Lec 14- What is cancer Flashcards
1
Q
Introduction
A
- The last 20 years has seen a better understanding of the causes and improved treatments of cancer
- There are over 200 forms of cancer- and probably a lot more than this at the genetic level
- Early detection technology has improved the prognosis of cancer patients
- Symptoms of cancer often initially misdiagnosed
- Approx 300,000 new cases diagnosed per year in UK
- 1 in 3 develop cancer, 1 in 4 deaths from cancer
- Early detection and improvements in therapy have improved prognosis- 15,600 to 12,300 per 100,000
2
Q
Cancer
A
- Cancer is a term used to describe a large group of diseases that are characterised by cellular malfunction
- Healthy cells are programmed to respond to their local environment- life and death signals continually received; without +ve signals most cells programmed to die
- Cancerous cells have lost this programming and therefore grow and replicate ‘out of control’
- Decreased requirement for signals and contact/anchor
- De-differentiate (loss of specific function)
- These cells are termed a neoplasm.
3
Q
Different types of cells
A
- Blood cells- erythrocytes, monocytes
- Muscle cells- smooth, striated, cardiac
- Nerve cells
- Bone cells
- Cartilage cells
- Liver cells
4
Q
Healthy cells
A
- Cells represent the basic functional unit of our existence. Carry out metabolism, reproduction, day to day functions
- Cells have specialized functions
- Most cells can grow and replicate
- Repair body organs
- The genetic material (DNA/RNA) and the immune system regulate this process
5
Q
Tumours- Benign
A
- Non-cancerous
- Enclosed in a fibrous shell or capsule
- Take up space- can interfere with surrounding tissues or vessels, impede the function of the body, look unpleasant
- May secrete excess hormones/other factors
6
Q
Tumours- malignant
A
- Cancerous
- Invades surrounding tissues
- Become uncontained- metastasis
- Loose function (de-differentiate)
7
Q
Types of cancer
A
- Carcinomas- epithelium derived
- Sarcomas- mesenchymal derived (Soft tissue)
- Leukemias- blood and bone marrow (haematopoietic)
- Lymphomas- lymphocytes (lymphoid tissue, immune system)
- Germ cell- testicle and ovary
- Blastoma- precursor cell, not terminally differentiated
8
Q
Describing cancer
A
-
Staging of cancer
- TNM: Tumour, lymph node, Metastasis
- Staging 0-4
- Stage 0= no evidence - non-invasive
- Stage 1= small tumour with no spread to local LN
- Stage 2= based on size or spread to local LN
- Stage 3= based on size and spread to local or more distant LN
- Stage 4= fully metastatic spread to distant parts of body
9
Q
An overview of cancer
A
-
Cellular change/mutation theories
- Spontaneous errors
- External agents
- Oncogenes
-
Risks for cancer-lifestyle
- Smoking among greatest
- Nutritional/exercise
10
Q
Errors in DNA replication
A
11
Q
What causes cancer
A
-
Biological factors
- Genetic predisposition
- Reproductive and hormonal risks
- Chemicals in foods- Na nitrate, C.botulism
- Viral factors- herpes related virus and human papillomavirus
-
Medical factors
- Diethylstibestrol (DES)
- Chemotherapy
-
Occupational and environmental factors
- Asbestos, nickel, chromate
- Radioactive substances
- Social and psychological factors- stress and negative emotion
12
Q
Risk factors (multi-factional)
A
- Genetic predisposition
- Exposure to cancer-causing agents
- Random cellular mutations
- Hormone exposure (i.e. oestrogen + breast cancer)
- Occupational and environment factors
- Social and psychological factors
- Chemicals in foods
- Viral (HPV, herpes) create an opportunistic environment
- Medical factors
13
Q
Factors believed to contribute to global causes of cancer
A
14
Q
Types of cancer- Breast cancer
A
- 1 in 8 women
- Risk increases with age
- Risk factors supported by research
- Prevention (self-exam and mammography)
- Treatment
15
Q
Types of cancer- Skin cancer
A
- 1.3 million cases of skin cancer
- Treatable: basal or squamous
- Virulent: malignant melanoma
- ABCD rule about melanoma
