Current controversies in risk-adapted therapy in differentiated thyroid cancer: Is less (therapy) really more?

In recent years, there has been worldwide a significant (relative) increase in "small" thyroid cancer (pT1= tumor size of <= 10mm), which has now reached a plateau. This fact and the absence of prospective and randomized clinical trials are increasingly leading to a discussion of the so-called risk-adapted management of differentiated thyroid cancer. The available studies are partly incomplete, retrospective and difficult to compare. In addition, factors such as different iodine supply, cost-benefit considerations and regional differences in quality of surgical procedures influence the implementation of therapy concepts. Therefore, the therapy of the differentiated thyroid cancer is currently the subject of intensive discussion, especially in "low risk" situations. There is a worldwide trend to classify the risk of differentiated thyroid cancer in general lower than in the past and thus also to reduce the extent of the traditionally recommended therapy. The discussion is increasingly moving from the "one size fits all" towards personalized and thus risk-adapted therapy of the differentiated thyroid cancer. The main goal of this "paradigm shift" is to avoid an "overtreatment" which may be associated with permanent complications due to "unnecessary" surgical procedures and any negative effects of radioiodine ablation. This overview attempts to answer the following questions: When is a risk-adapted therapy for differentiated thyroid cancer justified? What are the consequences in differentiated thyroid cancer if no radioiodine therapy is performed?