The spine is a frequent site affected by tumors and cancers both arising in the spine and those spreading from other sites in the body. The tumors that commonly affect the spine are Osteoid osteoma, Osteoblastoma, Aneurysmal Bone Cyst, Giant cell tumor, Eosinophilic granuloma, lymphoma and Plasmacytoma. The cancers that commonly affect the spine primarily are Multiple Myeloma, Leukemia, Ewing’s Sarcoma, Osteosarcoma and Chondrosarcoma.
The cancers that spread to the spine (metastasis) from other sites in the body are prostrate cancer, breast cancer, lung cancer, thyroid cancer and renal cancer. Of these, prostrate cancer and breast cancer metastasis are bone forming (osteoblastic or osteosclerotic) whereas the other cancers are bone destroying (osteolytic).
These patients can present with pain (especially at night or at rest), weight loss, loss of appetite and fever. Some patients can present with weakness, numbness, paralysis or alteration in urine and motion pattern due to involvement of the spinal cord from the tumor / cancer. The most important aspect with spinal lesions is to make the correct diagnosis regarding the origin of the tumor. X-rays and MRI (usually with Contrast) form the mainstay of radiological imaging for spinal tumors and cancers. CT can be very useful to diagnose some tumors like Osteoid Osteoma.
Bone Scan is the best investigation to study the spread of cancer from other sites (metastasis) to the bones including spine. In quite a few spine lesions, we are unable to pin point as to what is the primary source of the cancer. PET-CT is the ideal test in such a scenario to identify the hidden primary focus of cancer. Frequently, all of these investigations may not tell us what the primary source is. In such cases, a biopsy from the spine is required to reach the diagnosis.
Lesions of the spine such as Osteoid osteoma, Osteoblastoma, Aneurysmal Bone Cyst, Giant cell tumor and Chondrosarcoma always need surgery. For primary and secondary cancers (metastasis) of the spine, chemotherapy and radiotherapy form the mainstay of treatment. Surgery is required for:
- Obtaining material for biopsy in case of unknown lesions.
- Relieving pressure on the spinal cord
- Intractable pain
- Severe destruction of spinal bones
Frequently, surgery is preceded by a CT guided embolization (of blood vessels supplying the tumor) to decrease blood loss during surgery. The spine surgery in these cases involves decompression of nerves, removal of tumor, sending material for biopsy, reconstructing the defect left behind after removing the tumor and fixing the spine with screws and rods made up of titanium.
Some cases with intractable metastasis related pain might be suitable for cement injection procedures (Kyphoplasty / Vertebroplasty). This percutaneous procedure is particularly suitable for these patients with multiple medical co-morbidities as general anesthesia; open surgery and blood loss can be avoided. The procedure involves injecting cement in the spinal bone under the guidance of an X-ray. The injected cement gives immediate structural support to the spinal bone involved by the cancer, thereby relieving pain.