Bo Youn Cho

Ablation therapy, such as radioactive iodine (RAI) therapy or thyroidectomy, is generally used as the second-line treatment for Graves’ disease (GD) in Asia. This study investigated changes in the clinical characteristics and outcomes of ablation therapies for GD over 15 years. Patients who underwent ablation therapy between 2001 and 2015 at a single tertiary hospital were included. Among the 10,991 GD patients treated over this 15-year period, 1357 (12.3%) underwent ablation therapy, and the most common reason was intractable GD. The proportion of patients who underwent any type of ablation therapy significantly decreased from 9.0% (2001–2005) to 7.7% (2011–2015). However, the proportion of patients who underwent surgery significantly increased from 1.1% (2001–2005) to 2.4% (2011–2015), and the proportion of patients who received ablation therapy due to suspected thyroid cancer increased from 5% to 13% over time. With a median follow-up duration of 6.2 years, remission was achieved in 86% and 98% of patients in the RAI and surgery groups, respectively, and these rates remained stable over time. In conclusion, although the proportion of patients who underwent ablation therapy for GD decreased during 15 years, the proportion of those who underwent surgery increased in association with the increased rate of suspected thyroid cancers.

Background: Vitamin D deficiency has been known to be associated with the aggressiveness and prognosis of several cancers. In this study, we evaluated the effect of preoperative serum vitamin D level on the aggressiveness and prognosis of papillary thyroid cancer. Methods: In total, 820 patients with papillary thyroid cancer were enrolled. Vitamin D levels were measured in blood samples before surgery. Clinical, pathologic, and recurrence data were accessed to examine the prognostic effects of vitamin D. Patients were categorized into four quartiles by preoperative serum vitamin D levels. Results: Of the enrolled patients, 795 (97%) had insufficient vitamin D levels (< 30 ng/mL). Vitamin D levels showed positive correlations with age and body mass index (BMI) and negative correlations with serum thyroid-stimulating hormone (TSH) levels and anti-thyroid peroxidase antibody titers. The association between vitamin D quartile and the risks of extrathyroidal invasion, lymph node metastasis, advanced cancer stages (III or IV) and risk of recurrence were not significant after adjusting for age, sex, BMI, preoperative ionized calcium and PTH. Additionally, serum vitamin D was not associated with recurrent or persistent papillary thyroid cancer. Conclusion: Serum vitamin D levels are not associated with either disease aggressiveness or poor outcomes among patients with papillary thyroid cancer and vitamin D insufficiency.

Background: Thyroid cancer has increased globally, with a prominent increase in small, papillary thyroid cancers (PTC). The Korean population has a high iodine intake, high prevalence of BRAF V600E mutations, and family histories of thyroid cancer. We examined the clinicopathological characteristics and outcomes of thyroid cancers in Korean patients over four decades. Methods: The medical records of 4500 thyroid cancer patients, between 1962 and 2009 at a single center, including 3147 PTC patients, were reviewed. Results: The mean age of the patients was 46.8±13.2 years; women accounted for 82.9% of the patients, and the median follow-up duration was 4.8 years (mean 7.0±5.8 years, range 1–43 years). The number of patients visiting the clinic increased from 411 during 1962–1990 to 2900 during 2000–2009. Age at diagnosis increased from 39.6±12.9 to 48.6±12.4 years. The male to female ratio increased from 1:6 to 1:4.5. The proportion of small (Conclusions: The incidence of thyroid cancer has rapidly increased, with a decrease in tumors of large size, LN involvement, and ETE, although the decreasing rates of LN involvement and ETE were not as prominent as decreasing rates of large size tumors. The mortality and recurrence rates have also decreased. Future long-term follow-up of patients diagnosed in the most recent decade is needed to confirm the prognostic characteristics of Korean PTC patients.

