Evaluation of Recurrence in Patients With Differentiated Thyroid Cancer

Thyroid cancer is the most frequent cancer of the endocrine system, and its incidence is constantly rising worldwide. This is mainly because of advances in examination modalities that have made it possible to detect smaller cancers at an early stage.

Owing to advancements in screening techniques and treatment methods, the number of patients who die from thyroid cancer is small compared to the incidence.[1]

The most common type of thyroid cancer is differentiated thyroid cancer (DTC), which includes papillary and follicular carcinomas. Women are three times more likely to develop thyroid cancer than men. [2] Adjuvant RAI131 (AT) is recommended post thyroidectomy, because of its therapeutic impact on micro-invasions or micro-metastases, to reduce the likelihood of recurrence in patients who do not have metastases but have risk of recurrence according to the Japanese guidelines and American Thyroid Association guidelines [3],[4].

AT could prolong the survival of patients with intermediate-risk DTC [5]. Additionally, a meta-analysis has shown that AT is effective in reducing recurrence in some studies but not in others, and the effect of AT on recurrence prevention, especially in high-risk DTC, remains unclear.[6].

Although there are reliable reports discussing the relationship between the success or failure of remnant ablation [7],[8], recurrence after AT is rarely reported and the number of cases is small. In addition, no study has so far discussed the relationship between the success or failure of AT or remnant ablation and recurrence or death [9],[10].