The Efficacy and Safety of an Indocyanine Green-Macroaggregated Albumin-Hyaluronic Acid Mixture (LuminoMark™) for Surgical Localization of Recurrent Thyroid Cancer

BACKGROUND

The recurrence of thyroid cancer poses challenges compounded by postoperative fibrosis and anatomic changes. By overcoming the limitations of current localizing dye techniques, indocyanine green-macroaggregated albumin-hyaluronic acid (ICG-MAA-HA) mixture dye promises improved localization. This study aimed to evaluate the efficacy and safety of the dye for recurrent thyroid cancer.

METHODS

The nine patients in this study underwent surgery and postoperative ultrasonography. The dye was injected into recurrent lesions in all the patients preoperatively. During surgery, the lesions were confirmed with an imaging system before and after excision. If the lesion was unidentifiable with the naked eye, surgical excision was performed under the corresponding fluorescent guide. Side effects related to the dye injection and completeness of the surgery were evaluated.

RESULTS

No side effects such as bleeding, skin tattooing, or pain during or after the dye injection were reported, and no discoloration occurred that interfered with the surgical field of view during surgery. In three cases (33.3 %), because it was difficult to localize metastatic lesions with the naked eye, the operation was successfully completed using an imaging system. The completeness of the surgical resection was confirmed by ultrasonography after an average of 5 months postoperatively.

CONCLUSION

The study found that ICG-MAA-HA dye effectively located metastatic and recurrent thyroid cancer and had favorable results in terms of minimal procedural side effects and potential for assisting the surgeon. A large-scale multi-institutional study is necessary to prove the clinical significance regarding patient survival and disease control.

Data-Efficient Computational Pathology Platform for Faster and Cheaper Breast Cancer Subtype Identifications: Development of a Deep Learning Model

BACKGROUND

Breast cancer subtyping is a crucial step in determining therapeutic options, but the molecular examination based on immunohistochemical staining is expensive and time-consuming. Deep learning opens up the possibility to predict the subtypes based on the morphological information from hematoxylin and eosin staining, a much cheaper and faster alternative. However, training the predictive model conventionally requires a large number of histology images, which is challenging to collect by a single institute.

OBJECTIVE

We aimed to develop a data-efficient computational pathology platform, 3DHistoNet, which is capable of learning from z-stacked histology images to accurately predict breast cancer subtypes with a small sample size.

METHODS

We retrospectively examined 401 cases of patients with primary breast carcinoma diagnosed between 2018 and 2020 at the Department of Pathology, National Cancer Center, South Korea. Pathology slides of the patients with breast carcinoma were prepared according to the standard protocols. Age, gender, histologic grade, hormone receptor (estrogen receptor [ER], progesterone receptor [PR], and androgen receptor [AR]) status, erb-B2 receptor tyrosine kinase 2 (HER2) status, and Ki-67 index were evaluated by reviewing medical charts and pathological records.

RESULTS

The area under the receiver operating characteristic curve and decision curve were analyzed to evaluate the performance of our 3DHistoNet platform for predicting the ER, PR, AR, HER2, and Ki67 subtype biomarkers with 5-fold cross-validation. We demonstrated that 3DHistoNet can predict all clinically important biomarkers (ER, PR, AR, HER2, and Ki67) with performance exceeding the conventional multiple instance learning models by a considerable margin (area under the receiver operating characteristic curve: 0.75-0.91 vs 0.67-0.8). We further showed that our z-stack histology scanning method can make up for insufficient training data sets without any additional cost incurred. Finally, 3DHistoNet offered an additional capability to generate attention maps that reveal correlations between Ki67 and histomorphological features, which renders the hematoxylin and eosin image in higher fidelity to the pathologist.

CONCLUSIONS

Our stand-alone, data-efficient pathology platform that can both generate z-stacked images and predict key biomarkers is an appealing tool for breast cancer diagnosis. Its development would encourage morphology-based diagnosis, which is faster, cheaper, and less error-prone compared to the protein quantification method based on immunohistochemical staining.

Development and Verification of Time-Series Deep Learning for Drug-Induced Liver Injury Detection in Patients Taking Angiotensin II Receptor Blockers: A Multicenter Distributed Research Network Approach

OBJECTIVES

The objective of this study was to develop and validate a multicenter-based, multi-model, time-series deep learning model for predicting drug-induced liver injury (DILI) in patients taking angiotensin receptor blockers (ARBs). The study leveraged a national-level multicenter approach, utilizing electronic health records (EHRs) from six hospitals in Korea.

METHODS

A retrospective cohort analysis was conducted using EHRs from six hospitals in Korea, comprising a total of 10,852 patients whose data were converted to the Common Data Model. The study assessed the incidence rate of DILI among patients taking ARBs and compared it to a control group. Temporal patterns of important variables were analyzed using an interpretable timeseries model.

RESULTS

The overall incidence rate of DILI among patients taking ARBs was found to be 1.09%. The incidence rates varied for each specific ARB drug and institution, with valsartan having the highest rate (1.24%) and olmesartan having the lowest rate (0.83%). The DILI prediction models showed varying performance, measured by the average area under the receiver operating characteristic curve, with telmisartan (0.93), losartan (0.92), and irbesartan (0.90) exhibiting higher classification performance. The aggregated attention scores from the models highlighted the importance of variables such as hematocrit, albumin, prothrombin time, and lymphocytes in predicting DILI.

CONCLUSIONS

Implementing a multicenter-based timeseries classification model provided evidence that could be valuable to clinicians regarding temporal patterns associated with DILI in ARB users. This information supports informed decisions regarding appropriate drug use and treatment strategies.

Progression of Low-Risk Papillary Thyroid Microcarcinoma During Active Surveillance: Interim Analysis of a Multicenter Prospective Cohort Study of Active Surveillance on Papillary Thyroid Microcarcinoma in Korea

Background: Active surveillance (AS) is an alternative to thyroidectomy for the management of low-risk papillary thyroid microcarcinoma (PTMC). However, prospective AS data collected from diverse populations are needed. Methods: This multicenter prospective cohort study enrolled patients from three referral hospitals in Korea. The participants were self-assigned into two groups, AS or immediate surgery. All patients underwent neck ultrasound every 6-12 months to monitor for disease progression. Progression under AS was evaluated by a criterion of tumor size increment by 3 mm in one dimension (3 mm), 2 mm in two dimensions (2 × 2 mm), new extrathyroidal extension (ETE), or new lymph node metastasis (LNM), and a composite outcome was defined using all four criteria. Results: A total of 1177 eligible patients with PTMC (919 female, 78.1%) with a median age of 48 years (range 19-87) were enrolled; 755 (64.1%) patients chose AS and 422 (35.9%) underwent surgery. Among 755 patients under AS, 706 (female 537, 76.1%) underwent at least two ultrasound examinations and were analyzed. Over a follow-up period of 41.4 months (standard deviation, 16.0), 163 AS patients (23.1%) underwent surgery. Progression defined by the composite outcome was observed in 9.6% (68/706) of patients, and the 2- and 5-year progression estimates were 5.3% and 14.2%, respectively. The observed progression rates were 5.8% (41/706) and 5.4% (38/706) as defined by tumor size enlargement by 3 mm and 2 × 2 mm, respectively, and 1.3% (9/706) and 0.4% (3/706) for new LNM and ETE, respectively. No distant metastases developed during AS. In multivariate logistic regression analysis examining variables associated with progression under AS, age at diagnosis <30 years (odds ratio [OR], 2.86; 95% confidence interval [CI], 1.10 - 7.45), male sex (OR, 2.48; 95% CI, 1.47 - 4.20), and tumor size ≥6 mm (OR, 1.89; 95% CI, 1.09 - 3.27) were independently significant. Conclusions: The progression of low-risk PTMC during AS in the Korean population was low, but slightly higher than previously reported in other populations. Risk factors for disease progression under AS include younger age, male sex, and larger tumor size. Clinical trial registration: Clinicaltrials.gov NCT02938702.

Long-term clinical outcomes of oral antidiabetic drugs as fixed-dose combinations: A nationwide retrospective cohort study

AIM

To compare treatment patterns and clinical outcomes of single-pill fixed-dose combination (FDC) and two-pill combination (TPC) therapies using real-world data.

METHODS

We conducted a nationwide retrospective cohort study using South Korea's healthcare database (2002-2015). We identified two cohorts of incident patients with type 2 diabetes who initiated FDC or TPC therapy within 4 months of their first prescription for metformin or sulphonylurea. We examined persistence and adherence patterns and the clinical outcome of a composite endpoint of death or hospitalization for acute myocardial infarction, heart failure or stroke and compared the differences in treatment patterns and clinical outcomes using Cox models.

