Method for improving the speed and pattern quality of a DMD maskless lithography system using a pulse exposure method.

Maskless lithography based on a digital micromirror device (DMD) has the advantages of high process flexibility and a low production cost. However, due to the trade-off relationship between the pixel size and exposure area, it is challenging to achieve high resolutions and high patterning speeds at the same time, which hinders the wider application of this technology in micro- and nano-fabrication processes. In addition, micromirrors in DMDs create pixelated edges that limit the pattern quality. In this paper, we propose a novel DMD maskless lithography method to improve the pattern quality during high-speed continuous patterning by means of pulse exposure and oblique scanning processes. A unique criterion, the pixel occupancy, was devised to determine the parameters related to the pulse exposure and oblique scanning optimally. We also studied how the duty cycle of the pulse exposure affects the pattern quality. As a result, we were able to increase the scanning speed up to the speed limit considering the damage threshold of the DMD and improve the pattern quality by resolving the pixelation problem. We anticipate that this method can be used in various microfabrication fields with short product life cycles or in those that require custom designs, such as the manufacturing of PCBs, MEMS devices, and micro-optics devices, among others.

Difference of stage at cancer diagnosis by socioeconomic status for four target cancers of the National Cancer Screening Program in Korea: Results from the Gwangju and Jeonnam cancer registries.

BACKGROUND: The aim of this study was to evaluate whether stage at cancer diagnosis differed according to patient economic status. METHODS: A total of 10,528 patients with cancer of the stomach, colorectum, breast, or cervix, which are target organs of the Korean National Cancer Screening Program (NCSP; fully implemented in 2005) were extracted from population-based cancer registries. The patients were classified into four groups based on socioeconomic status (SES), as determined using their National Health Insurance (NHI) monthly premium at the time of cancer diagnosis. Cancer stage at diagnosis was defined as early (in situ/local) or late stage (regional/distant) based on the Surveillance, Epidemiology, and End Results (SEER) summary stage. Multivariable logistic regression analysis was performed to estimate the risk of non-local stage using age, residential area, and community deprivation index as covariates. RESULTS: The lowest SES subjects showed significantly higher risks of being diagnosed at a later stage for stomach, colorectal, and female breast cancer, but not for cervical cancer, compared with the highest SES subjects. The estimated ORs were 1.28 (95% CI, 1.10-1.49), 1.29 (95% CI, 1.03-1.61), and 1.35 (95% CI, 1.02-1.81) in the lowest SES subjects with stomach, colorectal, and breast cancer, respectively. CONCLUSIONS: In conclusion, later stage diagnoses of stomach, colon, and female breast cancer are still associated with SES in Korea in the era of the NCSP for the lower SES population.

The association between vitamin D and parathyroid hormone and bone mineral density: the Dong-gu Study.

The primary objective of the present study was to investigate the relationship between 25-hydroxyvitamin D (25[OH]D) and areal bone mineral density (aBMD) in Korean subjects from the general population aged ≥50 years. This study included 8,857 individuals who completed the baseline survey of the Dong-gu study, which was conducted in Korea from 2007-2010. The participants who fulfilled the detailed inclusion criteria underwent assessment of the femoral neck and lumbar spine aBMD as well as measurement of serum 25(OH)D and parathyroid hormone (PTH) levels. After adjusting for other covariates and log-PTH values, the mean aBMD of the femoral neck exhibited a significant increase with increasing 25(OH)D levels in both males (p < 0.001) and females (p = 0.005). Additionally, the mean aBMD of the lumbar spine exhibited a significant increase with increasing 25(OH)D levels in males (p = 0.011) but not females (p = 0.252). After adjusting for covariates and log-25(OH)D values, the mean aBMD values of the femoral neck and lumbar spine showed significant decreases with increasing PTH levels in both males and females (p < 0.001). The present findings demonstrate that the aBMD of the femoral neck was significantly associated with 25(OH)D levels independent of PTH in both males and females and that the aBMD of the lumbar spine was significantly associated with 25(OH)D levels independent of PTH in males, but not females.

Mucocele After Orbital Fracture Repair Masquerading as Optic Neuritis.

