Time Trends Analysis of Characteristics of Patients with Thyroid Cancer in a Single Medical Center / 대한갑상선학회지

ABSTRACT

BACKGROUND AND OBJECTIVES: The incidence of thyroid cancer is increasing worldwide. The increase in the frequency of screening tests may have led to an over-detection of small thyroid cancers. The Korean Thyroid Association (KTA) discourages the find needle aspiration of thyroid nodules < or =0.5 cm. The aim of this study was to evaluate time trends of characteristics of thyroid cancer patients in a single medical center. MATERIALS AND METHODS: This study included 15,465 patients who underwent operation due to thyroid cancer from 1995 to 2012. Data on age, gender of patients and histology, clinical stage of the thyroid cancer were reviewed retrospectively. RESULTS: New thyroid cancer cases have dramatically increased and papillary thyroid carcinoma (PTC) accounted for a major part of this increase. PTCs were accounted for 98% of all thyroid cancer surgeries in 2012 and 79% in 1995. The proportion of PTCs < or =0.5 cm has increased from 1% in 1995 to 32% in 2009 and then slightly decreased afterward. The peak age of patients with PTC has increased from 40 years in 1995-2000 to 55 years in 2006-2012. The proportion of small follicular thyroid carcinomas and medullary thyroid carcinomas (< or =1.0 cm) also steadily increased during study periods. CONCLUSION: Thyroid cancers became smaller but, increase of very small PTCs stopped after 2010, in which the KTA guidelines were introduced. These findings suggest that the increasing incidence of thyroid cancer in Korea might be due to the over-detection of small thyroid cancers.