Bone metastases

What are bone metastases?

Bone metastases occur when malignant cells from a primary cancer, most commonly breast, prostate, lung, kidney, or thyroid, spread via the bloodstream and colonise bone tissue. The axial skeleton (spine, pelvis, ribs, and skull) is most frequently affected, as these bones have the highest blood flow and red marrow content.

Metastases are classified by their effect on bone:

• Osteolytic: bone is destroyed, creating "holes" in the cortex; most common in lung, kidney, and breast cancer metastases. Increases fracture risk significantly.

• Osteoblastic: abnormal new bone is deposited; characteristic of prostate cancer metastases. Causes bone pain and elevated ALP.

• Mixed: both lytic and blastic features; seen in breast cancer and some others.

Bone is the third most common site of metastatic spread after the lung and liver — making skeletal assessment a critical part of cancer staging and monitoring.

Symptoms of bone metastases

Bone metastases are frequently asymptomatic in early stages, discovered on imaging performed for staging or surveillance. When symptoms occur:

• Persistent, deep bone pain — often worse at night and unrelieved by rest; the most common symptom

• Localised tenderness over the affected bone

• Pathological fracture — fracture with minimal or no trauma from structurally weakened bone

• Spinal cord compression — back pain with neurological symptoms (weakness, numbness, bladder or bowel dysfunction) is a medical emergency

• Hypercalcaemia — from osteolytic bone destruction; causes excessive thirst, confusion, nausea, and constipation

• Fatigue and general malaise in advanced disease

What causes bone metastases?

Bone metastases develop when circulating tumour cells extravasate from blood vessels in bone marrow and establish secondary tumours. The primary cancers most commonly responsible are:

• Breast cancer: the most common cause of bone metastases in women; both osteolytic and osteoblastic patterns

• Prostate cancer: the most common cause in men; predominantly osteoblastic

• Lung cancer: osteolytic; often presenting with pathological fracture

• Kidney (renal cell) cancer: highly osteolytic; prone to causing large, destructive lesions

• Thyroid cancer: particularly follicular type; osteolytic

• Multiple myeloma: a haematological malignancy causing diffuse lytic bone lesions; technically not metastases but clinically similar

How are bone metastases detected?

Detection relies primarily on whole-body imaging, which directly visualises marrow infiltration and cortical destruction, supported by blood tests identifying metabolic consequences of bone involvement.

Full body MRI: MRI is the most sensitive tool for detecting bone metastases, identifying deposits in the marrow long before they appear on X-rays or CT scans. Elfcare’s full body MRI covers the entire axial skeleton, including the brain, spine, pelvis, and ribs, where metastases most frequently occur. This allows us to visualize early marrow infiltration, cortical destruction, and nerve compression. For those with a known primary cancer, these findings are essential for accurate staging and effective treatment planning.

Blood tests identify the metabolic consequences of bone metastases and relevant tumour markers. Relevant markers in Elfcare's panel include:

• ALP (alkaline phosphatase): elevated in certain metastases or when the body attempts to repair bone damage.

• Calcium and albumin-corrected calcium: hypercalcaemia is a classic complication of osteolytic metastases; a medical emergency at high levels

• Phosphate: typically low alongside elevated calcium in metastatic bone disease

• Total PSA: directly relevant for prostate cancer, the most common cause of bone metastases in men

• CRP: elevated in advanced malignancy and associated inflammatory response

• Haemoglobin: anaemia of chronic disease is common with extensive bone marrow involvement

• Vitamin D: supports bone mineralisation; deficiency complicates metabolic management

Why early detection matters

Bone metastases detected before pathological fracture or spinal cord compression allow for systemic treatment of the primary cancer, bone-protecting agents (bisphosphonates, denosumab), and targeted radiation, all of which significantly reduce pain and skeletal complications. Spinal cord compression from undetected vertebral metastases is a neurological emergency with potentially permanent consequences if not identified promptly. A full body MRI that identifies asymptomatic bone marrow changes can initiate a care pathway that prevents these outcomes entirely.

How Elfcare can help

Elfcare's full body MRI images the entire axial skeleton as standard, making it the most powerful tool we offer for bone metastasis detection. Marrow infiltration and early cortical changes are identifiable before fracture or neurological complications develop. For patients with a known primary cancer undergoing surveillance, or for those in whom bone pain prompts investigation, this is a clinically critical examination.

Our blood panel covers calcium, ALP, phosphate, PSA, CRP, and haemoglobin, the key metabolic and tumour markers relevant to bone metastasis assessment.

If our MRI or blood tests identify a suspicious finding, we take care of further diagnostics or refer you to the appropriate specialist.