The authors report a patient of mucocele formation after orbital wall fracture repair masquerading as optic neuritis.A 38-year-old man with a history of medial orbital wall fracture repair with an alloplastic implant 10 years previously, presented with left visual disturbance and mild ocular pain with movement of the left eye of 3-day duration, and a relative afferent papillary defect in his left eye. He reported having cold symptoms 2 weeks before presentation. His symptoms were typical of retrobulbar optic neuritis. Under suspicion of optic neuritis, computed tomography and magnetic resonance imaging were performed and revealed a large cyst in the sphenoid sinus and ethmoid sinus, just behind the alloplastic implant, that was compressing the medial rectus muscle and optic nerve of the left eye. The patient underwent endoscopic marsupialization of the cyst. Subsequent histologic examinations revealed a cyst lined with ciliated pseudostratified columnar epithelium. The patient had an uncomplicated postoperative course and the visual disturbance resolved. For patients who present solely with optic neuropathy after orbital fracture repair, it is important to be vigilant of potentially rare cause, mucocele formation.

Plasma Folate and Vitamin B12 Levels in Patients with Hepatocellular Carcinoma.

Folate and vitamin B12 involved in the one-carbon metabolism may play a key role in carcinogenesis and progression of hepatocellular carcinoma (HCC) through influencing DNA integrity. The purpose of this study is to evaluate the association of plasma folate and vitamin B12 levels with HCC in a case-control study on 312 HCC patients and 325 cancer-free controls. Plasma concentrations of folate and vitamin B12 in all the subjects were measured by electrochemiluminescence immunoassay. Meanwhile, the information of HCC patients' clinical characteristics including tumor-node-metastasis (TNM) stage, tumor size and tumor markers were collected. The patients of HCC had significantly lower folate levels than those of controls; there was no significant difference in the mean of plasma vitamin B12 levels. We also observed an inverse association between the levels of plasma folate and HCC: the adjusted odds ratios (OR) (95% confidence intervals (CI)) of HCC from the highest to lowest quartile of folate were 0.30 (0.15-0.60), 0.33 (0.17-0.65), and 0.19 (0.09-0.38). Compared to the subjects in the lowest quartile of plasma vitamin B12, only the subjects in the highest quartile of vitamin B12 exhibited a significant positive relationship with HCC, the adjusted OR was 2.01 (95% CI, 1.02-3.98). HCC patients with Stage III and IV or bigger tumor size had lower folate and higher vitamin B12 levels. There was no significant difference in the mean plasma folate levels of the HCC cases in tumor markers status (AFP, CEA and CA19-9 levels), whereas patients with higher CEA or CA19-9 levels retained significantly more plasma vitamin B12 than those with normal-CEA or CA19-9 level. In conclusion, plasma folate and vitamin B12 levels could be associated with HCC, and might be used as predictors of clinical characteristics of HCC patients. However, further prospective studies are essential to confirm the observed results.

Cytocompatible Polymer Grafting from Individual Living Cells by Atom-Transfer Radical Polymerization.

A cytocompatible method of surface-initiated, activator regenerated by electron transfer, atom transfer radical polymerization (SI-ARGET ATRP) is developed for engineering cell surfaces with synthetic polymers. Dopamine-based ATRP initiators are used for both introducing the ATRP initiator onto chemically complex cell surfaces uniformly (by the material-independent coating property of polydopamine) and protecting the cells from radical attack during polymerization (by the radical-scavenging property of polydopamine). Synthetic polymers are grafted onto the surface of individual yeast cells without significant loss of cell viability, and the uniform and dense grafting is confirmed by various characterization methods including agglutination assay and cell-division studies. This work will provide a strategic approach to the generation of living cell-polymer hybrid structures and open the door to their application in multitude of areas, such as sensor technology, catalysis, theranostics, and cell therapy.

APOE Polymorphism Is Associated with C-reactive Protein Levels but Not with White Blood Cell Count: Dong-gu Study and Namwon Study.

