Section 1. Current Treatment Practice for Spinal MetastasesDr Strasser, a radiation oncologist, initiated the presentation with an overview of the manifestation of spinal metastases, stating that these develop in about half of all cancer patients. The median survival after bone metastases is 12 months with prostate cancer and five months with lung cancer, but it is two to three years in patients with breast cancer and multiple myeloma.1–4 Therefore, it is important to address bone metastases in these patients. Treatment is especially important if patients develop fractures and experience pain.
Bone metastases lead to skeletal-related events, including fractures, pain, spinal cord compression, and hypercalcemia. Spinal metastases can be classified as osteolytic or osteoblastic; radiosensitive or radioresistant; or by spinal cord location. Osteoblastic vertebral lesions, which are common in patients with prostate cancer, are characterized by increased bone density and decreased bone stiffness. Osteolytic bone lesions, which are common in patients with multiple myeloma, are characterized by decreased bone density, bone stiffness, and bone strength. Patients with osteolytic lesions have a higher risk of fractures.
When managing patients with spinal metastases, it is important to consider neurological aspects (e.g., degree of epidural cord compression, myelopathy, or radiculopathy), oncological aspects (e.g., tumor histology, radiosensitivity, and prognosis), mechanical instability, systemic disease, and patient preference for treatment.
Treatment goals are generally achieved by using a combination of complementary systemic and local therapies. Systemic therapy is used to improve patient survival, slow the progression of the disease, and prevent future events. Systemic therapy options for spinal metastases include steroids, bisphosphonates, chemotherapy, hormonal agents, and radiopharmaceuticals. Local therapies include surgery (e.g., spine stabilization) and radiation. Local therapy is used to control pain, restore anatomy, ablate a systemic tumor, and stabilize a fracture.
Reasons for performing open surgery for spinal metastases include tissue confirmation, pain relief, spine stabilization, anterior decompression, and neurologic decompression. Open surgery is a major procedure—patients need a prolonged rehabilitation (four to six weeks of recovery)—and it may not be suitable for some of them. Surgery can decompress nerves and restore anatomy, but it generally cannot treat the tumor.
Reasons for using conventional radiation to treat patients with bone metastases are that radiation treats the tumor, provides local pain control, delays or prevents local progression, and is relatively non-invasive. Problems with radiation therapy are that compression fractures are still possible after radiation; the bone is weakened; radiation is myelosuppressive; and it does not stabilize the fracture.