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Flashcards in incidence, prognosis and treatment of cancer Deck (25)
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What are the 4 most common cancers in the uk?

breast, lung, prostate and bowel


What are the most common cancers in children under the age of 14?

- leukaemia's
- CNS tumours
- lymphomas


Which cancers carry a very good 5 yr survival rate?

- testicular
- melanoma
- breast
- prostate


Which cancers carry a very bad 5 yr survival rate?

- pancreatic
- lung
- oesophageal


What factors must be considered when trying to predict the outcome of a cancer?

- age
- general health
- tumour site
- tumour type
- grade (differentiation)
- stage (size/ spread)
- availability of effective treatments


What is the common system for assessing tumour burden?

TNM staging (T= size of primary tumour, N= regional spread via lymph nodes, M= distant metastatic spread via blood)


Explain how scored are given for each section of the TNM staging system?

T is by size (1,2,3,4)- but it varies
N0 = no lymph spread, N1= regional spread to one lymph node, N2= spread to many nearby lymph nodes
M0= no distant metastasis, M1= distant metasis present


Explain the staging of tumours as I, II, III, IV

I= early local disease
II= advanced local disease (N0, M0)
III= regional metastasis (N1 or more with M0)
IV= advanced with distant metastasis (M1)


What special system is used to stage non-solid lymphomas?

Ann Arbor staging


How does Ann Arbor staging work? (for non-solid lymphomas)

I= single lymph node
II= 2 or more lymph nodes effected but on same side of diaphragm
III=lymph nodes on both sides of diaphragm affected
IV= involvement of one or more extra lymphatic organs such as bone marrow or lung


What system is used to stage colorectal carcinoma?

Dukes staging


How does Dukes staging work? (for bowel cancer)

A= invasion into but not through bowel
B= invasion through cell wall
C= involvement of lymph nodes
D= distant metastasis


What is grading? Describe the system used

- how well differentiated the cancer is
G1= well differentiated
G2= moderately diff
G3= poorly diff
G4= anaplastic/undifferentiated


What ways can cancer be treated?

1. chemotherapy
2. radiotherapy
3. surgery
4. hormone therapy
5. targeted molecular adaptations


What is meant by adjuvant and neoadjuvant therapy?

adjuvant: treatment given after surgery to eliminate subclinical micrometastasis

neoadjuvant: treatment given to reduce the size of the primary tumour prior to surgery


Describe how radiotherapy is given and how it works (4)

- given in fractioned doses to allow time for healthy cells to recover/minimise normal tissue damage
- causes direct or free radical damage to DNA
- especially in cells in G2 phase (therefor targets rapidly dividing tissues more)
- DNA damage such as DS breaks induces apoptosis as dose is so high that lots of damage cannot be repaired


What types of chemotheraputic agents are there? (4)

- Antimetabolites: analogues of normal substances eg fluorouracil inhibits DNA replication as replaces thymine
- Alkylating agents: cross link DNA (cisplatin)
- Antibiotics: many ways- inhibits DNA synthesis mainly (doxorubicin)
- Plant derived drugs block microtubule assembly and interfere with spindle formation (vincristine)


Give an example of a hormone therapy targeting cancers

- tamoxifen (SERM) binds to oestrogen receptors preventing oestrogen binding so treats oestrogen receptor positive breast cancer
- androgen blockades can treat some prostate cancers


What is the benefit of hormone therapy?

- non toxic as very selective to cancer cells


Give 2 examples of oncogenes being targeted to treat cancer

- Herceptin/ trastuzumab blocks HER2 receptor so no inactivates oncogene
- Gleevac/imantinib prevents fusion of two proteins in chronic myeloid leukaemia which cause creates an oncogene


Give an example of a hormone tumour marker

human chorionic gonadotrophin released from testicular tumours - measured for diagnosis


How are tumour markers useful?

- can sometimes be used for diagnosis (although not specific or sensitive enough really)
- mainly used for monitoring tumour burden


What is the limitations of screening programs

- pick up before would even be a problem (lead time bias) so looks like longer 5 yr survival but really isn't
- pick up people whos are so slow growing they'd never be a problem (over-diagnosis)
- pick up slow growing ones more commonly than fast growing (length time bias)


Who are screening programmes meant for?

Healthy people with no symptoms in order to detect cancers as early as possible when chance of cure is highest.


What screening programmes are available in the UK?

1) breast screening - women 47-73 YO
2) Cervical screening - women 25-64 YO
3) Bowel screening - men + women 60-74 YO