RESULTS

Of 5143 and 10 973 patients who initiated FDC and TPC therapy, respectively, we identified 5143 patient pairs after propensity score matching. The FDC group exhibited greater median time to treatment discontinuation (163 vs. 146 days), and proportion of days covered at 12 months (mean 0.60 vs. 0.57, P < .0001) and at 24 months (0.53 vs. 0.51, P = .014) than the TPC group. The FDC group, compared with the TPC group, had reduced risks of the composite clinical outcome (hazard ratio 0.86, 95% confidence intervals 0.77-0.97) and hospitalization for stroke (0.80, 0.67-0.96).

CONCLUSION

FDC therapy may provide favourable cardiovascular benefits, especially reducing the risk of hospitalization for stroke, and has better medication adherence among patients with type 2 diabetes.

A Cross-Sectional Survey of Patient Treatment Choice in a Multicenter Prospective Cohort Study on Active Surveillance of Papillary Thyroid Microcarcinoma (MAeSTro)

Background: Active surveillance (AS) is offered as a choice to patients with low-risk papillary thyroid microcarcinoma (PTMC). This study aimed to identify patient and physician factors associated with the choice of AS. Methods: We conducted a cross-sectional survey of patients with low-risk PTMC who were enrolled in a prospective study comparing outcomes following AS and surgery. Patients completed a questionnaire to assess their prior knowledge of the disease, considerations in the decision-making process, and reasons for choosing the treatment. We also surveyed 19 physician investigators about their disease management preferences. Variables affecting the patients' choice of AS, including patients' characteristics and their decision-making process, were analyzed in a multivariable analysis. Results: The response rate of the patient survey was 72.8% (857/1177). Among the patients who responded to the survey, 554 patients (128 male; mean age 49.4 ± 11.6 years; response rate 73.4%) with low-risk PTMC chose AS (AS group), whereas 303 patients (55 male; 46.6 ± 10.7 years; 71.8%) chose immediate surgery (iOP group). In the AS group, 424 patients (76.5%) used a decision aid, and 144 (47.5%) used it in the iOP group. The choice of AS was associated with the following variables: patient age >50 years (odds ratio 1.713 [confidence interval, CI 1.090-2.690], p = 0.020), primary tumor size ≤5 mm (odds ratio 1.960 [CI 1.137-3.379], p = 0.015), and consulting an endocrinologist (odds ratio 114.960 [CI 48.756-271.057], p < 0.001), and use of a decision aid (odds ratio 2.469 [CI 1.320-4.616], p = 0.005). The proportion of patients who were aware of AS before their initial consultation for treatment decision was higher in the AS group than in the iOP group (64.6% vs. 56.8%). Family members were reported to have influenced the treatment decisions more in the iOP group (p = 0.025), whereas the AS group was more influenced by information from the media (p = 0.017). Physicians' attitudes regarding AS of low-risk PTMC tended to be more favorable among endocrinologists than surgeons and all became more favorable as the study progressed. Conclusions: Emerging evidence suggests that physicians' attitudes and communication tools influence the treatment decision of low-risk PTMC patients. Support is needed for patient-centered decision making. (Clinical trial No: NCT02938702).

Seaweed and Iodine Intakes and SLC5A5 rs77277498 in Relation to Thyroid Cancer

BACKGRUOUND

This study aims to elucidate the associations among dietary seaweed (gim and miyeok/dashima) and iodine intakes, the rs77277498 polymorphism of the SLC5A5 gene codifying the sodium/iodine symporter, and thyroid cancer risk in a Korean population.

METHODS

We conducted a case-control study of 117 thyroid cancer cases and 173 controls who participated in the Cancer Screenee Cohort between 2002 and 2014 at the National Cancer Center, Korea. The amount of seaweed and iodine consumption (g/day) was estimated using the residual energy adjustment method. We calculated odds ratios (ORs) and their 95% confidence intervals (CIs) using a multivariable logistic regression model for the separate and combined effect of dietary iodine-based intake and SLC5A5 polymorphism (rs77277498, C>G) on thyroid cancer.

RESULTS

Dietary gim and iodine intakes were inversely associated with thyroid cancer, with ORs of 0.50 (95% CI, 0.30 to 0.83) and 0.57 (95% CI, 0.35 to 0.95), respectively, whereas the associations for dietary miyeok/dashima and total seaweed intakes were not significant. However, compared with individuals carrying the C/C genotype of the rs77277498 polymorphism with a low intake of all dietary factors, those carrying the G allele with a high intake had a lower risk of thyroid cancer, with ORs of 0.25 (95% CI, 0.10 to 0.56), 0.31 (95% CI, 0.12 to 0.77), 0.26 (95% CI, 0.10 to 0.62), and 0.30 (95% CI, 0.12 to 0.73) for the consumption of gim, miyeok/dashima, total seaweed, and iodine, respectively.

CONCLUSION

In summary, our results supported the evidence of the protective effects of dietary gim and iodine intake against thyroid cancer risk, and this association can be strengthened by SLC5A5 rs77277498 genotypes.

Application of Machine Learning to Identify Clinically Meaningful Risk Group for Osteoporosis in Individuals Under the Recommended Age for Dual-Energy X-Ray Absorptiometry

Dual-energy X-ray absorptiometry (DXA) is the gold standard for diagnosing osteoporosis; it is generally recommended in men ≥ 70 and women ≥ 65 years old. Therefore, assessment of clinical risk factors for osteoporosis is very important in individuals under the recommended age for DXA. Here, we examine the diagnostic performance of machine learning-based prediction models for osteoporosis in individuals under the recommended age for DXA examination. Data of 2210 men aged 50-69 and 1099 women aged 50-64 obtained from the Korea National Health and Nutrition Examination Survey IV-V were analyzed. Extreme gradient boosting (XGBoost) was used to find relevant clinical features and applied to three machine learning models: XGBoost, logistic regression, and a multilayer perceptron. For the prediction of osteoporosis, the XGBoost model using the top 20 features extracted from XGBoost showed the most reliable performance with area under the receiver operating characteristic curve (AUROC) of 0.73 and 0.79 in men and women, respectively. We compared the diagnostic accuracy of the Shapley additive explanation values based on a risk-score model obtained from XGBoost and conventional osteoporosis risk assessment tools for prediction of osteoporosis using optimal cut-off values for each model. We observed that a cut-off risk score of ≥ 28 in men and ≥ 47 in women was optimal to classify a positive screening for osteoporosis (an AUROC of 0.86 in men and 0.91 in women). The XGBoost-based osteoporosis-prediction model outperformed conventional risk assessment tools. Therefore, machine learning-based prediction models are a more suitable option than conventional risk assessment methods for screening osteoporosis in individuals under the recommended age for DXA examination.

Metabolic Effects of Gastrectomy and Duodenal Bypass in Early Gastric Cancer Patients with T2DM: A Prospective Single-Center Cohort Study

We evaluated the metabolic effects of gastrectomies and endoscopic submucosal dissections (ESDs) in early gastric cancer (EGC) patients with type 2 diabetes mellitus (T2DM). Forty-one EGC patients with T2DM undergoing gastrectomy or ESD were prospectively evaluated. Metabolic parameters in the patients who underwent gastrectomy with and without a duodenal bypass (groups 1 and 2, n = 24 and n = 5, respectively) were compared with those in patients who underwent ESD (control, n = 12). After 1 year, the proportions of improved/equivocal/worsened glycemic control were 62.5%/29.2%/8.3% in group 1, 40.0%/60.0%/0.0% in group 2, and 16.7%/50.0%/33.3% in the controls, respectively (p = 0.046). The multivariable ordered logistic regression analysis results showed that both groups had better 1-year glycemic control. Groups 1 and 2 showed a significant reduction in postprandial glucose (−97.9 and −67.8 mg/dL), body mass index (−2.1 and −2.3 kg/m²), and glycosylated hemoglobin (group 1 only, −0.5% point) (all p < 0.05). Furthermore, improvements in group 1 were more prominent when preoperative leptin levels were high (p for interaction < 0.05). Metabolic improvements in both groups were also observed for insulin resistance, leptin, plasminogen activator inhibitor-1, and resistin. Gastrectomy improved glycemic control and various metabolic parameters in EGC patients with T2DM. Patients with high leptin levels may experience greater metabolic benefits from gastrectomy with duodenal bypass.

Global Trends of Regional Health Information Systems and Suggested Strategic Utilization of their Medical Information

Objectives

Along with the exponentially-growing data produced and accumulated every day through mobile platforms, social networking services, the Internet, and other media, information is becoming increasingly important as a strategic resource. This report presents specific and clear directions and suggests empirical project plans regarding innovations in regional health information systems to promote the utilization of medical information.

Methods

We reviewed and examined documents about global trends and examples of regional health information systems. The problems and solutions of health information utilization and regional health information systems in Korea were analyzed.

Results

This study presented examples of the establishment of health information systems, problems in the use of local healthcare information, and an empirical project for improvement.

