Cancer therapies
Therapeutic Strategy
Anti-Neoplastic agents
Novel Therapies
Radiotherapy
Marie Curie – 1898 – radium
EBRT (external beam therapies) - Potential damage to healthy tissue, Moulds determine the exact
position, Curative doses: Solid tumour 60-80 Gy /Lymphomas 20-40 Gy, Adjuvant doses: 45-60 Gy,
Fractionated: 1.8-2 Gy fractions (5 days/week)
PBT (proton beam therapy) - Synchroton/ cyclotron to speed up and control protons, travel deeper
into tissue, Radiation does not go beyond tumour – very accurate.
Brachytherapy - Radioactive seed implants (LDR ~ 2 Gy/h), Catheter inserted (HDR ~ 12 Gy/h),
Requires anaesthesia, Very localised area, Common radiation source: Iridium-192 (192Ir), Effective
treatment for cervical, prostate, breast, skin cancer.
Basic mechanism of action
Radiation shatters backbone of DNA either via direct damage or via indirect damage (ionisation of
water within tumour to form ROS which damages DNA) and forces cell into cell cycle to either fix
DNA or induce apoptosis. However hypoxic tumours are less effected by this.
Chemotherapy
Main aim is to force cells into apoptosis via various mechanisms
Issues
- cancer cells don’t always divide quickly
- disruption to apoptotic pathways – cytotoxic drugs can fail
- serious side effects/toxicity
Types of cytotoxic drugs
- alkylating agents
- anti-metabolites
- cytotoxic antibodies
- mitotic spindle poisons
- cisplatin/carboplatin
- hormones – glucocorticoids, oestrogens, androgens
- others – asparaginase, interferons, monoclonal antibodies
in solid tumours – 3 types of cells
- A – diving cells
- B – resting cels (G0)
- C – cells no longer able to divide
Dormant cells are targeted and encouraged to divide then are given cytotoxic drugs (anti-
proliferative) – no effects on invasiveness or metastasis.
Therapeutic Strategy
Anti-Neoplastic agents
Novel Therapies
Radiotherapy
Marie Curie – 1898 – radium
EBRT (external beam therapies) - Potential damage to healthy tissue, Moulds determine the exact
position, Curative doses: Solid tumour 60-80 Gy /Lymphomas 20-40 Gy, Adjuvant doses: 45-60 Gy,
Fractionated: 1.8-2 Gy fractions (5 days/week)
PBT (proton beam therapy) - Synchroton/ cyclotron to speed up and control protons, travel deeper
into tissue, Radiation does not go beyond tumour – very accurate.
Brachytherapy - Radioactive seed implants (LDR ~ 2 Gy/h), Catheter inserted (HDR ~ 12 Gy/h),
Requires anaesthesia, Very localised area, Common radiation source: Iridium-192 (192Ir), Effective
treatment for cervical, prostate, breast, skin cancer.
Basic mechanism of action
Radiation shatters backbone of DNA either via direct damage or via indirect damage (ionisation of
water within tumour to form ROS which damages DNA) and forces cell into cell cycle to either fix
DNA or induce apoptosis. However hypoxic tumours are less effected by this.
Chemotherapy
Main aim is to force cells into apoptosis via various mechanisms
Issues
- cancer cells don’t always divide quickly
- disruption to apoptotic pathways – cytotoxic drugs can fail
- serious side effects/toxicity
Types of cytotoxic drugs
- alkylating agents
- anti-metabolites
- cytotoxic antibodies
- mitotic spindle poisons
- cisplatin/carboplatin
- hormones – glucocorticoids, oestrogens, androgens
- others – asparaginase, interferons, monoclonal antibodies
in solid tumours – 3 types of cells
- A – diving cells
- B – resting cels (G0)
- C – cells no longer able to divide
Dormant cells are targeted and encouraged to divide then are given cytotoxic drugs (anti-
proliferative) – no effects on invasiveness or metastasis.
