Prognostic scoring systems in differentiated thyroid carcinoma: which is the best?

The usefulness of three prognostic scoring systems in differentiated thyroid carcinoma (the TNM system, the EORTC score and the AGES index) were evaluated for use in a medium size teaching hospital. Twenty-one patients with papillary (n = 13), mixed (n = 2) and follicular tumours (n = 6) were studied. Median follow-up was over seven years (range 10-194 months). Four patients died. The TNM system gives a poor discrimination between patients with a good prognosis and those with a lethal outcome and is of little value in these tumours. The EORTC score, which is easy to calculate, gives a good prediction of survival. The best discrimination between a good and a bad prognosis was found using the more complicated AGES index for papillary tumours. Of patients with a papillary or mixed papillary carcinoma, one of the two patients with a score of four or more actually died, while all with a good index of less than 4 (13/15 of this subgroup) survived, giving the best prognostic bisection of our patient group. Even in the combined group of all differentiated thyroid carcinomas, the AGES index gives the best prognostic bisection, with 33 percent of patients in the poor prognostic group, of whom 57 percent died. This makes the AGES index the most useful prognostic scoring system.