Conclusions

The results of this study imply the need for long-term and systematic approaches for the use of medical information and the establishment of a local healthcare information system, along with implementation plans. As a first step, it is imperative to clarify the goal of building a medical information system, the information that must be provided to build the system, and the data that should be collected to provide such information, while moving away from the mentality of focusing on technology-oriented medical information services. In addition, it is necessary to consider information governance, data-based service development, and the medical innovation framework, which are ways to efficiently manage, utilize, and systemize the data to be collected.

Can computed tomography scanning in adults lead to an increased risk of thyroid cancer? A nationwide nested case-control study

OBJECTIVE

To evaluate the association between computed tomography (CT) scanning and newly diagnosed thyroid cancer cases in relation to the confounding effect of the healthcare utilization rate.

METHODS

This nested case-control study used the Korean National Health Insurance Service-National Sample Cohort 2002-2015: 3557 adult thyroid cancer cases were matched to 17,785 controls by age, sex, and diagnosis date. Odds ratios (ORs) were estimated for thyroid cancer associated with cumulative exposure to CT scanning > 3 years before cancer diagnosis. Changes in estimated ORs with and without adjustment for outpatient visit frequency were investigated.

RESULTS

ORs for newly diagnosed thyroid cancer increased according to the higher number of total CT scans and thyroid-exposing CT scans (CT scans of the head, neck, or chest compartment; OR and 95% confidence interval [CI], 1.09 [1.03-1.16] and 1.28 [1.05-1.57], respectively). ORs for thyroid cancer increased according to higher outpatient visit frequency. The association between thyroid cancer incidence and CT scans became insignificant when outpatient visit frequency was adjusted in the models (OR [95% CI], 1.03 [0.97-1.10]: total CT scans, 1.14 [0.93-1.41]: thyroid-exposing CT scans). Subgroup analyses stratified by age, sex, and history of other malignancies did not reveal independent associations between CT scanning and thyroid cancer.

CONCLUSIONS

The high incidence of thyroid cancer in adults exposed to ionizing radiation during CT scanning can be largely explained by the confounding effect of the healthcare utilization rate. These effects should be considered to avoid overestimation of the CT scanning-associated risk of thyroid cancer.

KEY POINTS

• Studies indicate that diagnostic imaging using low-ionizing radiation may increase risks for thyroid cancer in adults. • Our findings suggest that the risk for radiation-induced thyroid cancer following CT scanning in adults may have been overestimated in observational studies due to medical surveillance-related biases.

Evaluation of modifiable factors and polygenic risk score in thyroid cancer

The cumulative effect of single-nucleotide polymorphisms (SNPs) on thyroid cancer has been adequately defined in individuals of European ancestry; however, similar evidence in the Korean population is limited. This study aimed to investigate the influence of modifiable factors and the polygenic risk score (PRS) and their interactive and combined effects on thyroid cancer. Using data from the cancer screenee cohort, this study included 759 thyroid cancer cases and 759 age- and sex-matched controls. We examined the effects of tobacco smoking, alcohol consumption, and regular exercise habits, BMI, and the PRS of six SNPs on thyroid cancer. Odds ratios (ORs) and 95% confidence intervals (CIs) for the associations were obtained using a conditional logistic regression model. The results indicated that family history, obesity, and the unweighted and weighted PRS were independently associated with susceptibility to thyroid cancer, with ORs (95% CIs) of 2.96 (1.63-5.36), 1.72 (1.20-2.48), 1.46 (1.10-1.93), and 1.56 (1.19-2.03), respectively, whereas the effect of smoking, drinking, and regular exercise was not significant. The contribution of the PRS remained after stratifying participants with healthy behaviors, such as nonsmokers/nondrinkers, and regular exercise. Although the PRS did not significantly contribute to the risk for thyroid cancer when participants were stratified according to BMI, BMI and the PRS had a cumulative effect on thyroid cancer risk. The combined effect of genetic polymorphisms on predisposition to thyroid cancer may differ based on tobacco smoking, alcohol consumption, regular exercise behaviors and cumulative BMI. Larger population-based studies are needed to validate these findings.

Effect of Helicobacter pylori treatment on the long-term mortality in patients with type 2 diabetes

BACKGROUND/AIMS

Meta-analyses of randomized trials reported a non-significant increase in overall mortality risk after Helicobacter pylori eradication. In this study, we investigated whether H. pylori treatment is associated with increased risk of overall mortality in patients with type 2 diabetes.

METHODS

In this retrospective population-based cohort study, we identified 66,706 patients treated for type 2 diabetes between 2002 and 2010 from the Korean National Health Insurance Service-National Sample Cohort. Patients who received H. pylori treatment (Hp-treatment cohort, 1,727 patients) were matched to those who did not (non-treatment cohort, 3,454 patients) at a 1:2 ratio. The primary outcome was overall mortality. The secondary outcomes were mortalities due to cardiovascular disease, cerebrovascular disease, or cancers. To estimate hazard ratio (HR) with confidential interval (CI), we used the Cox proportional-hazard model.

RESULTS

During a median follow-up of 4.7 years, the overall mortality was 5.9% (101/1,727 patients) among patients in the Hp-treatment cohort and 7.6% (364/3,454 patients) among patients in the non-treatment cohort. Adjusted HR (aHR) for overall mortality in the Hp-treatment cohort was 0.74 (95% CI, 0.59 to 0.93; p = 0.011). The mortality risks due to cardiovascular disease (aHR, 1.34; 95% CI, 0.54 to 3.30; p = 0.529), cerebrovascular disease (aHR, 0.97; 95% CI, 0.37 to 2.55; p = 0.947), and cancer (aHR, 1.08; 95% CI, 0.68 to 1.72; p = 0.742) were not significantly different between the groups.

CONCLUSION

In type 2 diabetes patients, overall mortality did not increase after H. pylori treatment.

Impact of image compression on deep learning-based mammogram classification

Image compression is used in several clinical organizations to help address the overhead associated with medical imaging. These methods reduce file size by using a compact representation of the original image. This study aimed to analyze the impact of image compression on the performance of deep learning-based models in classifying mammograms as "malignant"-cases that lead to a cancer diagnosis and treatment-or "normal" and "benign," non-malignant cases that do not require immediate medical intervention. In this retrospective study, 9111 unique mammograms-5672 normal, 1686 benign, and 1754 malignant cases were collected from the National Cancer Center in the Republic of Korea. Image compression was applied to mammograms with compression ratios (CRs) ranging from 15 to 11 K. Convolutional neural networks (CNNs) with three convolutional layers and three fully-connected layers were trained using these images to classify a mammogram as malignant or not malignant across a range of CRs using five-fold cross-validation. Models trained on images with maximum CRs of 5 K had an average area under the receiver operating characteristic curve (AUROC) of 0.87 and area under the precision-recall curve (AUPRC) of 0.75 across the five folds and compression ratios. For images compressed with CRs of 10 K and 11 K, model performance decreased (average 0.79 in AUROC and 0.49 in AUPRC). Upon generating saliency maps that visualize the areas each model views as significant for prediction, models trained on less compressed (CR <  = 5 K) images had maps encapsulating a radiologist's label, while models trained on images with higher amounts of compression had maps that missed the ground truth completely. In addition, base ResNet18 models pre-trained on ImageNet and trained using compressed mammograms did not show performance improvements over our CNN model, with AUROC and AUPRC values ranging from 0.77 to 0.87 and 0.52 to 0.71 respectively when trained and tested on images with maximum CRs of 5 K. This paper finds that while training models on images with increased the robustness of the models when tested on compressed data, moderate image compression did not substantially impact the classification performance of DL-based models.

Incidence and disease course of new-onset diabetes mellitus in breast and colorectal cancer patients undergoing chemotherapy: A prospective multicenter cohort study

AIMS

To investigate the incidence of and risk factors for new-onset type 2 diabetes mellitus (DM) developed during chemotherapy that included steroids in cancer patients without DM.

METHODS

This multicenter, prospective, and observational cohort study enrolled 299 cancer patients without DM (aged > 18 years), planning 4-8 cycles of adjuvant chemotherapy. The endpoints were the incidence, remission rate, and independent determinants of new-onset DM during chemotherapy.

RESULTS

Between April 2015 and March 2018, 270 subjects with colorectal cancer or breast cancer (mean age, 51.0 years) completed the follow up (mean 39 months). Of whom, 17 subjects (6.3%) developed DM within a median time of 90 days (range, 17-359 days). Male sex (hazard ratio [HR], 15.839; 95% confidence interval [CI], 2.004-125.20) and impaired fasting glucose (IFG) at baseline (HR, 8.307; CI, 1.826-37.786) were independent risk factors. Six months after chemotherapy completion, 11/17 subjects (64.7%) experienced DM remission, associated with a significantly higher C-peptide level at baseline (C-peptide levels, 1.3 ng/mL in subjects with remission and 0.9 ng/mL in subjects without remission, age- and sex-adjusted P = 0.007).

CONCLUSIONS

DM incidence was 6.3% in patients who received chemotherapy with dexamethasone. Close monitoring for hyperglycemia is recommended, especially for men with IFG.

TRIAL REGISTRATION

ClinicalTrials.gov (NCT03062072).

