Pattern of prostate cancer metastasis to the vertebral column.

We examined 34 thoracic and lumbar vertebrae in eight patients with prostate cancer to elucidate the pattern of metastasis to the vertebral column. Computed tomography of thoracic and lumbar vertebrae was performed before treatment for the prostate cancer. Metastatic lesions were confirmed both by the recognition of osteoblastic and/or osteolytic lesions on CT and by histological identification at autopsy. Localized metastatic lesions were observed mostly in the peripheral rather than the central part of the vertebral body. There were no differences in distribution of lesions between the anterior and posterior parts of the vertebral body. There was no primary involvement of tumor in the spinous and transverse processes. These findings indicated that the major metastatic pathway to the vertebral column is via the vertebral venous system, and it appears that prostate cancer cells first metastasize to the vertebral body and then spread secondarily to the processes or other vertebrae.