We evaluated the association of the APOE polymorphism with serum C-reactive protein levels and white blood cell count in two large population-based studies in Korean. The datasets included the Dong-gu study (n = 8,893) and the Namwon Study (n = 10,032). APOE genotypes were identified by polymerase chain reaction-restriction fragment length polymorphism. Multivariable linear regression analysis was performed to evaluate the relationship of APOE genotypes with C-reactive protein levels and white blood cell count with adjustments for age, sex, body mass index, smoking, diabetes, hypertension, and serum lipids. In the multivariate model, carriers of E3E4 or E4E4 genotype had significantly lower C-reactive protein levels compared with carriers of E3E3 genotype group (0.50 mg/L vs. 0.67 mg/L; 0.37 mg/L vs. 0.67 mg/L, respectively, for the Dong-gu Study and 0.47 mg/L vs. 0.66 mg/L; 0.45 mg/L vs. 0.66 mg/L, respectively, for the Namwon Study). However, there was no difference in white blood cell count among APOE genotypes. We found that the APOE E4 allele is associated with lower C-reactive protein levels, but not white blood cell count. Our results suggest that APOE genotype may influence C-reactive protein levels through non-inflammatory pathway.

Common genetic variants at 1q22 and 10q23 and gastric cancer susceptibility in a Korean population.

Genetic variants at 1q22 and 10q23 were identified as genetic markers of both gastric cancer and esophageal squamous cell carcinoma susceptibility by two genome-wide association studies. The aim of this study was to determine whether rs4072037A > G in MUC1 at 1q22 and rs2274223A > G in PLCE1 at 10q23 are associated with a risk of gastric cancer in a Korean population. We conducted a large-scale case-control study of 3,245 patients with gastric cancer and 1,700 controls. The allele frequencies of rs4072037G and rs2274223G were 11.2 and 25.5% among patients with gastric cancer, compared with 12.8 and 26.4%, respectively, among controls. We found that the rs4072037 AG genotype was significantly associated with a reduced risk of gastric cancer [odds ratios (OR) = 0.78; 95% confidence interval (CI) = 0.67-0.91 for AG vs AA]. Compared with the rs2274223 AA genotype, we found a significant association between the rs2274223 AG genotype and a weakly reduced risk of gastric cancer (OR = 0.87; 95% CI = 0.76-0.99 for AG vs AA). Our data suggest that genetic variants at 1q22 and 10q23 play a role in gastric carcinogenesis.

Dose-response relationship between serum γ-glutamyltransferase and arterial stiffness in Korean adults: the Namwon Study.

BACKGROUND: The results of epidemiologic studies of the association between serum γ-glutamyltransferase (GGT) and brachial-ankle pulse wave velocity (baPWV) have been inconsistent. We examined the association between serum GGT and arterial stiffness in a general population of Korean adults. METHODS: The study population consisted of 6314 community-dwelling Koreans who participated in the baseline survey of the Namwon Study. We analyzed sex-specific association between serum GGT and arterial stiffness, as measured by baPWV. RESULTS: There was a significant progressive increase in age-adjusted mean baPWV across quartiles of GGT in both sexes. In fully adjusted analysis, as compared with the lowest quartile, the odds ratios (95% CI) for high baPWV (ie, sex-specific fifth quintile) were 1.51 (1.03-2.23), 1.82 (1.22-2.72), and 2.80 (1.79-4.40) among men (P-trend <0.001), and 1.11 (0.81-1.52), 1.29 (0.94-1.76), and 1.47 (1.04-2.08) among women (P-trend <0.001), for the second, third, and fourth quartiles of GGT, respectively. CONCLUSIONS: This population-based study examined the dose-response relationship between GGT and arterial stiffness as measured by baPWV in both sexes. The association between GGT and arterial stiffness was stronger among men. Additional longitudinal studies are needed to examine the relationship between GGT and arterial stiffness and clarify the mechanism underlying the association.

Sex-related differences in the association between waist circumference and bone mineral density in a Korean population.

BACKGROUND: Large waist circumference is linked to poor health. Investigations of the relationship between waist circumference, as an index of abdominal fat, and bone mineral density (BMD) have yielded inconsistent results. We investigated the association between abdominal obesity measured using waist circumference and BMD in a large-scale population-based study. METHODS: We enrolled 8981 Korean (3592 males and 5389 females) community-dwelling individuals aged ≥50 years from 2007 to 2010. BMD was measured using dual-energy X-ray absorptiometry at lumbar spine and femoral neck skeletal sites. A multiple linear regression analysis was used to evaluate the relationship between waist circumference quartiles and BMD after adjusting for age, height, weight, and regular exercise. RESULTS: The adjustment for age, height, weight, and regular exercise revealed a negative linear association between quartile of waist circumference and BMD at the femoral neck and lumbar spine sites in males and females. Waist circumference was more strongly correlated with BMD in males than in females. Although the correlations were slightly attenuated following further adjustment for percent body fat, they remained statistically significant. CONCLUSIONS: Our results revealed that waist circumference is independently and inversely associated with BMD after adjusting for age, weight, height, regular exercise and percent body fat, suggesting that waist circumference is a potential predictor of osteoporosis in middle-aged and older Korean males and females.

