Trends in thyroid carcinoma among thyroidectomy patients: a 12-year multicenter study

BACKGROUND: Thyroid malignancy, the most diagnosed cancer of the endocrine system, represents 2% of all malignancies worldwide. The increasing incidence of thyroid cancer has been linked to the increasing sensitivity of modern diagnostic methods which overdiagnosis small thyroid tumors. OBJECTIVES: Assess the distribution and trends in thyroid cancer among thyroidectomy patients. DESIGN: Descriptive, based on medical record review. SETTINGS: Two tertiary care centers in Riyadh. PATIENTS AND METHODS: We included patients who underwent thyroid surgery from January 1, 2004 to December 31, 2016 who ranged in age from 9–90 years regardless of initial diagnosis. MAIN OUTCOME MEASURES: Distribution of thyroid carcinomas by type, age and sex and trends over the time period. SAMPLE SIZE: 979 patients. RESULTS: Of 979 patients, 84.5% were <55 years old, with the majority being female. Thyroid malignancy ranked second to benign tumors, and the most common type of thyroid cancer was papillary thyroid carcinoma (91% of malignant tumors), followed by follicular thyroid cancer (4.7% of malignant tumors). After thyroid microcarcinomas were isolated from the sample and studied separately, we found the overall trend for thyroid cancer to be stable, and that the annual increases in rates were due to increased diagnosis of thyroid microcarcinoma in the period from 2010 to 2016. CONCLUSION: Our study shows that increases in thyroid cancers may be attributed to a rise in the rates of diagnosis of thyroid microcarcinomas. LIMITATIONS: The main limitation is the retrospective nature of this design. Also, a multicenter collaboration would prove beneficial in evaluating the trends of thyroid cancer in Saudi Arabia on a much larger scale. CONFLICT OF INTEREST: None.