Endocrine Abstracts

Objectives: The majority of patients with differentiated thyroid carcinoma (TC) have an excellent prognosis, with a 5-year survival rate of 98.3%, and only rarely reaches an advanced stage of disease. The present study aims to identify the clinicopathological and epidemiological features at the time of diagnosis of a group of patients who required to be treated with systemic therapy with tyrosine-kinase inhibitors (TKI).

Methods: We retrospectively evaluated 136 patients with thyroid carcinoma who were addressed to TKI between 2012 and 2022 and followed at the Endocrine Unit of the University Hospital of Pisa. Demographic, clinical and pathological data were collected at the moment of the initial diagnosis and at the moment the systemic therapy was started.

Results: Sex distribution was equal: 69 females (50.7%) and 67 males (49.3%). The mean age was advanced both at diagnosis (59.01±10.44 years) and when systemic therapy was started (68.85±8.52 years). The histotypes (available in 135 cases) were distributed as follows: 72 papillary thyroid carcinomas (PTC) (53.8%), 27 follicular TC (20.1%), 29 poorly differentiated TC (21.6%), 6 Hürthle cell TC (4.5%). The histological variants of PTC (available in 51 cases) were: 21/51 classical (41.2%), 14/51 tall cell (27.5%), 15/51 follicular (29.4%), 1/51 solid (1.9%). The histological variants of FTC (available in 16 cases) were: 6/16 widely invasive (37.5%), 4/16 minimally invasive (25%), 6/16 oxyphil (37.5%). Regarding TNM classification, primary tumors were frequently classified as T3 and T4 (40.4% and 30.3%, respectively). At initial diagnosis 73/136 patients (55.3%) presented with lymph node metastasis (LNM) and 51/136 patients (39.8%) with distant metastasis (DM). At the moment of starting systemic therapy, 114/136 patients (84.4%) had LNM and 126/136 patients (92.6%) had DM. AJCC stage at diagnosis (available in 120 cases) was distributed as follows: 31/120 at I stage (25.8%), 25/120 at II stage (20.8%), 15/120 at III stage (12.5%), 10/120 at IVA stage (8.3%), 39/120 at IVB (32.6%). At TKI inception 120/136 patients (88.2%) were at stage IVB, 7/136 patients at stage IVA (5.1%), 2/136 patients at stage III (1.6%) and 7/136 patients at stage II (5.1%).

Conclusions: Male sex, advanced age, lymph node and distant metastases at the time of diagnosis are the most relevant features associated to the need of starting systemic therapy with TKI.