Endocrine Abstracts

Introduction

Thyroid cancer is the most common endocrine malignancy and its overall incidence has increased significantly in the last 30 years. Cancer in adolescents and young adults (AYA) is defined by the National Cancer Institute as diagnoses occurring among those aged 15 to 39 years. Thyroid cancer is the second most common cancer in the AYA population. In this study, we aimed to compare clinical, ultrasonographical, cytological and histopathological features of thyroid carcinoma in patients AYA with older counterparts.

Materials and methods

The medical records of patients who underwent thyroidectomy between December 2006 and September 2016 and were diagnosed with thyroid cancer histopathologically were retrospectively reviewed. Patients were subdivided into two age groups: 15–39 (Group1 ) and ≥ 40 years old (Group 2). Thyroid functions, ultrasonographic features of malignant nodules, cytological and histopathological findings were compared in patients with AYA patients and ≥ 40 years.

Results

The study included 229 (22.6%) AYA patients and 784 (77.4%) patients aged ≥ 40 years. Thyroid functions, thyroid autoantibody positivity and thyroidectomy indications were similar. There were 305 (21.4%) and 1121 (78.6%) malignant foci in Group 1 and 2, respectively. Preoperative US features were similar in the two groups. Cytological results were distributed similarly in two groups (P = 0.512). Of all cancer types, 93.1% in Group 1 and 93.5% in Group 2 were papillary thyroid cancer (P = 0.772). Follicular cancer was found in 2.6% of Group 1 and 2.1% of Group 2 (P = 0.544). Medullary cancer constituted 1% of Group 1 and 1.1% of Group 2 (P = 0.895). Anaplastic cancer was found in 0.4% of Group 1 and 0.4% of Group 2 (P = 0.940). Lymph node metastasis was detected in 9.2% of group 1 and 7.4% of group 2 (P = 0.246). Distant metastasis was not detected in group 1, and it was found in 3 (0.4%) patients in group 2 (P = 0.366). There was not any significant difference in capsular and vascular invasion and extracapsular extension between groups.

Conclusion

Previous studies have found that although AYA patients are more likely to be diagnosed with locoregional lymph node involvement compared to older patients, they are less likely to be diagnosed with distant metastases. In our study, the rate of diagnosis of lymph node metastasis was higher and the rate of distant metastasis was lower, but the difference was not statistically significant.