Postoperative thyroglobulin level determination to follow up patients with highly differentiated thyroid cancer

The highly differentiated thyroid tumours account for 0.80% of all human malignancies. The papillary and follicular tumour tissues of this tumour type are relatively benign, hormone-dependent and beside their treatment specificity they secrete the tumour-specific thyroglobulin. This it becomes possible to follow the development of metastases, the effectiveness of therapy applied as well as the history of the disease. The authors studied the change of thyroglobulin level in 153 patients with highly differentiated thyroid cancer. In 29 of 32 metastatic patients a pathologically elevated (70-100 ng/ml) thyroglobulin level was observed. This proves the 91% specificity of the method in verified metastatic tumours. Compared to the total body scintigraphy 3 false-negative and 6 false-positive cases were found. The authors establish that, irrespective of the site of metastasis, the thyroglobulin level is higher in the follicular than in the papillary subtype. It is concluded that the measurement of the serum thyroglobulin level is a suitable marker of the highly differentiated thyroid cancer since it indicates local recurrence or distant metastases by a significant increase while therapy-resultant tumour diminution is accompanied by a marked decrease.