Effect of Initial Treatment Choice on 2-year Quality of Life in Patients with Low-risk Papillary Thyroid Microcarcinoma

CONTEXT

The long-term quality of life (QoL) in patients with low-risk papillary thyroid microcarcinoma (PTMC) underwent active surveillance (AS) and immediate surgery is unclear.

OBJECTIVE

The aim of this study was to investigate the effect of initial treatment choice on 2-year QoL in patients with low-risk PTMC.

DESIGN, SETTING, AND PARTICIPANTS

We analyzed 2652 QoL surveys from 1055 subjects enrolled in ongoing multicenter prospective cohort study on active surveillance of PTMC, in which the median follow-up duration was 24.4 months.

MAJOR OUTCOME MEASURE

We evaluated QoL of patients with low-risk PTMC according to their treatment modality using generalized estimating equation.

RESULTS

Six hundred and seventy-four subjects (male = 161; mean age = 48.8 ± 11.9 years) with low-risk PTMC chose AS while 381 subjects (male = 75; mean age = 45.7 ± 10.4 years) chose immediate surgery, including lobectomy/isthmusectomy (L/I) and total thyroidectomy (TT). Among the 817 subjects who completed baseline QoL surveys, 2-year QoL was good in order of AS (n = 500), L/I (n = 238), and TT (n = 79) groups after adjustment for age, sex, baseline tumor size, and baseline QoL scores. Among the 101 subjects who changed their treatment from AS to surgery during the follow-up period, 35 subjects who changed treatment due to disease progression had better QoL than 66 subjects who had no disease progression.

CONCLUSIONS

This study identified QoL as a major issue in choosing an initial treatment of low-risk PTMC and highlighted the possibility of using AS as the primary treatment.

Prediction of Prolonged Length of Hospital Stay After Cancer Surgery Using Machine Learning on Electronic Health Records: Retrospective Cross-sectional Study

BACKGROUND

Postoperative length of stay is a key indicator in the management of medical resources and an indirect predictor of the incidence of surgical complications and the degree of recovery of the patient after cancer surgery. Recently, machine learning has been used to predict complex medical outcomes, such as prolonged length of hospital stay, using extensive medical information.

OBJECTIVE

The objective of this study was to develop a prediction model for prolonged length of stay after cancer surgery using a machine learning approach.

METHODS

In our retrospective study, electronic health records (EHRs) from 42,751 patients who underwent primary surgery for 17 types of cancer between January 1, 2000, and December 31, 2017, were sourced from a single cancer center. The EHRs included numerous variables such as surgical factors, cancer factors, underlying diseases, functional laboratory assessments, general assessments, medications, and social factors. To predict prolonged length of stay after cancer surgery, we employed extreme gradient boosting classifier, multilayer perceptron, and logistic regression models. Prolonged postoperative length of stay for cancer was defined as bed-days of the group of patients who accounted for the top 50% of the distribution of bed-days by cancer type.

RESULTS

In the prediction of prolonged length of stay after cancer surgery, extreme gradient boosting classifier models demonstrated excellent performance for kidney and bladder cancer surgeries (area under the receiver operating characteristic curve [AUC] >0.85). A moderate performance (AUC 0.70-0.85) was observed for stomach, breast, colon, thyroid, prostate, cervix uteri, corpus uteri, and oral cancers. For stomach, breast, colon, thyroid, and lung cancers, with more than 4000 cases each, the extreme gradient boosting classifier model showed slightly better performance than the logistic regression model, although the logistic regression model also performed adequately. We identified risk variables for the prediction of prolonged postoperative length of stay for each type of cancer, and the importance of the variables differed depending on the cancer type. After we added operative time to the models trained on preoperative factors, the models generally outperformed the corresponding models using only preoperative variables.

CONCLUSIONS

A machine learning approach using EHRs may improve the prediction of prolonged length of hospital stay after primary cancer surgery. This algorithm may help to provide a more effective allocation of medical resources in cancer surgery.

Factors Affecting Central Node Metastasis and Metastatic Lymph Node Ratio in Papillary Thyroid Cancer

OBJECTIVE

Despite the growing evidence that metastatic lymph node ratio (MLNR) is a valuable predictor for the prognosis of papillary thyroid carcinoma, it has not yet been fully determined which factors give the ratio predictive value independent of the number of metastatic lymph nodes (MLNs).

STUDY DESIGN

Retrospective cohort study.

SETTING

A comprehensive cancer center.

METHODS

Recurrence and clinicopathologic factors were analyzed in 2409 patients with papillary thyroid carcinoma who underwent total thyroidectomy and central node dissection.

RESULTS

Cutoff values of MLNs ≥2 and MLNR ≥28.2% increased the recurrence risk (hazard ratio [95% CI], 9.97 [4.73-21.0] and 11.4 [5.53-23.3], respectively). Younger age, male sex, multifocality, tumor size, lymphatic and vascular invasion, and gross extrathyroidal extension positively correlated with MLN and MLNR (all P < .05). Meanwhile, lymphocytic thyroiditis negatively correlated with MLNR in female patients (P < .001), by increasing total lymph node yields as compared with papillary thyroid carcinoma without lymphocytic thyroiditis. In multivariate analysis, younger age, tumor size, and lymphatic invasion remained significant in male and female patients for MLN and MLNR; lymphocytic thyroiditis was also significantly correlated with MLNR in female patients.

CONCLUSION

Our study demonstrates that MLN and MLNR are independently observed prognostic markers for tumor recurrence. However, lymphocytic thyroiditis in female patients seems to have lower MLNR by increasing total lymph node yields. In light of their association, a different cutoff for MLNR needs to be applied according to the presence or absence of underlying lymphocytic thyroiditis in the use of MLNR for predicting the recurrence.

LEVEL OF EVIDENCE

4.

Limitations of Deep Learning Attention Mechanisms in Clinical Research: Empirical Case Study Based on the Korean Diabetic Disease Setting

Background

Despite excellent prediction performance, noninterpretability has undermined the value of applying deep-learning algorithms in clinical practice. To overcome this limitation, attention mechanism has been introduced to clinical research as an explanatory modeling method. However, potential limitations of using this attractive method have not been clarified to clinical researchers. Furthermore, there has been a lack of introductory information explaining attention mechanisms to clinical researchers.

Objective

The aim of this study was to introduce the basic concepts and design approaches of attention mechanisms. In addition, we aimed to empirically assess the potential limitations of current attention mechanisms in terms of prediction and interpretability performance.

Methods

First, the basic concepts and several key considerations regarding attention mechanisms were identified. Second, four approaches to attention mechanisms were suggested according to a two-dimensional framework based on the degrees of freedom and uncertainty awareness. Third, the prediction performance, probability reliability, concentration of variable importance, consistency of attention results, and generalizability of attention results to conventional statistics were assessed in the diabetic classification modeling setting. Fourth, the potential limitations of attention mechanisms were considered.

Results

Prediction performance was very high for all models. Probability reliability was high in models with uncertainty awareness. Variable importance was concentrated in several variables when uncertainty awareness was not considered. The consistency of attention results was high when uncertainty awareness was considered. The generalizability of attention results to conventional statistics was poor regardless of the modeling approach.

Conclusions

The attention mechanism is an attractive technique with potential to be very promising in the future. However, it may not yet be desirable to rely on this method to assess variable importance in clinical settings. Therefore, along with theoretical studies enhancing attention mechanisms, more empirical studies investigating potential limitations should be encouraged.

Association among Body Mass Index, Genetic Variants of FTO, and Thyroid Cancer Risk: A Hospital-Based Case-Control Study of the Cancer Screenee Cohort in Korea

Purpose

Obesity has been determined to be associated with fat mass and obesity-associated (FTO) gene and thyroid cancer risk. However, the effect of combined interactions between obesity and the FTO gene on thyroid cancer needs further investigation. This study aimed to examine whether interactions between body mass index (BMI) and the FTO gene are associated with an increased risk of thyroid cancer.

Materials and Methods

A total of 705 thyroid cancer cases and 705 sex- and age-matched normal controls were selected from the Cancer Screenee Cohort in National Cancer Center, Korea. A conditional logistic regression model was used to calculate the odds ratios (ORs) and 95% confidence intervals (CIs) for the measure of associations and the combined effect of BMI and FTO gene on thyroid cancer.

Results

BMI was associated with an increased risk of thyroid cancer in subclasses of overweight (23–24.9 kg/m²; adjusted OR, 1.50; 95% CI, 1.12 to 2.00) and obese (≥ 25 kg/m²) (adjusted OR, 1.62; 95% CI, 1.23 to 2.14). There were positive associations between the FTO genetic variants rs8047395 and rs8044769 and an increased risk of thyroid cancer. Additionally, the combination of BMI subclasses and FTO gene variants was significantly associated with thyroid cancer risk in the codominant (rs17817288), dominant (rs9937053, rs12149832, rs1861867, and rs7195539), and recessive (rs17817288 and rs8044769) models.

