Multiple myeloma and back pain: a blood cancer that affects the bones
Age over 60 with persistent unexplained back pain • Unexplained fatigue or anaemia • Recurrent infections • Unexplained weight loss • Bone pain in multiple sites simultaneously • Raised calcium symptoms: excessive thirst, confusion, constipation.
What is multiple myeloma?
Multiple myeloma is a cancer of plasma cells — the white blood cells that produce antibodies. Abnormal plasma cells accumulate in the bone marrow and produce substances that dissolve bone, causing the characteristic lytic lesions (holes in bone) seen on imaging. The spine is one of the most commonly affected sites, making back pain a frequent presenting symptom.
Myeloma is most common in adults over 60. It accounts for approximately 1% of all cancers but around 10% of blood cancers. It is treatable but not currently curable, though outcomes have improved significantly with newer therapies including proteasome inhibitors and immunomodulatory drugs.
How myeloma causes back pain
Myeloma cells in the vertebral bone marrow secrete substances that dissolve bone. The result is progressive bone destruction producing lytic lesions that weaken vertebrae and can cause pathological fractures — similar in appearance to osteoporotic compression fractures but with a different underlying mechanism and requiring different treatment.
Symptoms
- Back and rib pain — often constant, present at rest and at night
- Fatigue and anaemia — from displacement of normal bone marrow
- Recurrent infections, particularly pneumonia — from impaired antibody production
- Hypercalcaemia symptoms: excessive thirst, confusion, constipation, nausea
- Kidney problems from abnormal protein deposits
- Height loss from vertebral compression fractures
Myeloma is diagnosed through blood tests (protein electrophoresis showing a paraprotein, full blood count, calcium, kidney function), urine tests (Bence Jones protein), bone marrow biopsy, and skeletal survey imaging. A serum protein electrophoresis is a simple and sensitive screening test that any GP can request.