(Cancer)

Overview

• Hypercalcaemia occurs in 20-30% of patients with cancer
  • Humoral Hypercalcaemia of Malignancy (80% of cases) → tumour secretion of PTHrP (PTH-related peptide). Occurs in SCC (lung, head and neck), renal cancer, bladder cancer, breast cancer, ovarian cancer.
  • Local Osteolytic Hypercalcaemia → local release of factors by bony metastases that promote osteoclast function. Occurs in multiple myeloma and breast cancer.
  • Calcitriol-Mediated Hypercalcaemia → autonomous production of calcitriol (1,25-dihydroxyvitamin D) due to 1α-hydroxylase activity in tumours cells. Occurs in hodgkin lymphoma and non-hodgkin lymphomas.
• Risk Factors → non-metastatic malignancy (humoral hypercalcaemia), metastatic skeletal involvement (local osteolytic hypercalcaemia), and lymphoma (calcitriol [(1,25-dihydroxyvitamin D)]-mediated hypercalcaemia)

Making Diagnosis

Clinical Features:

• Polyuria & Polydipsia
• Confusion & Fatigue
• Poor Skin Turgor or Dry Mucous Membranes
• Constipation
• Loss of Appetite
• Nausea
• Bone Pain
• Low Mood

<aside> 💡 Hypercalcaemia → stones (renal), bones (bone pain), groans (abdo pain, N&V), thrones (polyuria), psychiatric overtones (confusion, depression, anxiety)

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