[Spinal Metastases of Thyroid Origin. Apropos of a Series of 37 Cases]

Purpose Of The Study: Define a specific therapeutic for spinal metastasis from thyroidal origin.

Material: A retrospective series of 37 patients treated between January 1978 and January 1993 was made. The sex ratio was 29 women for 8 men with an average age of 59.5. The prevalent histology has a vesicular type (19 cases which represents 51 per cent). The metastasis are mostly found at the dorsal level (48.6).

Methods: The different parameters analysed for this study of 37 patients were: invaded segment of the vertebra (anterior, middle, posterior or total), Tokuhashi score, epiduritis extent, patient age, histological type and iodiosensibility.

Results: Out of 37 patients, 3 were lost for follow-up, 7 metastasis were treated carcinologically ("en bloc" resection). 30 were treated palliatively depending on the clinical symptoms: neurological, mechanical, or pain. The osseous metastasis exists in 56 per cent of the cases at the time the primitive neoplasy was discovered, and their presence burdens the final prognostic. 21 patients died with an average survival of 21 months, 13 patients survived with a mean follow-up of 50 months, 50 per cent of the patients had a vertebra totally involved with only 13 patients with neurological signs (4 Frankel A, 3 Frankel B, 4 Frankel C and 2 Frankel D).

Discussion: The analysis of the results shows that the pejorative criteria in case of vertebral metastasis of thyroidal cancer are the score of Tokuhashi inferior to 7, the whole affected vertebra, the epiduritis on 3 levels, the age of the patient superior to 65 and the idiosensibility of the metastase. The surgery do called carcinological gives very good results with 5 surviving patients out of 7.

Conclusion: When reading this study it seems that, in front of vertebral metastasis from thyroidal origin, we should choose the most radical therapeutic attitude as much as possible. This strategy finds its justification by the fact that the thyroidal cancer spreads out slowly giving a survivorship superior to 12 months in case of metastatic vertebral affection. The importance of the tumoral reduction is connected with the efficiency of the iodiotherapy (for differentiated histological types). This is a considerable adjuvant treatment for this kind of cancer.