Complications: Hypercalcaemia

Question 1

What is the normal corrected calcium range?

Answer 1

2.2-2.6

Question 2

In what type of cancer is hypercalcaemia most common?

Answer 2

Squamous cell cancers 
Lung 
Head and neck
Kidney 
Cervix

Question 3

What causes hypercalcaemia associated with malignancy?

Answer 3

• paraneoplastic syndrome: tumour secreting PTHrP - increases bone resorption and renal reabsorption
• osteolytic metastasis: bone destruction causing calcium release
• tumour production of vitamin D in lymphoma: increases intestinal calcium absorption

Question 4

What symptoms are associated with hypercalcaemia associated with malignancy?

Answer 4

Nausea
Polydipsia and polyuria 
Confusion 
Constipation 
Poor concentration 
Weakness 

In cancer associated hypercalcaemia, pateints do not tend to get stones (bones, stones, groans, moans)

Question 5

How is it managed?

Answer 5

Rehydrate with fluids
Bisphosphonates e.g zolendronic acid - take approx 1 week to work
Denosumab SC for refractory hypercalcaemia

Question 6

In what percentage of cancer patients does it occur?

Answer 6

10-20%

Question 7

What tumours release PTHrP?

Answer 7

Breast cancer
Squamous cell lung cancer
Squamous tumours of H&N

Question 8

How does PTHrP increase bone resorption?

Answer 8

It increases osteoclast activity

Question 9

What are the most common tumours to cause bone metastases?

Answer 9

Prostate - tends to be osteoblastic not osteolytic
Lung
Breast

Question 10

How do bisphosphonates work?

Answer 10

Encourage osteoclasts to undergo apoptosis - slowing bone loss

Question 11

What side effects are associated with bisphosphonates?

Answer 11

Fever, flu like symptoms
Oesophageal irritation, stomach inflammation
Nausea
Jaw necrosis - especially mandible (most cases occurring after IV high dose administration)

Can cause renal failure, so rehydrate first