Chemotherapy Flashcards
Why do 60-70% of cancers need systemic treatment such as chemotherapy?
Patient’s die from systemic spread of disease
What type of chemotherapy is neoadjuvant?
Chemotherapy before definitive surgical intervention
What are the aims of neoadjuvant chemotherapy?
To make the tumour smaller to allow less radical surgery, while also treating small occult metastases
In what cancer is neoadjuvant chemotherapy established as treatment protocol?
Osteosarcoma, being trailed for breast cancer
Discuss primary chemotherapy
Initial chemotherapy for a tumour that is inoperable
Reduction in tumour may make surgery with curative intent possible
Does primary chemotherapy increase cure rates?
Yes
What is the use of adjuvant chemotherapy?
Chemotherapy after complete macroscopic clearance at surgery
Chemotherapy in this setting treats the occult microscopic metastases
why is adjuvant chemotherapy important?
Treats occult microscopy metastases that have been proven to lead to relapse after surgery for lymph-node positive disease (e.g. breast or colorectal cancer)
This treatment increases cure rates
Discuss palliative chemotherapy
This aims to improve symptoms and prolong life
The treatment must not worsen a patient’s QoL
Is it justified to give 2nd or 3rd line chemotherapy in a palliative setting?
Yes, if the disease remains chemo-sensitive e.g. breast cancer, ovarian cancer, colorectal cancer, and it is not damaging the patients QoL
Discuss when curative chemotherapy can occur
In some malignancies, there is a real chance of cure even if there is metastatic disease at presentation
This justifies the use of more intensive treatment associated with greater toxicity
Which cancers are suitable for curative chemotherapy?
Germ cell tumours, Hodgkin’s disease, Non-hodgkin’s lymphoma and many childhood cancers
Discuss some prophylactic treatments
Hormonal treatments may be given before overt malignancy appears - Tamoxifen for in-situ breast cancer before invasive carcinoma is recognised
Why are chemotherapies often given in combination?
- Different classes of drugs have different actions - kill more cancer cells together
- Less chance of drug-resistant malignant cells emerging
- drugs have different sites of toxicity, dose can be maintained for each drug
When is single agent Chemo appropriate?
Low performance status
Palliative setting
In which cancers are high dose, incredibly toxic, treatments justified?
Hodgkin’s disease
Ewings sarcoma
Is prolonged chemotherapy appropriate in remission?
Evidence suggests little advantage in most cancer, as resistant clones develop and toxicity increases
Used in childhood leukaemia, chemo is given for 18 months as maintenance following the induction of complete remission
Which cytotoxic drugs are available orally?
Cyclophosphamide, etoposide, capecitabine and tamoxifen
What are the advantages of oral chemo?
Patient does not have to have lengthy hospital visits and invasive procedures
When is intravesical chemotherapy used?
Superficial bladder cancer
Produces high doses at the site of the tumour with negligible systemic absorption - minimal systemic toxicity
When is intraperitonal chemotherapy used?
For tumours that have spread trans-coelomically e.g. ovarian cancer
When is intra-arterial chemotherapy used?
Any tumour that has a well-defined blood supply has the potential
e.g. hepatic artery infusion for liver metastases
Allows higher doses to be delivered to the involved site and reduces systemic toxicity
How are chemotherapy doses calculated?
They are calculated according to the patients Body Surface Area (BSA), using DuBois formula
Which chemotherapy drug has it’s dose calculated directly from renal function?
Carboplatin