Gender differences in the association between depressive symptoms and carotid atherosclerosis among middle-aged and older Koreans: the Namwon study.

We investigated the association of depressive symptoms with carotid intima-media thickness (IMT) and plaques in the general Korean population. A total of 7,554 Korean males and females aged 45-74 yr who were free from cardiovascular diseases were included in the analyses. Depressive symptoms were assessed by the Center for Epidemiologic Studies Depression Scale (CES-D). Subjects with a score of ≥16 were classified as having clinically significant depressive symptoms. Carotid ultrasonography was used to measure mean carotid IMT (C-IMT) and to determine the presence of plaques. A significant association between depressive symptoms and C-IMT was observed only in females. After adjustment for established cardiovascular risk factors, females with depressive symptoms had significantly greater C-IMT than females without depressive symptoms (mean difference 0.011±0.004 mm; 95% confidence interval, 0.003-0.019 mm). Compared with controls, the fully adjusted risk of females with depressive symptoms for abnormal C-IMT (≥1.0 mm) was significant (odds ratio, 1.63; 95% confidence interval, 1.16-2.30). No significant association between depressive symptoms and carotid plaques was observed in either gender. This study shows a significant association between depressive symptoms and C-IMT in middle-aged and older females.

High prevalence of vitamin D deficiency in adults aged 50 years and older in Gwangju, Korea: the Dong-gu Study.

Vitamin D plays an important role in bone metabolism and maintaining bone health. Recently, new evidence has revealed that vitamin D affects chronic diseases such as autoimmune diseases, cardiovascular diseases and certain cancers. The aim of this study was to evaluate the vitamin D status and the prevalence of vitamin D deficiency in an urban Korean population. This study included 8,976 participants (3,587 men and 5,389 women) aged 50 yr and older. Serum 25(OH)D level was measured by chemiluminescent microparticle immunoassay. The prevalence of vitamin D deficiency [25(OH)D < 20 ng/mL] was 59.7% and 86.5% in men and women, respectively. The prevalence of vitamin D deficiency increased significantly with age in men, but not in women and it decreased from April to July, more prominently in men than in women. These results suggest that sun exposure, intake of vitamin D supplement, and regular physical activities is recommended in an urban Koreans, especially in women.

Methylenetetrahydrofolate reductase 677 genotype-specific reference values for plasma homocysteine and serum folate concentrations in korean population aged 45 to 74 years: the Namwon study.

The reference interval for plasma total homocysteine (tHcy) and serum folate concentrations were estimated. Total of 3,154 reference individuals (1,029 men and 2,125 women) were selected based on stringent exclusion criteria. For plasma tHcy concentration (µM/L), reference values (median [5-95 percentile]) were 7.72 (5.03 to 13.80) and 6.09 (3.95-10.19) in men and women, respectively. For serum folate concentration (nM/L), reference values were 23.71 (11.73-38.44) and 28.95 (15.23-40.44) in men and women, respectively. The tHcy levels of both genders in the present study were lower than those in previous reports from other countries and Korea.

Polymorphisms in DNA repair genes and MDR1 and the risk for non-Hodgkin lymphoma.

The damage caused by oxidative stress and exposure to cigarette smoke and alcohol necessitate DNA damage repair and transport by multidrug resistance-1 (MDR1). To explore the association between polymorphisms in these genes and non-Hodgkin lymphoma risk, we analyzed 15 polymorphisms of 12 genes in a population-based study in Korea (694 cases and 1700 controls). Four genotypes of DNA repair pathway genes (XRCC1 399 GA, OGG1 326 GG, BRCA1 871 TT, and WRN 787 TT) were associated with a decreased risk for NHL [odds ratio (OR)XRCC1 GA=0.80, p=0.02; OROGG1 GG=0.70, p=0.008; ORBRCA1 TT=0.71, p=0.048; ORWRN TT=0.68, p=0.01]. Conversely, the MGMT 115 CT genotype was associated with an increased risk for NHL (OR=1.25, p=0.04). In the MDR1 gene, the 1236 CC genotype was associated with a decreased risk for NHL (OR=0.74, p=0.04), and the 3435 CT and TT genotypes were associated with an increased risk (OR3435CT=1.50, p<0.0001; OR3435TT=1.43, p=0.02). These results suggest that polymorphisms in the DNA repair genes XRCC1, OGG1, BRCA1, WRN1, and MGMT and in the MDR1 gene may affect the risk for NHL in Korean patients.