Conclusion

Findings from this study identified the effects of BMI on thyroid cancer risk among individuals carrying rs17817288, rs9937053, rs12149832, rs1861867, rs7195539, and rs8044769, whereas the effects of BMI may be modified according to individual characteristics of other FTO variants.

Screening Model for Estimating Undiagnosed Diabetes among People with a Family History of Diabetes Mellitus: A KNHANES-Based Study

A screening model for estimating undiagnosed diabetes mellitus (UDM) is important for early medical care. There is minimal research and a serious lack of screening models for people with a family history of diabetes (FHD), especially one which incorporates gender characteristics. Therefore, the primary objective of our study was to develop a screening model for estimating UDM among people with FHD and enable its validation. We used data from the Korean National Health and Nutrition Examination Survey (KNHANES). KNAHNES (2010-2016) was used as a developmental cohort (n = 5939) and was then evaluated in a validation cohort (n = 1047) KNHANES (2017). We developed the screening model for UDM in male (SMM), female (SMF), and male and female combined (SMP) with FHD using backward stepwise logistic regression analysis. The SMM and SMF showed an appropriate performance (area under curve (AUC) = 76.2% and 77.9%) compared with SMP (AUC = 72.9%) in the validation cohort. Consequently, simple screening models were developed and validated, for the estimation of UDM among patients in the FHD group, which is expected to reduce the burden on the national health care system.

Long Work Hours Are Associated with Hypothyroidism: A Cross-Sectional Study with Population-Representative Data

Background: Studies have highlighted the adverse effects of long work hours on workers' health; however, the association of long work hours with thyroid function has not been studied. This study aimed at assessing long work hours as a risk factor for thyroid dysfunction. Methods: This cross-sectional study was based on data obtained from the Korea National Health and Nutrition Examination Survey conducted from 2013 to 2015. A total of 2160 adults who worked 36-83 hours per week were included. Thyroid function was defined based on the population thyroid-stimulating hormone reference ranges, after excluding individuals with positive results for thyroid peroxidase antibody. The association between work hours and thyroid function was confirmed via multinomial logistic regression. Results: Hypothyroidism was more prevalent among those with longer work hours (3.5% vs. 1.4% for 53-83 and 36-42 work hours per week, respectively). Individuals who worked longer hours had an increased odds for hypothyroidism (odds ratio 1.46, confidence interval 1.12 - 1.90, per 10-hour increase in work hours per week), after adjustment for age, sex, body mass index, urine iodine concentration, smoking status, work schedule, and socioeconomic status. The association between work hours and hypothyroidism was consistent in various subgroups stratified by sex or socioeconomic status. Conclusions: To our knowledge, this study is the first to show that long work hours are associated with hypothyroidism. Further large longitudinal studies are needed to clarify causality.

A Phase II Multi-Center, Non-Randomized, Parallel Group, Non-Inferiority Study to Compare the Efficacy of No Radioactive Iodine Remnant Ablation to Remnant Ablation Treatment in Low- to Intermediate-Risk of Papillary Thyroid Cancer: The MOREthyroid Trial Protocol

BACKGROUND

Radioactive iodine (RAI) remnant ablation is recommended in patients with papillary thyroid cancer (PTC) and extrathyroidal extension or central lymph node metastasis. However, there exists little evidence about the necessity of remnant ablation in PTC patients with low- to intermediate-risk, those have been increasing in recent decades.

METHODS

This multicenter, prospective, non-randomized, parallel group clinical trial will enroll 310 eligible patients with low- to intermediate-risk of thyroid cancer. Inclusion criteria are patients who recently underwent total thyroidectomy for PTC with 3 or less tumors of size 1≤ to ≤2 cm with no microscopic extension and N0/x, or size ≤2 cm with microscopic extension and/or N1a (number of lymph node ≤3, size of tumor foci ≤0.2 cm, and lymph node ratio &lt;0.4). Patients choose to undergo RAI ablation (131I, dose 1.1 GBq) or diagnostic whole-body scan (DxWBS) (131I or 123I, dose 0.074 to 0.222 GBq), followed by subsequent measurement of stimulated thyroglobulin (sTg) within 1 year. Survey for quality of life (QOL) will be performed at baseline and at 1 year after follow-up. The total enrollment period is 5 years, and patients will be followed up for 1 year. The primary endpoint is the non-inferiority of surgery alone to surgery with ablation in terms of biochemical remission (BCR) rate (sTg ≤2 ng/mL) without evidence of structural recurrence. The secondary endpoint was the difference of QOL.

CONCLUSION

This study will evaluate whether surgery alone achieves similar BCR and improved QOL compared to RAI ablation in patients with low- to intermediate-risk PTC within 1 year.

Diagnosis and Treatment of Growth Hormone Deficiency: A Position Statement from Korean Endocrine Society and Korean Society of Pediatric Endocrinology

Growth hormone (GH) deficiency is caused by congenital or acquired causes and occurs in childhood or adulthood. GH replacement therapy brings benefits to body composition, exercise capacity, skeletal health, cardiovascular outcomes, and quality of life. Before initiating GH replacement, GH deficiency should be confirmed through proper stimulation tests, and in cases with proven genetic causes or structural lesions, repeated GH stimulation testing is not necessary. The dosing regimen of GH replacement therapy should be individualized, with the goal of minimizing side effects and maximizing clinical improvements. The Korean Endocrine Society and the Korean Society of Pediatric Endocrinology have developed a position statement on the diagnosis and treatment of GH deficiency. This position statement is based on a systematic review of evidence and expert opinions.

Aspirin Use Is Not Associated with Lower Thyroid Cancer Risk: A Nationwide Nested Case-Control Study

Background: While aspirin use is known to be associated with reduced incidence of various cancer types, it is unclear whether this benefit extends to thyroid cancer. We aimed to evaluate the association between aspirin use and thyroid cancer development. Methods: This nested case-control study used nationwide data from the Korean National Health Insurance Service-National Sample Cohort 2002-2015. In total, 4547 individuals with newly developed thyroid cancer were matched with 13,641 controls based on age, sex, and follow-up period. Odds ratios (ORs) and 95% confidence intervals (CIs) for thyroid cancer development according to aspirin use were analyzed using a multivariable conditional logistic regression model. Results: The number of days for which patients with thyroid cancer used aspirin (the proportions of no use, <30 days/year, 30-90 days/year, and ≥90 days/year were 93.03%, 6.51%, 0.31%, and 0.15%, respectively) was comparable with that of the controls (p = 0.371, chi-squared test). The risk of thyroid cancer development was not associated with the duration of aspirin use (ORs [CI] for aspirin use <30 days/year, 30-90 days/year, and ≥90 days/year were 1.11 [0.96-1.28], 1.01 [0.54-1.88], and 1.23 [0.50-3.06], respectively, compared with no use) after adjusting for body mass index, smoking status, hypertension, Charlson comorbidity index, and number of outpatient visits per year. In addition, subgroup analyses stratified by age, sex, and follow-up duration did not reveal any significant association between aspirin use and thyroid cancer. Conclusions: Our findings suggest that even extended aspirin use may not impact the prevention or onset of thyroid cancer.

0935 Association Between Chronotype, Sleep Duration, Weekend Catch-Up Sleep, and Depression Among Korean High School Students

Introduction

The present study aimed to examine the association between chronotype, sleep duration, weekend catch-up sleep (CUS) duration, and depression among Korean high school students.

Methods

A total of 8,565 high school students who were analyzed from 15 nationwide districts in South Korea completed an online self-report questionnaire. Depressive mood was assessed using the Korean version of the Beck Depression Inventory. The following sleep characteristics were assessed: weekday and weekend sleep durations, weekend CUS duration, chronotype, perceived sufficiency of sleep, self-reported snoring and sleep apnea, daytime sleepiness, and sleep environment. Age, sex, body mass index, number of private classes, and proneness to internet addiction were also measured. Logistic regression analysis was conducted to compute odds ratios for the association between depression and sleep characteristics, after controlling for relevant covariates.

Results

The prevalence of depression (BDI ≥ 16) was 1,794 (20.9%). In the analyses of multivariate logistic regression, the late chronotype (odds ratio [OR], 1.71; 95% CI, 1.47-1.99), female (OR, 2.24; 95% CI, 1.99-2.53), underweight (OR, 1.27; 95% CI, 1.02-1.57) and obesity (OR, 1.41; 95% CI, 1.13-1.75), weekday sleep duration (OR, 0.86; 95% CI, 0.81-0.91), weekend CUS duration ≥ 2 hours (OR, 0.68; 95% CI, 0.55-0.85), ESS (OR, 1.08; 95% CI, 1.07-1.10), much (OR, 2.15; 95% CI, 1.63-2.84) and insufficient (OR, 1.71; 95% CI, 1.46-2.01) perceived sleep, snoring (OR, 1.27; 95% CI, 1.11-1.46) and witnessed apnea (OR, 2.10; 95% CI, 1.75-2.52), increased internet addiction (OR, 1.06; 95% CI, 1.05-1.06), high number of private education (OR, 0.76; 95% CI, 0.60-0.95), and poor sleep environment (OR, 1.86; 95% CI, 1.56-2.21) were associated with depression.

