116A WEEK 11 – Introduction to cancer
Learning outcomes:
1. Describe the main features of cancer cells
2. Exploring the main types of cancer
3. Understanding how cancers are spread
4. Outline some of the main factors causing cancer
5. Exploring current approaches for treating cancer
What is cancer?
- When abnormal cells undergo mitosis in an
uncontrolled way. Some cancers may eventually
spread into other tissues
- There are more than 200 types of cancer
- 50% of people in the UK will get cancer in their
lifetime
Features of cancer cells
- Cancer cells bypass proliferation controls
Cancer cells vs normal cells
- Cancer cells form tumours
- Cancer cells have anchorage independent growth – which means
they do not need to be attached to a substratum in order to grow
o Normal cells require a matrix
o Cancer cells grow in suspension
- Density dependent inhibition of growth
o Normal cells grow in a monolayer
o Tumour cells divide in all directions
Loss of cell cycle control
- They grow when they should not, their metabolism can reply from
both mitochondrial oxidative phosphorylation as well as from
aerobic glycolysis (ATP from glucose)
- Cancer cells escape cell cycle checkpoints
- They go through cell cycle division when they should not – leads to
increased proliferation
- Abnormal stress responses allow them to survive and continue
, - Dividing in conditions of stress that would arrest or kill normal cells
- They are less prone than normal cells to undergo apoptosis
- They escape replicative cell senescence: they do not age
Normal cells vs cancer cells
Main types of cancer
- Carcinomas arise from epithelial cells that cover external and
internal body surfaces (lung, breast, prostate, colon cancer) – 80-
90%
o Most common form: head and neck squamous cell carcinoma
affects nose/sinus/larynx etc so is not a skin cancer
- Sarcomas develop from supporting and connective tissue such as
bones, cartilages, fat and muscles - ~1%
- Lymphomas and leukaemia arise from cells of lymphatic and blood
origin i.e. B-cells and T-cells - ~7%
- Blastomas arise from the blasts/precursor cells of the embryonic
tissue (e.g. retinoblastoma affects the eye, nephroblastoma affects
the kidney)
Rhabdomyosarcoma
- Rhabdo-myo – means muscle leaks contents into blood
- Sarcoma – means connective tissues
- Often starts in the covering of the lungs but can also affect the
abdomen
- Can also develop among other soft tissues including knees etc. –
doesn’t affect bone
- Good news – chemotherapy treatments are available and long-term
survival is seen
What is the difference between benign and malignant cancer?
- Tumours can be benign (non-cancerous) and malignant (cancerous).
Benign tumours tend to grow slowly and do not spread
- Malignant tumours grow rapidly, invade and destroy nearby normal
tissues and spread throughout the body
- Metastasis is when a cancer migrates to form a new tumour
elsewhere in the body
Learning outcomes:
1. Describe the main features of cancer cells
2. Exploring the main types of cancer
3. Understanding how cancers are spread
4. Outline some of the main factors causing cancer
5. Exploring current approaches for treating cancer
What is cancer?
- When abnormal cells undergo mitosis in an
uncontrolled way. Some cancers may eventually
spread into other tissues
- There are more than 200 types of cancer
- 50% of people in the UK will get cancer in their
lifetime
Features of cancer cells
- Cancer cells bypass proliferation controls
Cancer cells vs normal cells
- Cancer cells form tumours
- Cancer cells have anchorage independent growth – which means
they do not need to be attached to a substratum in order to grow
o Normal cells require a matrix
o Cancer cells grow in suspension
- Density dependent inhibition of growth
o Normal cells grow in a monolayer
o Tumour cells divide in all directions
Loss of cell cycle control
- They grow when they should not, their metabolism can reply from
both mitochondrial oxidative phosphorylation as well as from
aerobic glycolysis (ATP from glucose)
- Cancer cells escape cell cycle checkpoints
- They go through cell cycle division when they should not – leads to
increased proliferation
- Abnormal stress responses allow them to survive and continue
, - Dividing in conditions of stress that would arrest or kill normal cells
- They are less prone than normal cells to undergo apoptosis
- They escape replicative cell senescence: they do not age
Normal cells vs cancer cells
Main types of cancer
- Carcinomas arise from epithelial cells that cover external and
internal body surfaces (lung, breast, prostate, colon cancer) – 80-
90%
o Most common form: head and neck squamous cell carcinoma
affects nose/sinus/larynx etc so is not a skin cancer
- Sarcomas develop from supporting and connective tissue such as
bones, cartilages, fat and muscles - ~1%
- Lymphomas and leukaemia arise from cells of lymphatic and blood
origin i.e. B-cells and T-cells - ~7%
- Blastomas arise from the blasts/precursor cells of the embryonic
tissue (e.g. retinoblastoma affects the eye, nephroblastoma affects
the kidney)
Rhabdomyosarcoma
- Rhabdo-myo – means muscle leaks contents into blood
- Sarcoma – means connective tissues
- Often starts in the covering of the lungs but can also affect the
abdomen
- Can also develop among other soft tissues including knees etc. –
doesn’t affect bone
- Good news – chemotherapy treatments are available and long-term
survival is seen
What is the difference between benign and malignant cancer?
- Tumours can be benign (non-cancerous) and malignant (cancerous).
Benign tumours tend to grow slowly and do not spread
- Malignant tumours grow rapidly, invade and destroy nearby normal
tissues and spread throughout the body
- Metastasis is when a cancer migrates to form a new tumour
elsewhere in the body
