Endocrine Abstracts

Introduction, material and methods: Papillary thyroid cancer is well known to be a tumour with a good prognosis; in spite of that, it usually presents many recurrences that increases its morbidity. Follicular thyroid cancer is less frequent but has a higher rate of hematogenous dissemination and higher mortality than papillary thyroid cancer. We have collected the data of our patients with differentiated thyroid cancer during the period from 2000 to 2015. In this study, we have described the clinical and follow-up aspects of these patients and compared them depending if the patient was affected of papillary or follicular thyroid cancer. Clinical differences were measured trough odds ratio (OR) when possible. Statistical differences were measured through OR’s confidence interval when possible, and Fisher’s exact proof when OR was not possible. Papillary thyroid cancer was considered the category of reference. Statistical analysis of the data was made with Stata IC 14.2.

Results: A total amount of 87 valid cases of thyroid cancer were diagnosed during the period from 2000 to 2015. From the total amount of the cases, 80(91,95%) were papillary thyroid cancer and 7(8,05%) were follicular thyroid cancer. Comparing the follicular cases with the papillary, there were clinical and statistically significant differences in distant metastasis at the moment of diagnosis [OR 18.5 (CI 95% 1.74-176.8). There were also statistically significant differences in AJC7 classification (Fisher’s exact =0.002), ATA risk classification (Fisher’s exact=0.006), number of radioiodine sessions (Fisher’s exact=0.031) and death because of thyroid cancer (Fisher’s exact=0.006). There were no statistically significant differences in the rest of categories analysed: age, sex; multifocality, lymphadenopathies or extrathyroidal involvement in the moment of diagnosis; treatment with radioiodine and presence of antithyroglobulin antibodies.

Conclusions: We can confirm that patients affected of follicular thyroid cancer are more aggressive in the moment of diagnosis and have worse prognosis during the follow up with higher risk of death. We recognize two main limitations in this study: the first would be the few cases of follicular thyroid cancer in our data that can subtract power from the study; the second one would be that our study is a raw analysis and there may be confounding factors that interfere with the results of our study.