Conclusion

Eveningness preference, insufficient weekday sleep duration, short weekend CUS duration, and self-reported snoring and sleep apnea were associated with an increased risk for depression.

Support

 

OR28-06 Assessment of Long Term Quality of Life According to Treatment Options in Low Risk Papillary Thyroid Microcarcinoma Patients - Active Surveillance or Immediate Surgery, (A Follow up Interim Analysis of Maestro)

Background: The Multicenter Prospective Cohort Study of Active Surveillance on Papillary Thyroid Microcarcinoma (MAeSTro) started in June 2016. As a follow-up study of comparing the quality of life (QoL) of the active surveillance (AS) and immediate surgery (OP) groups at 8 months (9.3±4.8 and 7.1±4.2 months, respectively), here we aimed to compare the QoL between the AS and OP groups after 18 months (22.8±4.0 and 22.3±4.3 months, respectively) of follow-up.

Methods: QoL of 108 participants who chose AS, 101 who underwent OP, twelve who changed from AS to OP was evaluated using a thyroid‐specific QoL questionnaire at diagnosis and during follow‐up (median 23 months).

Results: The mean ages of the participants in the AS and OP groups were 47.7±11.0 and 45.1±10.0 years (p=0.075), respectively. At baseline, better physical (8.2±1.4 vs. 7.6±1.8, p=0.032), psychological (7.4±1.2 vs. 6.7±1.6, p=0.010), and total health (7.4±1.0 vs. 6.7±1.3, p=0.005) were observed in the AS group than in the OP group. After a mean follow up of 22.7±4.2 months, better physical (8.1±1.5 vs. 7.4±1.7, p=0.008), psychological (7.7±1.3 vs. 7.0±1.5, p=0.002), and total health (7.5±1.2 vs. 6.8±1.3, p=0.001) were observed in the AS group than in the OP group, whereas spiritual health was comparable between the two groups: compared with the AS group, the OP group experienced more alterations in appetite, sleep, menstrual cycle, voice, motor skill, weight, appearance, cold or heat tolerance, and body swelling. Furthermore, better QOL scores were observed in the AS group in self-concept, personal relationships, sexual life, work motivation, productivity and quality of work, feeling of isolation, driving, doing household chores, preparing meals and doing leisure activities after long term follow up.

Conclusion: Patients who underwent AS had better QOL even after long term follow up. Low risk papillary thyroid microcarcinomas do not influence survival, however surgery related deterioration of QOL lasted long and did not improve even in late post-operative stages when patients were fully recovered from surgery.

Keywords: Quality of life; papillary thyroid microcarcinoma; active surveillance; immediate surgery

SUN-417 Long Working Hours Are Associated with Hypothyroidism: A Cross-Sectional Study with Population-Representative Data

Background: Studies have highlighted the adverse effects of long working hours on workers’ health; however, the association of long working hours with thyroid function has not been studied. This study aimed to assess long working hours as a risk factor for thyroid dysfunction.

Methods: This cross-sectional study was based on data obtained from the Korea National Health and Nutrition Examination Survey conducted from 2013 to 2015. A total of 2,160 adults who worked 36–83 hours per week were included. Thyroid function was defined based on the population thyroid-stimulating hormone reference ranges, after excluding individuals with positive results for thyroid peroxidase antibody. The association between working hours and thyroid function was confirmed via multinomial logistic regression.

Results: Hypothyroidism was more prevalent among those with longer working hours (3·5% vs. 1·4% for 53–83 and 36–42 working hours per week, respectively). Individuals who worked longer hours had an increased odds for hypothyroidism (odds ratio 1·46, 95% confidence interval 1·12−1·90, per 10 hour increase in working hours per week), after adjustment for age, sex, body mass index, urine iodine concentration, smoking status, shift work, and socioeconomic characteristics such as occupation, income level, and educational attainment. The association between working hours and hypothyroidism was consistent in various subgroups stratified by sex or socioeconomic characteristics.

Conclusions: To our knowledge, this study is the first to show that long working hours are associated with hypothyroidism. Our findings suggest that appropriate monitoring and treatment of hypothyroidism are necessary among individuals who work long hours.

Incidence of Diabetes After Cancer Development: A Korean National Cohort Study

Importance

Diabetes is an established risk factor for developing cancer. A limited body of evidence also suggests that cancer can increase the risk of developing new cases of diabetes, but the evidence is inconclusive.

Objective

To evaluate whether the development of cancer is associated with increasing risk of subsequent diabetes.

Design, Setting, and Participants

This cohort study included a nationally representative sample of the Korean general population observed for up to 10 years (January 1, 2003, to December 31, 2013). A total of 524 089 men and women 20 to 70 years of age without diabetes and with no history of cancer at baseline were included.

Exposures

Incident cancer (time-varying exposure).

Main Outcomes and Measures

Incident type 2 diabetes using insurance claim codes.

Results

During 3 492 935.6 person-years of follow-up (median follow-up, 7.0 years) in 494 189 individuals (50.0% female; mean [SD] age, 41.8 [12.5] years), 15 130 participants developed cancer and 26 610 participants developed diabetes. After adjustment for age, sex, precancer diabetes risk factors, metabolic factors, and comorbidities, the hazard ratio (HR) for diabetes associated with cancer development was 1.35 (95% CI, 1.26-1.45; P < .001). The excess risk for diabetes was highest in the first 2 years after cancer diagnosis, but it remained elevated throughout follow-up. By cancer type, development of pancreatic (HR, 5.15; 95% CI, 3.32-7.99), kidney (HR, 2.06; 95% CI, 1.34-3.16), liver (HR, 1.95; 95% CI, 1.50-2.54), gallbladder (HR, 1.79; 95% CI, 1.08-2.98), lung (HR, 1.74; 95% CI, 1.34-2.24), blood (HR, 1.61; 95% CI, 1.07-2.43), breast (HR, 1.60; 95% CI, 1.27-2.01), stomach (HR, 1.35; 95% CI, 1.16-1.58), and thyroid cancer (HR, 1.33; 95% CI, 1.12-1.59) was associated with a significantly increased risk of diabetes.

Conclusions and Relevance

In this large Korean cohort, cancer development increased the risk of subsequent diabetes. These data provide evidence that cancer is associated with an increased risk of diabetes in cancer survivors independent of traditional diabetes risk factors. Physicians should remember that patients with cancer develop other clinical problems, such as diabetes, with higher frequency than individuals without cancer, and should consider routine diabetes screening in these patients.

Longitudinal Assessment of Quality of Life According to Treatment Options in Low-Risk Papillary Thyroid Microcarcinoma Patients: Active Surveillance or Immediate Surgery (Interim Analysis of MAeSTro)

Background: In this ongoing multicenter prospective cohort study on active surveillance (AS) in low-risk papillary thyroid microcarcinoma (PTMC), we aimed to compare the quality of life (QoL) of participants based on their choice of treatment, that is, AS or immediate surgery (OP). Methods: QoL of 203 participants who chose AS and 192 participants who underwent OP was evaluated using a thyroid-specific QoL questionnaire at diagnosis and during follow-up (median 8 months). Results: The mean ages of the participants in the AS and OP groups were 47.3 ± 11.7 and 45.6 ± 10.5 years (p = 0.138), respectively, and the mean tumor sizes were 5.7 ± 1.6 and 6.5 ± 2.1 mm (p = 0.065), respectively. At baseline, significantly better psychological health (7.1 ± 1.3 vs. 6.8 ± 1.6, p = 0.023) and overall health (6.8 ± 1.2 vs. 6.5 ± 1.3, p = 0.018) were observed in the AS group than in the OP group. During follow-up, significantly better physical (7.9 ± 1.1 vs. 7.4 ± 1.2, p < 0.001), psychological (7.4 ± 1.3 vs. 6.9 ± 1.6, p = 0.004), and overall health (6.9 ± 1.0 vs. 6.5 ± 1.1, p = 0.002) were observed in the AS group than in the OP group, whereas spiritual health was comparable between the two groups. Compared with the AS group, the OP group experienced more fatigue, changes in voice and appearance, less satisfaction, and low fear of recurrence. The self-assessed financial burden was similar at baseline and follow-up in both groups. Conclusion: The QoL of PTMC patients is different according to the type of treatment. Better psychological health at baseline and physical and psychological health at follow-up were observed in the AS group than in the OP group. However, studies with longer follow-up periods are needed.

