Spinal Cord Metastases
Spinal cord metastases refer to cancer that has spread from its original site to the spinal column or spinal cord. This is a serious complication of advanced cancer, occurring when malignant cells travel through the bloodstream or lymphatic system to the spine. Metastases most commonly affect the vertebral bones, but can also involve the epidural space (around the spinal cord), and rarely, the spinal cord itself. Common primary cancers that metastasize to the spine include lung, breast, prostate, kidney, and multiple myeloma. Early detection and treatment are critical to prevent or minimize neurological damage.
What is it?
The spine is one of the most common sites for metastatic cancer due to its rich blood supply via the vertebral venous plexus—a network of valveless veins that allows tumor cells to spread easily from primary sites. Spinal metastases are classified by location: vertebral body metastases (most common) involve the bones of the spine; epidural metastases occur in the space surrounding the spinal cord and nerve roots, often resulting from extension of vertebral metastases; intradural-extramedullary metastases are rare and located within the dural sac but outside the spinal cord; and intramedullary metastases (rarest) involve the spinal cord tissue itself. The thoracic spine is most frequently affected, followed by the lumbar and cervical regions.
Cancer cells reach the spine through several mechanisms: hematogenous spread via arterial blood flow or retrograde venous spread through Batson’s plexus; direct extension from nearby tumors (such as lung or esophageal cancers growing into the spine); and rarely, CSF seeding in cases of leptomeningeal metastases. The most common primary cancers that metastasize to the spine include lung cancer (most frequent), breast cancer, prostate cancer, renal cell carcinoma, melanoma, thyroid cancer, and multiple myeloma. The metastatic deposits can cause problems through several mechanisms: direct compression of the spinal cord or nerve roots (epidural spinal cord compression); pathologic fractures when tumor weakens bone structure; mechanical instability of the spine; and bone pain from periosteal stretching and inflammatory mediators. Epidural spinal cord compression is an oncologic emergency requiring urgent treatment to prevent permanent paralysis.
Important to Know
Back pain is the most common initial symptom, occurring in over 90% of patients with spinal metastases. The pain is typically progressive, worse at night or with lying down (unlike mechanical back pain which improves with rest), and may be localized to the spine or radiate along nerve pathways. Other symptoms depend on the degree of spinal cord or nerve root compression and include progressive weakness in the legs (lower extremity weakness with thoracic/lumbar metastases, or arm/leg weakness with cervical metastases), sensory changes such as numbness, tingling, or loss of sensation below the level of compression, gait disturbances and difficulty walking, and bowel or bladder dysfunction (urinary retention or incontinence, constipation) which indicates severe compression requiring emergency intervention. Diagnosis requires urgent MRI of the entire spine with gadolinium contrast, which is the gold standard for detecting metastases and assessing spinal cord compression. CT can show bony destruction, and bone scans or PET-CT help identify multiple sites of metastatic disease. Treatment is multidisciplinary and depends on several factors including the number and location of metastases, degree of spinal cord compression, spinal stability, patient’s overall prognosis, and the primary cancer type. High-dose corticosteroids (dexamethasone) are given immediately to reduce spinal cord edema. Radiation therapy is the primary treatment for most spinal metastases, providing pain relief and local tumor control. Surgery (decompressive laminectomy with or without spinal stabilization) is considered for patients with spinal instability, progressive neurological deficits despite radiation, need for tissue diagnosis, or radiation-resistant tumors. Systemic treatments including chemotherapy, hormone therapy, immunotherapy, or targeted therapies address the underlying cancer. Prognosis varies widely based on primary cancer type, extent of metastatic disease, neurological status at presentation, and response to treatment. Early detection and treatment before severe neurological deficits develop offer the best chance for maintaining function and quality of life.