Anticancer Drugs Flashcards
Cancer that causes the most deaths in both sexes
Lung cancer
Overall trend of cancer death rates in recent years
Decreasing
Most common cancer treatments
Surgery, radiation, chemo
Goal of anticancer drugs
To destroy all cancer cells
3 main functions of anticancer drugs
Act on DNA, inhibit chromatin function, act on hormone receptors
Carcinoma
Cancer of epithelial cells
Sarcoma
Cancer of muscle, bone, cartilage, fat, connective tissue
Leukemia
Blood cancers that originate in bone marrow and result in underdeveloped blood cells
Lymphoma
Group of cancers in lymphocytes
Blastoff
Cancer in precursor cells
Cancer cell stages
Initiation, promotion, progression
Tumour progression depends on
Mutation/epigenetic alteration rate, selective advantage, proliferation rate, invasiveness
Critical cancer genes
DNA repair genes, genes maintaining chromosome integrity, oncogenes, tumour suppressor genes
3 outcomes of a diseased cell
Apoptosis, senescence, cancer
Oncogene
Normally increases mitosis; can become constitutively active
Tumour suppressor genes
Normally suppress mitosis; can lose function
Angiogenesis
Tumours secrete growth factors to induce blood vessel growth
Metastasis
Detachment from parent tumour → enter blood vessel → proliferate in new environment
When chemotherapy is used
In addition to radiation or surgery, to cure, in palliative care
What cells anticancer drugs are most effective against
Rapidly dividing cells
Cell cycle checkpoints
G1, g2, metaphase
G1 checkpoints
Checks for nutrients, growth factors, and DNA damage to make sure all is ready to synthesize
G2 checkpoint
Checks for cell size and DNA replication
Metaphase checkpoint
Checks for chromosome spindle attachment
When drugs are most toxic in the cell cycle
S Phase, some also M
Growth fraction
The percent of dividing cells that are sensitive to chemotherapy
What phase of the cell cycle most drugs are ineffective in
G0
Debulking
Shrinking tumour, which stimulates proliferation
Early metastases
Have a high growth fraction
Use of several chemo cycles
Synchronizes cells
Log kill
Amount of cells that are killed in each treatment due to first order kinetics
Therapeutic index of anticancer drugs
Very narrow
Factors that influence patient survival
Nature of the cancer, pharmacology, patient
Causes of failure of anticancer drugs
Lack of specificity and resistance
Major sites of toxicity of anticancer drugs
Bone marrow, gi tract, hair follicle, reproductive tract, 2° carcinogenicity
Resistance to anticancer drugs
Natural, acquired, or multi drug resistance
Treatment regimen of chemo
Usually given in combination, as frequently and as close to maximal effective dose as possible
Dosage is based on
Body surface area, pharmacokinetics, interactions, impacts on systems
Considerations for chemotherapy
Long-term gain versus risk, successful treatment versus qualify of life
Cyclophosphamide mechanism of action
Transfers an alkyl group to N7 or O6 of guanine to one or two DNA strands, resulting in monoalkylated or crosslinked strands
Cells most sensitive to cyclophosphamide
Proliferating cells
Most commonly used alkylating agent
Cyclophosphamide
Cyclophosphamide routes of admin
Oral or IV
Fates of aldophosphamide
To the cytotoxic phosphoramide mustard that binds the DNA, or to acrolein - toxic metabolite