Cytoprotective silica coating of individual mammalian cells through bioinspired silicification.

The cytoprotective coating of physicochemically labile mammalian cells with a durable material has potential applications in cell-based sensors, cell therapy, and regenerative medicine, as well as providing a platform for fundamental single-cell studies in cell biology. In this work, HeLa cells in suspension were individually coated with silica in a cytocompatible fashion through bioinspired silicification. The silica coating greatly enhanced the resistance of the HeLa cells to enzymatic attack by trypsin and the toxic compound poly(allylamine hydrochloride), while suppressing cell division in a controlled fashion. This bioinspired cytocompatible strategy for single-cell coating was also applied to NIH 3T3 fibroblasts and Jurkat cells.

Genetic variations in the PRKAA1 and ZBTB20 genes and gastric cancer susceptibility in a Korean population.

A recent genome-wide association study (GWAS) identified new susceptibility single-nucleotide polymorphisms (SNPs) rs13361707 (PRKAA1 and PTGER4 gene on 5p13.1) and rs9841504 (ZBTB20 gene on 3q13.31) that were significantly associated with non-cardia gastric cancer. The aim of this study was to determine whether rs13361707 and rs9841504 polymorphisms are associated with the risk of gastric cancer in a Korean population. We conducted a large-scale case-control study of 3245 gastric cancer patients and 1700 controls. The allele frequencies for rs13361707 C and rs9841504 G were 53.5% and 18.3% among gastric cancer cases, compared with 47.1% and 17.2% among controls, respectively. We found that rs13361707 TC and CC genotypes were associated with increased risk for gastric cancer (odds ratios [OR] = 1.29; 95% confidence interval [CI] = 1.11-1.51 for TC vs. TT and 1.68; 1.41-2.01 for CC vs. TT). However, we found no significant association between rs9841504 and gastric cancer risk (OR = 1.11; 0.97-1.28 for CG vs. CC; OR = 1.09; 0.77-1.53 for GG vs. CC). We observed no significant interactions between rs13361707 and rs9841504 polymorphisms and age, gender, smoking habit, alcohol consumption, and clinicopathologic characteristics such as anatomical tumor location and histological type. Our study showed that the rs13361707 polymorphism was associated with increased risk of gastric cancer in a Korean population. This finding provides further evidence that genetic variant of PRKAA1 and PTGER4 genes may contribute to the gastric carcinogenesis. However, we found no association between rs9841504 and gastric cancer risk.

Racial/ethnic differences in bone mineral density among older women.

The epidemiologic information regarding international differences in bone mineral density (BMD) in women is currently insufficient. We compared BMD in older women across five racial/ethnic groups in four countries. The femoral neck, total hip, and lumbar spine BMD were measured in women (aged 65-74 years) from the Study of Osteoporotic Fractures (SOF) (5,035 Caucasian women and 256 African American women in the US), the Tobago Women's Health Study (116 Afro-Caribbean women), the Ms Os Hong Kong Study (794 Hong Kong Chinese women) and the Namwon Study (1,377 South Korean women). BMD was corrected according to the cross-site calibration results for all scanners. When compared with US Caucasian women, the age adjusted mean BMD measurements at the hip sites were 21-31 % higher among Tobago Afro-Caribbean women and 13-23 % higher among African American women. The total hip and spine BMD values were 4-5 % lower among Hong Kong Chinese women and 4-7 % lower among South Korean women compared to US Caucasians. The femoral neck BMD was similar in Hong Kong Chinese women, but higher among South Korean women compared to US Caucasians. Current/past estrogen use was a significant contributing factor to the difference in BMD between US versus non-US women. Differences in body weight partially explained the difference in BMD between Asian versus non-Asian women. These findings show substantial racial/ethnic differences in BMD even within African or Asian origin individuals, and highlight the contributing role of body weight and estrogen use to the geographic and racial/ethnic variation in BMD.

