Neoplasia 2 Flashcards
What is 2-napthylamine
Industrial carcinogen used in the dye industry which causes malignant neoplasm
What did 2-naphthylamine show
- there is a long delay sometimes decades between carcinogen exposure and malignant neoplasm onset
- the risk of cancer depends on total carcinogen dosage
- there is sometimes organ specificity for particular carcinogens- bladder carcinoma
How does HPV affect DNA
It is a direct carcinogen because it expresses the E6 and E7 proteins that inhibit p53 and pRB protein function respectively which re both important in cell proliferation
How do hepatitis B and C affect the body
They are indirect carcinogens that cause chronic liver cell injury and regeneration
What does helicobacter pylori do
It causes chronic gastric inflammation
What do parasitic flukes do
They cause inflammation in bile ducts and bladdder mucosa increasing the risk for gastric inflammation in bile ducts an bladder mucosa increasing the risk or gastric, cholangio- and bladder carcinomas
How can HIV increase susceptibility to cancer
Acts indirectly by lowering immunity and allowing other potentially carcinogenic infections to occur
Wha are tumour suppressor genes
Genes that inhibit neoplastic growth
What are oncogenes
Genes that enhance neoplastic growth- mutations of proto-oncogenes
What does the RAS gene do
The RAS encodes a protein that is always active ultimately producing a constant signal to pas through the cell cycles restriction point
What does the RB gene
retinoblastoma- It restrains cell proliferation by inhibiting passage through the restriction point
What are the hall marks of cancer
1- self sufficiency in growth signals
2-resistance to growth stop signals
3-no limit on the number of times a cell can divide - cell immortalisation
4- sustained ability to induce new blood vessels- angiogenesis
5- resistance to apoptosis
6-the ability to invade and produce metastasis
What are promotors
That cause sustained proliferation
Wha are initiators
Cause mutation in DNA
what is the adenoma-carcinoma sequence
ordered sequence of mutations that need to occur in specific genes in a specific order
the accumulation of mutations that normal epithelium undergoes to become the carcinoma
early adenoma, late adenoma carcinoma in situ, invasive carcinoma
What is T IN TNM
Size of the primary tumour and is typically expressed as T1 through fo T4
N in TNM
Extend of regional node metastasis
M in TNM
denotes the extent of distant metastatic spread
Stage 1
Early Local disease
Stage 2
Advanced local disease N0 M0
Stage 3
Regional metastasis
Any T, N1 or more, M0
Stage 4
Advanced disease with distant metastasis
Any T, Any N and M1
How is lymphoma staged
Ann Arbor staging.
G1 stage
Well differentiated
G2
Moderately differentiated
G3
Poorly differentiated
G4
Undifferentiated or anaplastic
When is the grading systems used
Squamous cell carcinoma and colorectal carcinoma
How is cancer treated
Surgery
Radiotherapy
Chemotherapy
Hormone therapy
Adjuvant therapy
After surgical removal of a primary tumour to eliminate subclinical disease
Neoadjuvant treatment
Given to reduce the size of primary tumour prior to surgical excision
What is radiotherapy
Focused on the tumour with shielding of surrounding healthy tissue
Given in fractionated doses to minimise damage to normal tissue
Hormone therapy
Selective oestrogen receptor modulators (SERMs), such as tamoxifen, bind to oestrogen receptors, preventing oestrogen from binding. They are used to treat hormone receptor- positive breast cancer. Androgen blockade is used for prostate cancer.
What do trastuzamab and Imatinib work
Identify cancer specific alterations such as oncogene mutations which provide an opportunity to target drugs specifically at cancer cells
how is the dye industry involved in cancer
2-napthylamine was a chemical used in the dye manufacturing industry. However, it was later found to be a carcinogen which causes bladder cancer, so is now no longer used.
what is an oncogene
A mutated proto-oncogene
normal function of p53
Normally encodes for a transcription factor involved in repairing DNA.
Repairs damage in the S phase of the cell cycle or causes apoptotic cell death if the damage is too extensive.
what is the 2 hit hypothesis
a person with a germline mutation of a tumour suppressor gene on one chromosome is more likely to develop a neoplasm. If one tumour suppressor gene is inherited as mutated – the “first hit” - then the second gene can still protect the cell to supress tumour growth. However, if the second gene becomes mutated and the cell is no longer protected – the “second hit” – then the chance of tumour growth is very high.
what is RAS
a proto-oncogene
Codes for a G protein which signals for a cell to get past the restriction point in the cell cycle.
A mutation causes this protein to always be active, and therefore the cell constantly moves through the cell cycle and divides.
what is HER-2
- Codes for growth factor receptors.
- Overexpression of this gene leads to many growth factor receptors being expressed on the tumour cell surface, increasing the sensitivity of the cell to growth factors.
- This accelerates growth of the neoplasm, and is particularly associated with breast cancer.
what is xeroderma pigmentosa
reduced ability to repair UV damage, and therefore they are more likely to develop skin cancer at a young age.
familial breast carcinoma
associated with mutations to the BRCA1 or BRCA2 genes, which are normally involved in repairing double strand DNA breaks.
Hereditary non-polyposis colon cancer (HNPCC)
condition affecting DNA mismatch repair genes, which increases the risk of developing colon cancer.
what are the 6 hallmarks of cancer
Self-sufficiency in growth signals
Resistance to growth stop signals
Cell immortalisation through the action of telomerase
Angiogenesis; the ability to produce new blood vessels
Resistance to apoptosis
Ability to invade and produce metastases
