PA30326 Workshop Lung cancer Flashcards
Mr CS, a 70 yr old male, presented to his GP with increasing cough and breathlessness for past 3 weeks, weight loss of 1 stone over the same period, 2 episodes of haemoptysis and increasing fatigue. Also Mr CS has been a heavy smoker for most of his life (20 cigarettes/day for 50 yrs). His symptoms concerned the GP.
Calculate the number of pack years that Mr CS has been smoking – this is often quoted in hospital medical notes.
(No. of pack years = no. of packs per day x no. of years smoking where 1 pack = 20 cigarettes)
- 50 pack years. No of pack years – linear relationship with cancer risk (although have to take into account whether patient is current or ex smoker, so not totally accurate)
At the suspected lung cancer clinic Mr CS’s medical history is taken, and he has a CT scan of his chest. A biopsy from the left lower lobe is taken using bronchoscopy and sputum cytology is also carried out. Routine lung function tests were also carried out to assess baseline function. A CT scan shows multiple metastases on his liver.
Mr CS’s tumour is assessed as being Stage IV (T3 N2 M1). It is a non-small cell lung cancer, and is an adenocarcinoma. He is tested for EGFR-TK mutation and ALK translocation and the results are negative. His prognosis is poor – only 2% of patients survive 5yrs.
Mr CS is reasonably well (WHO performance status 1) and the Consultant Oncologist offers him chemotherapy with carboplatin, pemetrexed and pembrolizumab (NICE TA 557, Jan 2019).
He is 2m2. The AUC for carboplatin dosing is 5.
His pre-chemotherapy creatinine clearance (formally measured GFR) is 55ml/min.
What doses of carboplatin, pemetrexed and pembrolizumab should Mr CS be prescribed for cycle 1?
What premedications should Mr CS be prescribed and why are these given?
Carboplatin 400mg
Pemetrexed 1000mg
Pembrolizumab 200mg
- Hydroxocobalamin 1mg IM in the week before 1st cycle then every 9 weeks until pemetrexed treatment is complete
- Folic acid 400mg PO od starting at least 1 weak before 1st cycle until 3 weeks after last cycle
These are given to reduce toxicity as pemetrexed is an anti-folate drug
Dexamethasone 4mg PO BD for 3 days starting 24 hrs prior to chemotherapy. This is to reduce incidence & severity of skin reactions to pemetrexed
Prior to the 2nd course of chemotherapy Mr CS’s blood results were as follows:
WCC 3.8 (4-11)
Hb 115 (135-185)
Platelets 75 (150-400) CrCl (calc) 54ml/min
Neuts 2.4 (2.5-7.5)
Should he proceed with chemotherapy? If not why not and what action should be taken by the prescriber?
No, delay for 1 week due to low platelets
What would have happened if his CrCl had dropped to 35ml/min?
Pemetrexed would be contraindicated
What side effects can be experienced by patients on this chemotherapy?
- Myelosuppression
- N&V
- Mucositis, Stomatitis
- Diarrhoea
- Alopecia
- Fatigue
- Rash, skin reactions
What advice could the pharmacist give to a patient about to start on afatinib to help avoid rash/acne?
Avoid alcohol-based emolients
Use aqueous/urea-based moisturisers
Avoid strong sunlight and cover sun-exposed areas
Use SPF30 or above sunblock
Use soap substitues like aqueous cream for bathing
Consider non-biological, no liquid detergents
What would you advise if the patient was having problems swallowing the afatinib tablets?
If patients cannot swallow the tablets they may be dispersed in 100mL non-carbonated water
The tablet should be dropped into the water (not crushed) stirred until it has dispersed into very small particles.
The dispersion should be drunk immediately
Patients should be advised to then rinse the glass in apprx 100ml of water and also consume this
If the patient phoned into the helpline reporting severe erythema, skin peeling (desquamation) and pruritis that had started 10 days ago, what would you recommend?
- Grade 2 rash lasting more than 7 days
: interrupt treatment and reduce dose
: reduce 10mg at a time - Regular emollient
- Clindamycin 1% gel
- Hydrocortisone 2.5% cream
- Oxytetracycline for at least 2 weeks
