Case of the Month #26: Myeloma Pain by Dr Sonia Pierce

Multiple Myeloma is a haematological malignancy characterised by infiltration of the bone marrow by plasma cells. It can be associated with lytic bone disease causing severe bone pain, pathological fractures, and neurological compromise. It is the second most common haematological malignancy in Europe, with an estimated age-standardised incidence of 9.6 per 100 000 people in the UK for the year 2017, projected to increase to 12 per 100 000 people by 20351, 2. Many of the presenting symptoms are non-specific and patients with myeloma have one of the longest time-to-diagnosis intervals among cancers, with an average time between symptom onset and diagnosis of 99 days3,4.

Multiple Myeloma causes disabling complications including skeletal-related conditions (destructive lytic lesions, osteoporosis and hypercalcaemia), renal impairment, infection, neurological complications and anaemia1,5. The acronym "CRAB" is sometimes used to remember myeloma-defining events that are used in the diagnosis: calcium elevation, renal insufficiency, anaemia and bone disease. The International Myeloma Working Group recommends a series of laboratory and imaging investigations to evaluate patients with a suspected diagnosis of Multiple Myeloma, to assess for these features (e.g., haemoglobin, calcium levels, kidney function, paraprotein and light chains)1. Back pain combined with other symptoms such as fatigue and weight loss, or back pain combined with abnormal blood tests warrant definitive investigation for Multiple Myeloma6.

Multiple Myeloma related pain typically involves the central skeleton (back, neck, shoulders, pelvis, hip), rather than the extremities. Pain is often induced by movement and is less common at night during sleep, though can occur with change of position and is usually mild or moderate in intensity but is severe in up to 10 percent. Focal or diffuse spinal osteolysis may result in significant morbidity by causing painful progressive vertebral compression fractures and deformities7. Risk factors for Multiple Myeloma include age (average age of diagnosis is 69), race, sex (men are at a 1.5× risk), and family history. Diagnosis includes serum or urine electrophoresis and free light-chain assay but requires bone marrow biopsy. It is distinguished from smouldering myeloma and monoclonal gammopathy of undetermined significance by a high (>3 g/dL) level of M-protein (monoclonal light chains) and the presence of CRAB (Hypercalcemia, Renal failure, Anaemia, Bone pain) symptoms8.  

Although Multiple Myeloma remains a largely incurable condition, the introduction of novel therapies has significantly improved clinical outcomes. For many patients, Multiple Myeloma is a long-term chronic condition with a remitting and relapsing course9. The survival has more than doubled over the past decades due to the introduction of new chemotherapy combinations, targeted small molecule inhibitors and monoclonal antibodies, autologous stem cell transplantation and enhanced supportive care8,9. In those patients fit enough to be considered for transplant, induction chemotherapy is administered prior to stem cell collection to reduce the number of tumour cells in the bone marrow and peripheral blood, lessen symptoms, and reverse end-organ damage.

For details on current treatment approaches and further reading, please see the references below and the “Recommending reading for April 2023” section of FPMLearning.