Endocrine Abstracts

Background: The incidence of differentiated thyroid cancers is increasing, mainly due to the overdiagnosis of small papillary thyroid cancers (less than 1 cm, previously known as microcarcinomas). There is a broad consensus in reducing the surgery extent and the use of radioiodine treatment in low-risk cases by most recent clinical practice guidelines focusing on thyroid cancer treatment. The adoption in real clinical practice is usually slow. The aim of this study is to estimate the changes in real clinical practice, using prospective, observational data of the Italian Thyroid Cancer Observatory (ITCO) study.

Methods: The web-based ITCO database was started in 2013 and now includes prospectively collected data on more than 12 000 patients with confirmed diagnosis of thyroid cancer, from 51 different clinical centers. Data about initial treatment and follow-up clinical assessment are prospectively collected by the treating physicians, according to their usual clinical practice. The study is registered at ClinicalTrials.gov (NCT04031339). For the purposes of this evaluation, we grouped the cases according to the year of the initial treatment: group 1 (2013-2015) and group 2 (2016-2020). We then calculated the rate of patients treated with lobectomy and the rates of patients not submitted to radioiodine ablation, according to their risk of persistent/recurrent disease, as estimated by the system proposed by the 2015 ATA Guidelines for differentiated thyroid cancer.

Results: The final cohorts included 6873 patients. The rates of lobectomies (without completion thyroidectomy) increased from 1.7% to 6.9% (P<0.001) in patients with low risk of persistent or recurrent disease according to the ATA Guidelines, and from 0.6% to 2.3% for intermediate-risk patients (P=0,004). About the radioiodine treatment, its use is decreased from 41.7 to 30.6% in low-risk patients (P<0.001); and from 87.8% to 74.5% in intermediate-risk patients (P<0.001). In all risk classes, the avoidance of radioiodine treatment did not impact the short-term outcomes (as estimated by the 1-year response to treatment, evaluated according to the suggestions of the ATA Guidelines).

Conclusions: For patients with low- or intermediate-risk thyroid cancer, real-world clinical application of practice guidelines is progressively recorded, even if the overall adherence is still low and there is ample room for improvement.