcium
- proteinuria, renal failure
Maker for liver damage due to cancer
ALT
AST
maker for adrenal gland damage due to cancer
cortisol
maker for kidney damage due to cancer
proteinuria
treatment for cancer
- chemotherapy
- radiation
Consequences of chemotherapy
- cytotoxicity
- tumour lysis syndrome
- hyperuricemia
- hypomagnesemia
Consequences of radiation
- hypopituitarism
- gonadal failure
tumour lysis syndrome (TLS)
group of metabolic complications that can occur after treatment of cancer
hyperuricemia
level of uric acid in the blood that is abnormally high
hypopituitarism
diminished hormone secretion by the pituitary gland
Process of lab testing / responsibilities for cancer
- detection / screening
- confirmation (biopsy)
- classification (biopsy)
- monitoring
What is used to screen for breast cancer?
mammography
What is used to screen for colon & rectum cancer?
fecal occult blood-sigmoidoscopy
What is used to screen for lung cancer
x-ray
cytology of the sputum
What is used to screen for cervix cancer
Papanicolaou test (pap test)
classification of cancer determines the ___ and ___ of the tumour
staging & grading
define: tumour marker
a substance which is released by the tumour or the host in response to the tumour
their presence / increased expression can be used to determined presence of a tumour
characteristics of an ideal tumour marker (5)
- easy to measure (see in plasma)
- abundant in body fluids
- specific for certain type of cancer
- sensitive for small tumours
- diseased state will increase the marker
Tumour markers are classified into…
- proteins
- enzymes
- hormones
- oncofetal antigens
- carbohydrates
- hormone receptors
- genetic markers
marker for end stage renal failure?
Bench Jones proteins
Protein markers for cancer (2)
- immunoglobulins
- Bence Jones proteins
enzyme markers for cancer (3)
- lactate dehydrogenase
- alkaline phosphatase
- prostate specific antigen
hormone markers for cancer (3)
- HCG
- ACTH
- catecholamines
oncofetal antigen markers for cancer (2)
- CEA
- AFP
What are oncofetal antigens?
Antigens produced during early development of the fetus, but should not be present after that stage
carbohydrate markers for cancer (3)
- CA 19-9
- CA 125
- CA 15-3
hormone receptor markers for cancer (2)
- estrogen
- progesterone
genetic markers for cancer (6)
- Ras
- Myc
- HER-2/neu
- p53
- BRCA 1
- BRCA 2
Clinical utility of tumour markers (5)
- monitoring treatment
- follow up / reoccurence
- prognosis
- diagnosis (CAN’T BE USED ALONE)
- screening of high risk populations (not very sensitive / specific)
Marker for prostate cancer
PSA
Marker for breast cancer (3)
- estrogen & progesterone receptors
- CA27.29
- CA15-3
Marker for colorectal cancer
CEA
Marker for testicular cancer
AFT
Marker for ovarian cancer
CA 125
Marker for hepatoma
AFP
Marker for thyroid cancer
calcitonin
Marker for adrenal cancer
catecholamines
thyroid cancer is also known as…
medullary carcinoma
PSA is produced by the…
prostate epithelium
Advantages of PSA
organ specific
Disadvantages of PSA
not cancer specific; can also be caused by…
- growth of prostate (benign prostate hyperplasia)
- inflammation of prostate (prostatitis)
Clinical utility of PSA
- early detection of prostate cancer
- stage of cancer
- monitor patient
How can PSA be made more cancer-specific?
- free vs. total PSA
- ## age specific reference intervals
Who has more PSA: older or younger?
older
PSA
prostate specific antigen
define: pheochromocytoma
neuroendocrine tumour of the adrenal gland (medulla)
–> secrete high amounts of catecholamines
What is multiple endocrine neoplasia (MEN)?
- inherited tumour predisposition syndrome (AD)
- tumours in 2 or more endocrine glands
- tumours overproduce hormones
MEN 1 is due to…
mutations in MEN 1 gene
MEN 1 gene is a…
tumour supressor
MEN2 is due to…
mutations in Ret gene
Ret gene is a …
Tyrosine kinase receptor (protein)
Symptoms of MEN 1 (what is usually affected?)
- parathyroid adenomas
- pancratic adenomas
- pituitary adenomas
- adrenal cortex adenomas
- carcinoid tumours
define: carcinoid tumours
a tumor of a type occurring in the glands of the intestine (esp. the appendix) or in the bronchi
symptoms of MEN 2 (what is usually affected?)
- medullary carcinoma of the thyroid
- phaeochomocytoma
- hyperparathyroidism
Which geographic / racial groups are more predispositioned to what type of cancer?
- stomach cancer in Japan
- lung carcinoma in USA
What environmental factors increase risk of cancer?
- asbestos
- smoking
Which age groups are more at risk for cancer?
> 55
Which cancers are due to genetics?
- 5% of breast cancer
- MEN
- pediatric lukemias
- lymphomas
which genes are responsible for breast cancer?
brca1 and brca2
define: lympohas
cancer of the lymph nodes
Acquired preneoplastic disorders
Some diseases increase risk of getting cancer
preneoplastic = before tumour formation
???
Children are most affected with which type of cancer?
- leukemia
- lymphomas
- CNS