Sex differences in the associations of testosterone and sex hormone-binding globulin with metabolic syndrome in middle-aged and elderly Koreans: the Namwon study.

BACKGROUND: We investigated the sex-dependent associations of testosterone and sex hormone-binding globulin (SHBG) levels with metabolic syndrome (MetS). METHODS AND RESULTS: We conducted a cross-sectional study of 9,424 community-dwelling adults aged 45-74 years (median age, 63.7 years). MetS was defined according to the updated version of the National Cholesterol Education Program Adult Treatment Panel III criteria. Serum total testosterone (TT) and SHBG levels were determined using a chemiluminescent microparticle immunoassay, and free testosterone (FT) concentrations were calculated. In a multivariate analysis, TT levels were inversely associated with MetS in men (odds ratio [OR] of each standard deviation increase in the logarithmic value, 0.70; 95% confidence interval [CI], 0.65-0.76), whereas they were positively associated in women (OR, 1.17; 95% CI, 1.10-1.24). FT levels were positively associated with MetS in women only (OR, 1.39; 95% CI, 1.30-1.49). However, SHBG levels were negatively associated with MetS in both men (OR, 0.57; 95% CI, 0.52-0.61) and women (OR, 0.61; 95% CI, 0.57-0.66). CONCLUSIONS: Our data showed that higher TT levels were associated with a reduced prevalence of MetS in men and an elevated prevalence of MetS in women. Higher SHBG levels were associated with decreased prevalence of MetS in both sexes. These results suggest sex differences in the associations of endogenous testosterone and SHBG with MetS.

Sex-specific differences in the association between ABO genotype and gastric cancer risk in a Korean population.

BACKGROUND: Although previous studies have demonstrated an association between ABO blood group and the risk of gastric cancer (GC), only one study has identified these associations using the ABO genotype; however, that study did not evaluate sex differences in this association. The aim of the present study was to investigate whether there are sex-specific differences in the ABO genotype-associated risk of GC. In addition, we explored the association of the ABO genotype and the clinicopathologic characteristics of GC in a Korean population. METHODS: We conducted a large-scale case-control study of 3245 GC patients (2204 males, 1041 females) and 1700 controls (821 males, 879 females). The ABO genotype was determined by multicolor real-time polymerase chain reaction (PCR) using displacing probes. RESULTS: As compared with genotype OO, genotypes AA and AO in females, but not in males, were associated with a significantly increased risk of GC (odds ratio [OR] 1.56 and 95 % confidence interval [CI] 1.08-2.26 for AA; OR 1.57 and 95 % CI 1.21-2.03 for AO). In a subgroup analysis, blood group A had a significantly increased risk of diffuse-type GC (OR 2.00, 95 % CI 1.43-2.78), but not of intestinal-type (OR 1.31, 95 % CI 0.96-1.79) or mixed-type GC (OR 1.43, 95 % CI 0.92-2.24). CONCLUSION: The ABO genotypes AA and AO were significantly associated with GC only in females and only for diffuse-type GC. These data suggest that the association between ABO blood group and GC risk may differ according to sex and histological type.

Thyroid cancer is the most common cancer in women, based on the data from population-based cancer registries, South Korea.

Similar to worldwide trends, the incidence of thyroid cancer in South Korea has increased steadily in recent decades. We examined the trends in thyroid cancer incidence in Gwangju and Jeonnam provinces between 1996 and 2010, and identified 19 881 cases (men 3282/16.5%; women 16 599/83.5%) from the Gwangju Cancer Registry and Jeonnam Cancer Registry databases, which are population-based cancer registries. Age-standardized incidence rates per 100 000 persons, using hypothetical world standard population (Segi), increased from 1.9 in 1996 to 27.0 in 2010 in men, and from 10.6 to 111.3 in women, respectively. The estimated annual percentage changes (95% confidence interval) of age-standardized incidence rates were 27.1% (24.6-29.6) and 19.7% (16.4-23.2) for men and women, respectively, during the same period. The proportion of papillary-type thyroid cancer increased from 74.2 and 75.4% in 1996 to 97.9 and 98.3% in 2010 for men and women, respectively. We found the most prominent increasing trends and the highest incidence rate of thyroid cancer among those that have ever been reported. Thyroid cancer has been the leading cancer in women since 2003 and is now the fifth most common cancer in men in Gwangju and Jeonnam, South Korea.