Principles of Systemic Anti-Cancer Therapy Flashcards
What are the different principles of cancer therapy?
Surgery
Radiotherapy
Cytotoxic chemotherapy
Targeted
Immunotherapy
Advanced therapy medicinal products
Hormonal - breast + prostate cancer
How do you decide which therapy?
Which cancer
Stage of disease
Molecular diagnosis = mutations = targeted
Performance status - measure of patient’s everyday function
= if status low based on disease = treat then can function
BUT different to someone who is frail to begin with
Treatment availability = NOT all funded by NHS
What factors affect tumour growth rate?
Type of cancer
Stage of disease
Doubling time
What is doubling time?
Time taken for the number of cancer cells to double varies significantly among cancer types
Describe detectable malignancy threshold and lethal tumour burden
Detectable = 109
Lethal = 1012
Time between depends on doubling time of cancer
Even below detectable number chemo is given to prevent resistance + relapse
What is the problem with chemo?
Kills normal body cells = rapidly dividing cells
= anaemic, prone to infection (decreased WBC)
What is the aim of curative chemo?
To cure the cancer
What is the aim of adjuvant chemo?
Given after surgery or radiotherapy
Eradicate micro metastases = decrease chance of relapse
Improve cure rate
What is the aim of neoadjuvant chemo?
Given prior to surgery or radiotherapy
To improve success
Shrink large tumour to make it more operable
What is the aim of palliative chemo?
NOT just given in end of life
Incurable BUT can still live long time
Used to control symptoms + improve quality of life
Prolong life
How is chemo given?
Combination of drugs = target different parts of cell cycle = decrease resistance
Prescribed in cycles
Usually 3-4 week
All drugs may be given on day 1 or can be given at different time points
Number of cycles vary
What are the methods of delivery of chemo?
IV infusion/bolus given with saline/glucose to flush out body
Through the bladder - bladder cancer
S/C
Preventative intrathecal
Orally - newer targeted therapies - oral more targeted than IV = less SEs
What are the advantages of oral chemo?
More convenient for patient
Less expensive
Lower toxicity
Avoid complications associated with IV access
What are the disadvantages of oral chemo?
Adherence
Variable plasma = unknown plasma dosage
Drug interactions
Toxicity profiles of newer agents
N+V
Monitoring of SEs = patients don’t want to say if they’re experiencing SEs
How are chemo doses calculated?
Using body surface area
BUT dose banding = standardisation
Don’t normally dose monitor = just look at how well patient tolerates it = decrease if NOT tolerated
What are the monitoring requirements for chemo?
Success = tumour markers + imaging - is it working?
Toxicity review = FBC, U+Es, renal function, LFTs, toxicity symptoms + weight
What may happen following review of treatment?
Continued
Stopped = NOT tolerating
Delayed = NOT tolerating or WBC too low
Dose adjusted = NOT tolerating
What is problem with drug resistance?
Cross resistance = become resistance to one drug type most likely become resistant to all
What are targetable therapies?
Identifying targetable mutations
What are immunotherapies?
Target PD-1/PD-L1 - lung cancer
How to prescribe chemo?
Informed consent
Patient needs to know SEs, support they may need, what to expect, potential outcomes
Specialists prescribe
Electronic prescribing system
Regime = anti-emetics + steroids built into the cycle
What is chemo dose banding?
Individualised based on patient’s BSA
Introduced to deliver range of that closely match vial size
Reduces waste + saves money
What is included in calculating chemo dose?
Renal function - super important
USE WRIGHT FORMULATION
DuBois BSA equation
