Trends in the Diagnosis and Treatment of Patients with Medullary Thyroid Carcinoma in Korea

Abstract

Background: Thyroid cancer is becoming increasingly common worldwide, but little is known about the epidemiology of medullary thyroid carcinoma (MTC). This study investigated the current status of the incidence and treatment of MTC using Korean National Health Insurance Service (NHIS) data for the entire Korean population from 2004 to 2016.

Methods: This study included 1,790 MTC patients identified from the NHIS database.

Results: The age-standardized incidence rate showed a slightly decreasing or stationary trend during the period, from 0.25 per 100,000 persons in 2004 to 0.19 in 2016. The average proportion of MTC among all thyroid cancers was 0.5%. For initial surgical treatment, 65.4% of patients underwent total thyroidectomy. After surgery, external-beam radiation therapy (EBRT) was performed in 10% of patients, a proportion that increased from 6.7% in 2004 to 11.0% in 2016. Reoperations were performed in 2.7% of patients (n=49) at a median of 1.9 years of follow-up (interquartile range, 1.2 to 3.4). Since November 2015, 25 (1.4%) patients with MTC were prescribed vandetanib by December 2016.

Conclusion: The incidence of MTC decreased slightly with time, and the proportion of patients who underwent total thyroidectomy was about 65%. EBRT, reoperation, and tyrosine kinase inhibitor therapy are additional treatments after initial surgery for advanced MTC in Korea.

Keywords: Epidemiology; Incidence; Therapeutics; Thyroid cancer, medullary.

Fig. 1

(A) Number of patients with medullary thyroid cancer (MTC) according to age range by year. (B) Number of patients with MTC according to sex by year. (C) Age-standardized incidence rate of MTC by year. (D) Number of MTC patients per 1,000 total thyroid cancers by year.

Fig. 2

(A) Percentage of patients who underwent thyroid surgery (total thyroidectomy and lobectomy) by year. (B) Percentage of patients who underwent external-beam radiation therapy by year. (C) Percentage of patients who underwent radioactive iodine treatment by year.

Fig. 3

(A) Distribution of the interval between the first surgery to the time of reoperation. (B) Number of medullary thyroid cancer (MTC) patients who underwent additional treatments after the first operation. (C) Difference in the rate of reoperation and vandetanib treatment depending on external-beam radiation therapy (EBRT).