Introduction: Differentiated thyroid cancer (DTC) is one of the most frequent forms of malignancy. Because of its favourable outcome and low mortality rates, identifying prognostic factors has been a challenge. Several risk stratification systems have been developed. Most of them include demographic and tumour specific features, as well as extrathyroidal extension. Our objective was to compare clinical characteristics between DTC patients with and without remission.
Methods: Data from patients followed for DTC between 1956 and 2016 was retrieved. Patients with less than 2 years of follow up, those submitted to subtotal thyroidectomy or with positive antithyroglobulin antibodies were excluded. They were divided in two groups, according to the presence or absence of remission criteria (undetectable TSH-suppressed thyroglobulin levels and no evidence of structural disease). Groups were compared for age at diagnosis, nodule dimensions, multicentricity, capsule presence and extrathyroidal involvement as well as the presence of node or distant metastasis.
Results: A total of 814 patients was included, 82.9% of which were female. The median age at diagnosis was 47 years old (min. 11; max. 89). Five hundred patients had criteria for remission (Group 1) and 314 didnt (Group 2 [36 with cancer related death, 55 with persistent or recurrent disease and 223 with indeterminate response]). Median follow up was 10 years (min. 3; max. 50) in Group 1and 9 years (min. 3; max. 57) in Group 2. Patients in group 1 were significantly younger (median 44.5 vs 49.5; P<0.001) had more multicentricity (45,7% vs 37.7%; P=0,041) and less local (22.7 vs 30.6%; P=0,016) and distant metastasis (0.4% vs 5.7%; P<0,001). No differences were found in nodule dimensions, capsule presence or extrathyroidal involvement.
Conclusion: Among patients with differentiated thyroid cancer, the older ones, with unicentric tumours, local or distant metastasis at presentation seem to have worst outcome.
20 - 23 May 2017
European Society of Endocrinology