Spinal lesions occur in 50% of patients with osseous metastasis.16 Of these, almost 10% of patients develop malignant spinal cord compression (MSCC).16,17 Hematologic spread is the most common mechanism of spinal cord involvement. Metastatic solid tumors of the lung, breast, and prostate cancer are the most common malignancies associated with MSCC.18 Non-Hodgkin's lymphoma, multiple myeloma, renal cancer, sarcomas, and unknown primary tumors are less common causes.18,19
Early recognition of MSCC is vital because restoration of neurologic function and prognosis is directly related to the degree of initial neurologic damage.17,19 Pain is the first symptom in 83% to 90% of cases and studies suggest that 60% of cancer patients complaining of back pain have compression of the epidural space.18,20,21 Thus, in the setting of metastatic disease and back pain, there should be a high suspicion for MSCC. Motor deficits, ranging from weakness to paralysis, are present in 35% to 68% of cases.17,20 Sensory deficits are usually not recognized by the patients but are present on physical exam in 70% of cases.20 Autonomic dysfunction and loss of sphincter tone is a poor prognostic factor for recovery as this presents late in the progression of the disease.17,18,20
The gold standard and most cost-effective method for diagnosis of MSCC is MRI.18 Metastatic lesions to the spine are usually widespread, therefore, a whole spine MRI should be performed in all patients with suspected MSCC.18 Angiography is useful for hypervascular tumors (sarcoma, melanoma, thyroid, and renal cancer) in which presurgical embolization can be considered.19,21
Prognosis after MSCC is poor and survival after diagnosis of MSCC is usually 3 to 6 months.16,17 The goal of treatment is to decrease pain and preserve neurologic function; therefore, a high suspicion and early recognition is important to improve outcomes.18,19 Scoring systems that include functional status, type of tumor, number of bone and visceral metastases, degree of neurologic dysfunction, and response to radiotherapy are intended to evaluate prognosis and guide therapy.17,18 Due to the wide variety of available scores, it is important that treatment is guided by a multidisciplinary team that can assess risks and benefits in an individual manner.
First-line treatment of MSCC are corticosteroids as they have been shown to reduce pain and improve neurologic function.22 Corticosteroids should be administered promptly to decrease spinal cord edema and in some cases, such as lymphoma, to reduce tumor burden.18 Administration should be prior to radiotherapy, for a total of 10 days, and low doses seem to be as efficacious as megadoses.22
Radiation therapy is also widely used for the treatment of MSCC. It is recommended for patients who are unable to tolerate surgical procedures, have a short life expectancy, have diffuse spinal disease, symptoms present for longer than 48 hours, or those with a known tumor sensitivity to radiotherapy.17,20 This mode of treatment is known to reduce pain, tumor size, and preserve neurologic function.17
Surgical decompression is indicated in patients with progression of tumor and symptoms while undergoing radiation, significant cord compression, medically intractable pain, radioresistant tumors, and evidence of spinal instability.20 Published meta-analysis and randomized controlled trials (RCTs) have shown that surgical intervention in combination with radiotherapy improves neurologic function, pain control, and survival when compared to radiation alone.16,18,21 Despite these encouraging results, it is important to take into account the patient's overall status and prognosis before undergoing any surgical procedure.17,18
Spinal stereotactic radiosurgery, percutaneous vertebroplasty, and kyphoplasty are being considered as more localized and less invasive methods of treatment of MSCC. Although some studies have shown promising results, they are still not widely used and are still considered experimental.18,19,21
Overall, MSCC should be readily recognized in the oncologic population. Management and diagnosis should be immediate, multidisciplinary, and tailored to every patient's diagnosis and overall prognosis.