[Risk groups in differentiated thyroid carcinomas]

Well-differentiated thyroid carcinoma represents 80% of all thyroid malignant tumours, with a survival rate of over 95% at 20 years in 80% of the cases. Although its incidence is increasing, survival remains unchanged. Prognostic factor evaluation allows identifying patients at high or low risk of recurrence, selecting those who will benefit from more aggressive therapy.

We have reviewed the incidence of malignant thyroid neoplasm, selecting them according to three different system definitions (TNM, GAMES, MACIS), as well as by post-surgical complication rate.

Malignant neoplasm represents 28.8% of the thyroid-operated patients, 88% corresponding to well-differentiated carcinomas. 80% are in the low risk group, with similar numbers in all three staging system definitions. Multicentricity was found in 16%, with 50% of the lesions smaller than 2 cm. Permanent recurrent nerve palsy was 1.2% and 2.7% presented permanent postoperative hypocalcaemia.

Risk group percentage is similar to that reported in the literature, with 80% having expected survival over 95% at 20 years. Risk factor evaluation should help to individualise treatment options, avoiding overtreatment and complications in patients that will not benefit from more aggressive therapy.