Tumor doubling time predicts response to sorafenib in radioactive iodine-refractory differentiated thyroid cancer

Sorafenib has emerged as an effective therapeutic option for radioactive iodine (RAI)-refractory, locally advanced or metastatic differentiated thyroid cancer (DTC). We investigated the efficacy and safety of sorafenib treatment in a real-world setting and unveil predictive markers of responsiveness to sorafenib. The treatment response, progression-free survival (PFS), overall survival, and adverse events (AEs) of sorafenib-treated RAI-refractory, locally advanced or metastatic DTC patients at three institutes were retrospectively reviewed, and their tumor doubling time was calculated by three investigators. Total eighty-five patients were treated with sorafenib, and seven patients discontinued sorafenib due to AEs before the first tumor assessment. The median PFS was 14.4 months, and the objective response rate was 10.3% in 78 patients who were able to evaluate the tumor response. Age, sex, histologic type, tumor location, RAI avidity, or the presence of FDG-PET uptake did not affect PFS. However, smaller tumor size (≤1.5 cm) of the target lesions in lung showed better PFS (hazard ratio [HR] 0.39, p = 0.01), and tumors with the shortest doubling time (≤6 months) had worse outcome (HR 2.70, p < 0.01). Because of AEs, dose reductions or drug interruptions were required in 64% of patients, and eventually, 23% of patients discontinued sorafenib permanently. The most common AE was hand-foot skin reaction (HFSR). Patients with severe HFSR showed better PFS, but there were no statistical significance (HR 0.65, p = 0.05). In conclusion, small tumor size and long doubling time of each target lesion can be a prognostic marker to predict the responsiveness to sorafenib in RAI-refractory DTC patients.

Genome-Wide Association Study Reveals Distinct Genetic Susceptibility of Thyroid Nodules From Thyroid Cancer

CONTEXT

Thyroid nodules are very common, and 7% to 15% of them are diagnosed as thyroid cancer. However, the inherited genetic risk factors for thyroid nodules and their associations with thyroid cancer remain unknown.

OBJECTIVE

To identify the genetic variants associated with susceptibility to thyroid nodules in comparison with thyroid cancer.

DESIGN AND SETTING

We performed a three-stage genome-wide association study for thyroid nodules. The discovery stage involved a genome-wide scan of 811 subjects with thyroid nodules and 691 subjects with a normal thyroid from a population-based cohort. Replication studies were conducted in an additional 1981 cases and 3100 controls from the participants of a health checkup. We also performed expression quantitative trait loci analysis of public data.

RESULTS

The most robust association was observed in TRPM3 (rs4745021) in the joint analysis (OR, 1.26; P = 6.12 × 10-8) and meta-analysis (OR, 1.28; P = 2.11 × 10-8). Signals at MBIP/NKX2-1 were replicated but did not reach genome-wide significance in the joint analysis (rs2415317, P = 4.62 × 10-5; rs944289, P = 8.68 × 10-5). The expression quantitative trait loci analysis showed that TRPM3 expression was associated with the rs4745021 genotype in thyroid tissues.

CONCLUSIONS

To the best of our knowledge, we have performed the first genome-wide association study of thyroid nodules and identified a susceptibility locus associated with thyroid nodules, suggesting that thyroid nodules have a genetic predisposition distinct from that of thyroid cancer.

Genetic variations in TAS2R3 and TAS2R4 bitterness receptors modify papillary carcinoma risk and thyroid function in Korean females

Type 2 taste receptors (T2Rs, TAS2Rs) mediate bitterness perception and are involved in diverse defence mechanisms in extraoral tissues. The thyrocyte-expressed T2Rs control thyroid hormone production, and this regulatory role may be associated with susceptibility to thyroid diseases. This study examined whether the variations in TAS2Rs modify the risk of papillary thyroid carcinoma (PTC) and whether such T2R-related PTC risk is associated with genetically modified thyroid function. We conducted a case-control study with 763 Korean females, including 250 PTC cases. Seventy-three single-nucleotide polymorphisms in 13 TAS2R genes and the pre-diagnosis levels of 4 thyroid-related functional markers [total triiodothyronine (TT3), free thyroxine, thyroid-stimulating hormone and thyroglobulin] were analysed. Individuals with TAS2R3/4 CC haplotype (rs2270009 and rs2234001) were at a lower risk for PTC than those with the remaining haplotypes (odds ratio = 0.59, 95% confidence interval: 0.36-0.97). Furthermore, TT3 levels were significantly reduced for TAS2R3/4 CC haplotype carriers compared with other haplotype carriers (p = 0.005). No other genetic variants exhibited critical associations with the PTC phenotype and biomarkers. In summary, genetic variations in T2R3/4 bitterness receptors may modify the PTC risk, and the genetically modified thyroid hormone level by those variations may be linked with the PTC-T2Rs association.

Corrigendum: Author's Name Correction. Study Protocol of Multicenter Prospective Cohort Study of Active Surveillance on Papillary Thyroid Microcarcinoma (MAeSTro)

This corrects the article on p. 278 in vol. 33, PMID: 29947183.

Relation of Subclinical Hypothyroidism is Associated With Cardiovascular Events and All-Cause Mortality in Adults With High Cardiovascular Risk

The aim of this study was to determine the association between subclinical hypothyroidism and cardiovascular (CVD) events, and mortality using the atherosclerotic CVD risk score. We carried out an observational study in a prospective cohort that was followed up for 12 years. The study included 3,021 participants aged ≥ 40 years at baseline from the Ansung cohort, part of the Korean Genome and Epidemiology Study. Cox regression models were constructed to evaluate the hazards ratio (HR) and 95% confidence interval (CI) for all-cause mortality and CVD events in groups classified according to thyroid status. Subgroup analysis was performed with a cut-off age of 65 years or 7.5% of the 10-year atherosclerotic CVD risk score. The subclinical hypothyroidism group in the highest quartile of thyroid-stimulating hormone (>6.57 mIU/L) had a significantly increased risk of all-cause mortality (HR 2.12, 95% CI 1.27 to 3.56) and CVD events (HR 1.92, 95% CI 1.21 to 3.04) compared with euthyroid participants. Subgroup analysis by CVD risk revealed that participants with high CVD risk only had a high risk of all-cause mortality (HR 2.18, 95% CI 1.22 to 3.87) and CVD events (HR 2.42, 95% CI 1.35 to 4.33). Further analysis showed that participants aged <65 years with high CVD risk had the highest risk of all-cause mortality (HR 3.50, 95% CI 1.50 to 8.16) and CVD events (HR 3.37, 95% CI 1.46 to 9.57). Our results demonstrated that high thyroid-stimulating hormone levels were associated with a greater risk of mortality and new CVD risks, particularly among subjects with high CVD risk.

Abstract 5269: Body mass index may not have causal association with thyroid cancer risk: A Mendelian randomization study

Background: Thyroid cancer (TC) is one of the endocrine tumors of which incidence rates have shown an upward trend worldwide. Obesity, another endemic health issue, has been recently reported in the association with increased TC risk. We attempted to examine if there is a causal association between body mass index (BMI) and TC using a Mendelian randomization approach.

Methods: Total 17,935 healthy individuals from the Korean Genome Epidemiology Study and 1,214 TC cases from National Cancer Center, Korea, and Seoul National University Hospital were selected with age, sex, BMI, and genetic information. Based on the thirteen previously reported single nucleotide polymorphisms associated with BMI, we constructed a genetic risk score (GRS) as a genetic instrumental variable (IV) representing BMI independent of possible confounding. IV analysis was performed using the ratio (or, Wald) method to test causal association.

Results: The odds of TC were 2.6 times higher in females than males. The cases were younger than the controls. The F-statistic from the regression of BMI on BMI GRS (IV) was 157.2 (usually, F larger than 10 indicates a strong and valid IV), and the IV explained 1.10% of the phenotypic variance for BMI. From IV analysis, genetically instrumented BMI was not associated with TC risk (causal odds ratio per 1kg/m2 increase in BMI 0.98 [0.79 - 1.20 95% confidence interval]).

Conclusion: Our analysis suggests that positive association between obesity and TC risk repeatedly reported from several meta-analyses may be null. Further investigation is needed as the incidence rates differ in different ethnicity.

Citation Format: Jeongseon Kim, Soo Ji Lee, Quy N. Nguyen, Jeonghee Lee, Eun Kyung Lee, Yul Hwangbo, Joohon Sung. Body mass index may not have causal association with thyroid cancer risk: A Mendelian randomization study [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 5269.

Study Protocol of Multicenter Prospective Cohort Study of Active Surveillance on Papillary Thyroid Microcarcinoma (MAeSTro)

BACKGROUND

The ongoing Multicenter Prospective Cohort Study of Active Surveillance on Papillary Thyroid Microcarcinoma (MAeSTro) aims to observe the natural course of papillary thyroid microcarcinoma (PTMC), develop a protocol for active surveillance (AS), and compare the long-term prognosis, quality of life, and medical costs between the AS and immediate surgery groups.

