vertebral tumors

BACKGROUND

Tumors involving the vertebra (spinal bones) are rare in cats and dogs. Osteosarcoma is the most common vertebral tumor, but other malignant tumors include chondrosarcoma, fibrosarcoma, and multiple myeloma, while benign tumors such as osteochondroma have also been reported. The vertebrae are also a relatively common site for metastasis from other sarcomas and carcinomas. The greatest challenge in treating primary vertebral tumors is preventing local tumor recurrence, but metastasis has occasionally been reported.

DIAGNOSIS

Survey or contrast (myelogram) radiographs may be sufficient for the diagnosis of vertebral tumors, but advanced imaging (CT or MRI scans) is preferred to determine tumor location, the extent of the tumor, and possibly plan the surgical procedure. Biopsy is rarely necessary as treatment options are not changed by a knowledge of the tumor type.

CLINICAL STAGING

Thoracic radiographs or CT scans are recommended to assess the lungs for metastasis.

TREATMENT

Treatment options for control of the local tumor include surgery and radiation therapy. The feasibility of surgical excision depends on tumor location and size. The combination of surgery and radiation therapy is recommended in people with vertebral tumors and we have had good success with this combination in dogs. Chemotherapy should also be considered for dogs with osteosarcoma and multiple myeloma.

PROGNOSIS

The prognosis for dogs with vertebral tumors is guarded. Recurrence or regrowth of the tumor causing a repeat of pain and neurologic signs is the most common reason for euthanasia. The overall median survival time of 20 dogs for treated vertebral tumors was 135 days and was significantly improved in dogs with good neurologic function before and after surgery and when radiation therapy was combined with surgery. The median survival times for dogs treated with surgery alone and surgery and radiation therapy were 38 days and 135 days, respectively. Dogs with pain only as a result of their vertebral tumor had a median survival time of 330 days, which was significantly longer than the  median survival time of 120 days for dogs with neurologic signs ranging from weakness to paralysis. Following surgery, eight dogs improved neurologically, seven dogs remained the same, and five dogs deteriorated neurologically. Dogs with either postoperative pain and/or weakness (median survival time 135 days) were 12-times more likely to survive than dogs with postoperative ataxia or paralysis (median survival time 15 days).

Last updated on 6th March 2017