Thyroid cancer is relatively common, and in most patients can be treated effectively. A number of patients, however, have recurrent tumours, and there is a current lack of genetic clues as to the likelihood of this happening. Recently, a new gene has been discovered to be important in pituitary, colon and other tumours. Pituitary tumor transforming gene (PTTG) works by attaching itself to a binding protein called PBF, and then stimulating the expression of another gene called fibroblast growth factor 2 (FGF-2). FGF-2 has previously been linked with the growth of thyroid tumours.
We have now shown that PTTG and FGF-2 are unusually high in thyroid cancer,
but less so in multinodular goitres or Graves' disease. In addition, increased
FGF-2 levels were associated with lymph node invasion and metastasis - two indicators
of tumour severity. High PTTG expression was also associated with the likelihood
of tumours recurring. Overall, therefore, our findings suggest that PTTG and
FGF-2 expression are good potential prognostic factors which may predict the
progression of thyroid cancers, but play less important roles in Graves' disease
and multinodular goitres.