Endocrine Abstracts

In recent years, an increasing interest in an individualized approach for the care of patients with differentiated thyroid cancer has occurred. The cornerstone of individualized treatment is the existence of a proper risk stratification system that supports physicians’ options regarding the treatment and follow-up of patients. Considering that the initial risk stratification systems account for only about 15–20% of the variability in the outcome they are trying to predict, it is now well recognized that risk stratification is a dynamic process. The input of clinical, biochemical and imaging data collected during follow-up, notably the response to the initial treatment, can dramatically change risk estimation and significantly improve its accuracy in predicting long-term outcomes. The use of this approach faces different problems in patients with low/intermediate risk and in patients with high risk of recurrence. Regarding the low/intermediate risk group, dynamic risk stratification was based in the assessment of response to an initial treatment that consisted in total thyroidectomy followed by radioiodine (RAI) treatment. However, lobectomy is now considered a reasonable approach for some low risk patients and the role of postsurgical RAI in the low/intermediate risk group is currently under debate. As a consequence, there are no well-established thyroglobulin (Tg) cut-off points to define categories (e.g. excellent response, biochemical incomplete response) in patients treated with lobectomy or total thyroidectomy without postsurgical RAI treatment. Nonetheless, different thresholds for patients submitted to lobectomy or total thyroidectomy without RAI treatment have been included in clinical recommendations and recently validated in the low risk group. Apart from static Tg levels, the trend of both Tg and Tg-antibodies levels over time, with similar TSH values, has proven to be an effective way of assessing response to treatment. An increase of 20% seems to accurately predict structural disease recurrence. High-risk patients require a very individualized follow-up because most of the patients are expected to have persistent disease after the initial treatment. For these patients, the initial follow-up is mainly aimed at identifying those with progressive disease despite initial treatment. Nonetheless, most impact of dynamic risk stratification in this group occurs when an excellent response is found, precluding patients from an unnecessary aggressive follow-up strategy. In this session, different ways of implementing and refining dynamic risk stratification will be discussed, addressing the low, intermediate and high risk groups.