Low-Risk Thyroid Cancer: No Benefit of Postsurgical Iodine
After 3 years of follow-up in patients with low-risk differentiated thyroid cancer (DTC), there is no significant difference in the rate of tumor-related events in those treated with postsurgical radioactive iodine (RAI) relative to those who are not, according to a randomized phase 3 trial. The controversy about whether postoperative RAI is beneficial or an overtreatment in low-risk DTC has persisted for years, but it can now be addressed with level one data, according to Sophie Leboulleux, MD, PhD, who heads the thyroid cancer division at Gustave Roussy Cancer Institute, Villejuif, France. The trial, called ESTIMABL2, included 776 low-risk DTC patients managed at 35 participating treatment centers in France. Two to five months after surgery, patients were randomized to receive RAI or to follow-up without RAI if there were no suspicious findings, such as changes in lateral neck lymph nodes, on ultrasonography.
@chandi The prespecified definition was a less than 5% difference in events at the end of 5 years. The 0.8% difference in this study was comfortably within the 95% confidence interval (–3.3%-1.8%). On yearly evaluations under levothyroxine treatment, events were defined as an indication for treatment, whether surgery or RAI administration if there was abnormal RAI intake on the posttherapeutic whole-body scan or elevated thyroglobulin or thyroglobulin antibodies. In the latter case, this was an event even in the absence of abnormal neck ultrasonography.