Metastatic spine cancer occurs when cancer cells from another part of the body spread to the spine or spinal cord. This secondary malignancy commonly originates from breast, lung, prostate, kidney, or thyroid cancers. Tumors in the spine can compromise vertebrae, facet joints, pedicles, or occasionally the spinal cord itself, leading to pain, neurological deficits, and significant reduction in quality of life.
Understanding the Pathology and Location of Spine Metastases
Metastatic spine lesions can be classified by their effect on bone and soft tissue:
Osteolytic lesions: Cause bone destruction and collapse, commonly from lung, kidney, and thyroid cancers.
Osteoblastic lesions: Lead to increased bone density, typical in prostate cancer metastases.
Mixed lesions: Display both bone destruction and abnormal bone formation, often seen in breast cancer.
Compression fractures: Occur when vertebral bodies weaken and collapse.
Epidural invasion: Tumor extends into the spinal canal, pressing on the spinal cord or nerve roots.
Common locations of metastasis
Thoracic spine (middle back): Most frequently affected (60–70%).
Lumbar spine (lower back): Involved in 20–30% of cases; can cause lower extremity weakness and neurogenic claudication.
Cervical spine (neck region): Rare (~10%), often associated with upper extremity symptoms and neck pain.
Recognizing the Symptoms
Symptoms vary depending on tumor location and degree of spinal cord or nerve root compression:
Persistent and severe back or neck pain, often worsening at night.
Muscle weakness or limited mobility.
Numbness, tingling, or sensory deficits in arms, legs, or trunk
Neurogenic claudication: Pain and weakness in the legs during walking, relieved by sitting or bending forward.
Bladder and bowel control problems.
Spinal deformities or pathological fractures.
Diagnosis: Step-by-Step Evaluation
Accurate diagnosis requires thorough clinical assessment and advanced imaging.
Physical Examination and Neurological Assessment: Muscle strength, reflexes, and sensory function are evaluated.
Balance and gait testing.
Pain characterization and duration are carefully documented.
Laboratory Testing: Serum calcium and alkaline phosphatase levels to detect bone turnover
Complete blood count to evaluate overall health and cancer activity
Imaging Studies: X-rays: Identify vertebral collapse, structural changes, and alignment issues.
Magnetic Resonance Imaging (MRI): Detects spinal cord compression, epidural tumor spread, and nerve root involvement. T1- and T2-weighted sequences provide detailed information.
Computed Tomography (CT) scans: Offer precise bone detail and vertebral anatomy assessment.
Positron Emission Tomography (PET): Evaluates systemic tumor spread and identifies active metastatic sites.
Biopsy (Fine Needle Aspiration or Surgical Biopsy): Confirms tumor type and primary origin.
Treatment Options
Management focuses on pain control, maintaining spinal stability, preserving neurological function, and improving quality of life.
1. Chemotherapy
Chemotherapy uses medications to target and destroy cancer cells in the spine and throughout the body. It can be administered intravenously or orally. In some cases, chemotherapy is given before surgery—called neoadjuvant therapy—to shrink tumors and facilitate safer surgical intervention. Chemotherapy also helps reduce tumor burden and alleviate pressure on spinal structures.
2. Radiation Therapy
Radiation therapy employs high-energy X-rays to destroy cancer cells or shrink tumors. It is particularly recommended for patients with isolated spinal lesions. Shrinking the tumor reduces spinal cord and nerve root compression, which alleviates pain. Modern techniques minimize radiation exposure to healthy surrounding tissues.
3. Stereotactic Radiosurgery
This non-invasive procedure delivers highly focused, precise radiation beams to the tumor while sparing healthy tissue. Stereotactic radiosurgery is often used for limited spinal metastases and offers effective tumor control.
4. Surgical Intervention
Surgery is generally considered when chemotherapy and radiation therapy fail to adequately manage symptoms. Surgical goals include relieving spinal cord or nerve root compression, stabilizing the spine, and preventing further vertebral collapse.
Surgical Procedures
Vertebroplasty
Injection of bone cement stabilizes vertebral compression fractures and reduces pain.
Kyphoplasty
A balloon elevates the collapsed vertebra before cement injection to restore height and alignment.
Decompression Surgery
Laminectomy or laminotomy removes tumor tissue compressing the spinal cord.
Foraminotomy widens nerve root exit canals to relieve pressure.
Stabilization and Spinal Fusion
Rods and screws are used to stabilize affected vertebrae.
Multi-level fusions correct deformities and ensure structural stability.
Multidisciplinary Approach
Optimal management combines chemotherapy, radiation, surgery, and supportive care, tailored to tumor type, patient health, and lesion location. Palliative care plays a crucial role in managing pain and improving quality of life.
Prognosis
Metastatic spine cancer is an advanced stage of malignancy. Prognosis depends on:
Type and aggressiveness of the primary cancer
Extent of metastasis and spinal cord involvement
Response to treatment
Early diagnosis, prompt multidisciplinary care, and targeted interventions can significantly enhance functional outcomes and patient quality of life.