Background: Familial nonmedullary thyroid carcinoma (FNMTC) is frequently detected, but the prevalence or the aggressiveness of FNMTC is still unclear. We aimed to investigate the prevalence, clinical characteristics, and prognosis of FNMTC. Methods: This study included 3056 nonmedullary thyroid carcinoma (NMTC) patients who were pathologically confirmed to exhibit differentiated thyroid carcinoma from January 1962 through March 2010. The duration of follow-up was 6.2±6.2 years. Results: The prevalence of FNMTC was 9.6%; 37.9% of the FNMTC patients exhibited a parent-offspring relationship, and 62.1% exhibited a sibling relationship. FNMTC was smaller in tumor size (1.2±0.9 vs. 1.4±1.1 cm) and more multifocal (33.6% vs. 27.0%) than sporadic cases. FNMTC presented higher recurrence rates (29.5% vs. 19.8%) and shorter recurrence-free survival than sporadic NMTC (p=0.046). When we compared sporadic NMTC with parent-offspring or sibling FNMTC separately, parent-offspring FNMTC was more multifocal (39.3% vs. 27.0%), while sibling FNMTC was more prevalent in female patients (89.6% vs. 82.5%) and presented smaller tumors (1.2±0.8 vs. 1.4±1.1 cm) than sporadic NMTC. The recurrence rate was higher than that of sporadic NMTC in parent-offspring FNMTC (35.6% vs. 19.8%) but not in sibling FNMTC. Among the 123 parent-offspring FNMTC cases, the second generation exhibited an earlier age at the diagnosis (38±11 vs. 57±11 years), more extrathyroidal invasion (57.8% vs. 29.4%), a higher recurrence rate (50.0% vs. 19.0%), and shorter recurrence-free survival (p=0.015) than the first generation. Conclusion: FNMTC was found to have a very high prevalence in our population. Parent-offspring FNMTC demonstrated higher recurrence than sporadic NMTC; specifically, the second generation of parent-offspring FNMTC cases exhibited more aggressive clinical characteristics than the first generation.

Yi KH, et al. J Korean Soc Radiol. 2011 Apr;64(4):389-416. http://dx.doi.org/10.3348/jksr.2011.64.4.389

Multiple endocrine neoplasia type 2 (MEN2) syndromes are inherited in an autosomal dominant fashion with high penetrance. There are three subtypes, namely, MEN2A (multiple endocrine neoplasia type 2A), MEN2B (multiple endocrine neoplasia type 2B), and familial medullary thyroid carcinoma. The variations in the RET gene play an important role in the MEN2 syndromes. In this work, we have developed a RET oligonucleotide microarray of 67 oligonucleotides to quickly detect RET mutations in MEN2 syndromes. The predominant RET mutations are missense mutations and are restricted to nine codons (codons 609, 611, 618, 620, 630, 634, 768, 804, and 918) in MEN2 syndromes. Missense mutations at codons 609, 611, 618, 620, and 634 have been identified in 98% of MEN2A families and in 85% of familial medullary thyroid carcinoma families. More than 95% of MEN2B patients also had a predominant mutation type at codon 918 (Met-->Thr). RET oligonucleotide microarray can detect RET missense mutations at these nine codons. Theoretically, a total of 55 missense mutation types can occur at eight codons (codons 609, 611, 618, 620, 630, 634, 768, and 804). RET oligonucleotide microarray is designed to detect all of these 55 missense mutation types at these eight codons and one predominant type at codon 918. Fifty-six oligonucleotides were designed for the 56 mutation types at nine codons, and 11 oligonucleotides were designed for the wild types and positive controls. We found RET mutations in all eight of the Korean MEN2A families (a total of 75 members; 27 affected members, 19 gene carriers, and 29 unaffected members) using the developed RET oligonucleotide microarray and an automatic sequencing. Because we found only five mutation types from eight MEN2A families, the international collaborations are required to see whether the RET oligonucleotide microarray may be used as a genetic diagnostic tool. Taken together, the RET oligonucleotide microarray can function as a fast and reliable genetic diagnostic device, which simplifies the process of detecting RET mutations.

The effects of the agents that are related to intracellular events on interferon-gamma-induced class II major histocompatibility complex antigen expression were studied using the technique of immunocytochemistry. Rat class II major histocompatibility complex antigen (RT1.B) was expressed in 88.3 +/- 3.3% (n = 3) of the functioning rat thyroid cells (FRTL-5) cultured in a medium containing 100 U/ml recombinant rat interferon-gamma (IFN gamma). Deprivation of bovine TSH had no effect on the expression of RT1.B antigen by IFN gamma. A23187 (1 nM to 2 microM) and/or 10 nM to 10 microM phorbol 12-myristate 13-acetate did not induce the expression of RT1.B antigen. IFN gamma-induced RT1.B expression was not inhibited by either 10 nM to 100 microM 1-(5-isoquinolysulfonyl)-2-methylpiperazine or 200 nM to 200 microM 8-(N,N-dimethylamino)octyl-3,4,5-trimethoxybenzoate hydrochloride. It was also not inhibited by either 5-200 microM verapamil or 500 nM to 20 microM trifluoperazine. However, 0.01-10 micrograms/ml cycloheximide inhibited IFN gamma-induced RT1.B antigen expression in a dose-dependent manner. These results suggest that IFN gamma induces RT1.B antigen expression in FRTL-5 cells via de novo protein synthesis independent of the cAMP system, phosphatidylinositide system, and voltage-dependent calcium channel.