METHODS

This multicenter prospective cohort study of PTMC started in June 2016. The inclusion criteria were suspicious of malignancy or malignancy based on fine needle aspiration or core needle biopsy, age of ≥18 years, and a maximum diameter of ≤1 cm. If there was no major organ involvement, no lymph node/distant metastasis, and no variants with poor prognosis, the patients were explained of the pros and cons of immediate surgery and AS before selecting AS or immediate surgery. Follow-up visits (physical examination, ultrasonography, thyroid function, and questionnaires) are scheduled every 6 months during the first 2 years, and then every 1 year thereafter. Progression was defined as a maximum diameter increase of ≥3, ≥2 mm in two dimensions, suspected organ involvement, or lymph node/distant metastasis.

RESULTS

Among 439 enrolled patients, 290 patients (66.1%) chose AS and 149 patients (33.9%) chose immediate surgery. The median follow-up was 6.7 months (range, 0.2 to 11.9). The immediate surgery group had a larger maximum tumor diameter, compared to the AS group (7.1±1.9 mm vs. 6.6±2.0 mm, respectively; P=0.014).

CONCLUSION

The results will be useful for developing an appropriate PTMC treatment policy based on its natural course and risk factors for progression.

Genome-Wide Association Studies of Autoimmune Thyroid Diseases, Thyroid Function, and Thyroid Cancer

Thyroid diseases, including autoimmune thyroid diseases and thyroid cancer, are known to have high heritability. Family and twin studies have indicated that genetics plays a major role in the development of thyroid diseases. Thyroid function, represented by thyroid stimulating hormone (TSH) and free thyroxine (T4), is also known to be partly genetically determined. Before the era of genome-wide association studies (GWAS), the ability to identify genes responsible for susceptibility to thyroid disease was limited. Over the past decade, GWAS have been used to identify genes involved in many complex diseases, including various phenotypes of the thyroid gland. In GWAS of autoimmune thyroid diseases, many susceptibility loci associated with autoimmunity (human leukocyte antigen [HLA], protein tyrosine phosphatase, non-receptor type 22 [PTPN22], cytotoxic T-lymphocyte associated protein 4 [CTLA4], and interleukin 2 receptor subunit alpha [IL2RA]) or thyroid-specific genes (thyroid stimulating hormone receptor [TSHR] and forkhead box E1 [FOXE1]) have been identified. Regarding thyroid function, many susceptibility loci for levels of TSH and free T4 have been identified through genome-wide analyses. In GWAS of differentiated thyroid cancer, associations at FOXE1, MAP3K12 binding inhibitory protein 1 (MBIP)-NK2 homeobox 1 (NKX2-1), disrupted in renal carcinoma 3 (DIRC3), neuregulin 1 (NRG1), and pecanex-like 2 (PCNXL2) have been commonly identified in people of European and Korean ancestry, and many other susceptibility loci have been found in specific populations. Through GWAS of various thyroid-related phenotypes, many susceptibility loci have been found, providing insights into the pathogenesis of thyroid diseases and disease co-clustering within families and individuals.

Favorable glycemic response after pancreatoduodenectomy in both patients with pancreatic cancer and patients with non-pancreatic cancer

Diabetes mellitus (DM) is prevalent in patients with pancreatic cancer and tends to improve after tumor resection. However, the glycemic response of non-pancreatic cancer patients after surgery has not been examined in detail. We aimed to investigate the changes in glucose metabolism in patients with pancreatic cancer or non-pancreatic cancer after pancreatoduodenectomy (PD).We prospectively enrolled 48 patients with pancreatic cancer and 56 patients with non-pancreatic cancer, who underwent PD. Glucose metabolism was assessed with fasting glucose, glycated hemoglobin (HbA1c), plasma C-peptide and insulin, quantitative insulin check index (QUICKI), and a homeostatic model assessment of insulin resistance (HOMA-IR) and β cell (HOMA-β) before surgery and 6 months after surgery. Patients were divided into 2 groups: "improved" and "worsened" postoperative glycemic response, according to the changes in HbA1c and anti-diabetic medication. New-onset DM was defined as diagnosis of DM ≤ 2 years before PD, and cases with DM diagnosis >2 years preceding PD were described as long-standing DM.After PD, insulin resistance (IR), as measured by insulin, HOMA-IR and QUICKI, improved significantly, although C-peptide and HOMA-β decreased. At 6 months after PD, new-onset DM patients showed improved glycemic control in both pancreatic cancer patients (75%) and non-pancreatic cancer patients (63%). Multivariate analysis showed that long-standing DM was a significant predictor for worsening glucose control (odds ratio = 4.01, P = .017).Favorable glycemic control was frequently observed in both pancreatic cancer and non-pancreatic cancer after PD. PD seems to contribute improved glucose control through the decreased IR. New-onset DM showed better glycemic control than long-standing DM.

Interaction between alcohol consumption and methylenetetrahydrofolate reductase polymorphisms in thyroid cancer risk: National Cancer Center cohort in Korea

The effect of alcohol intake on thyroid cancer is unestablished, and its interaction effects with genetic susceptibility are unclear. In this case-control study, the relationship among alcohol intake, the methylenetetrahydrofolate reductase (MTHFR) gene, and thyroid cancer risk has been evaluated. In total, 642 cases and 642 controls of Korean origin were included, and the genetic variants C677T and A1298C of the MTHFR gene were analysed. The interactions between alcohol-consumption behaviour and genetic variants were analysed with a likelihood ratio test, wherein a multiplicative interaction term was added to a logistic regression model. There was an independent association between the C677T polymorphism and thyroid cancer risk but not for drinking history. For C677T C/C homozygotes, individuals with a history of alcohol consumption showed a protective OR (95% CI) of 0.42 (0.15–1.13) when never drinkers were used as the reference. However, this protective association was not observed among individuals with a T+ allele with an OR (95% CI) of 1.27 (0.89–1.82), showing different directions for the association between genotypes with a significant interaction (P_interaction = 0.009). Based on the genetic characteristics of individuals included, an interaction between alcohol intake and MTHFR C677T may modify the risk of thyroid cancer.

Genome-wide association and expression quantitative trait loci studies identify multiple susceptibility loci for thyroid cancer

Thyroid cancer is the most common cancer in Korea. Several susceptibility loci of differentiated thyroid cancer (DTC) were identified by previous genome-wide association studies (GWASs) in Europeans only. Here we conducted a GWAS and a replication study in Koreans using a total of 1,085 DTC cases and 8,884 controls, and validated these results using expression quantitative trait loci (eQTL) analysis and clinical phenotypes. The most robust associations were observed in the NRG1 gene (rs6996585, P=1.08 × 10⁻¹⁰) and this SNP was also associated with NRG1 expression in thyroid tissues. In addition, we confirmed three previously reported loci (FOXE1, NKX2-1 and DIRC3) and identified seven novel susceptibility loci (VAV3, PCNXL2, INSR, MRSB3, FHIT, SEPT11 and SLC24A6) associated with DTC. Furthermore, we identified specific variants of DTC that have different effects according to cancer type or ethnicity. Our findings provide deeper insight into the genetic contribution to thyroid cancer in different populations.

Thyroid cancer is the most common cancer in Korea but previous genome-wide association studies on risk loci have been conducted only in Europeans. Here the authors identify three previously reported loci and seven putatively new loci in the Korean population.

Abstract 1325: Genome-wide association study of thyroid nodule in Korean population

Thyroid nodule is very common. Several autopsy surveys reported that 30% or more of patients had thyroid nodule. However, inherited genetic risk factors for thyroid nodule remain unknown. Genome-wide association studies (GWAS) are widely used in human genetics to identify genes associated with various diseases. We aimed to find genetic factors for thyroid nodule and conducted case-control GWAS.

Objective: To identify genetic variants associated with susceptibility to thyroid nodules

Methods: We performed a two-stage GWAS for thyroid nodule. The discovery stage involved a genome-wide scan of 713 subjects with thyroid nodule and 591 subjects with normal thyroid from a population-based cohort. replication testing was conducted in an additional 600 cases and 600 controls from the participants of a health check-up.

Results In discovery stage, 21 candidate single nucleotide polymorphisms (SNP) in 20 loci including NKX2-1, ITGB1 and ZBTB25 were selected for replication. The strongest signal located in NKX2-1 (P = 9x10-7), which is known susceptibility locus for differentiated thyroid cancer. However, no SNP showed significant association in replication test. In joint analysis, no association signals reaching genome-wide significance (P &lt;5x10-8) were detected.

Conclusion GWAS for thyroid nodule have failed to identify susceptibility locus. Therefore, genetic effect for development of thyroid nodule could be negligible.

Citation Format: Eun Kyung Lee, Yul Hwangbo, Young Joo Park, Jong-Il Kim, Yuh-Seog Jung, Jun Sun Ryu. Genome-wide association study of thyroid nodule in Korean population [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 1325. doi:10.1158/1538-7445.AM2017-1325

Development and Evaluation of a Korean Version of a Thyroid-Specific Quality-of-Life Questionnaire Scale in Thyroid Cancer Patients

Purpose

The purpose of this study was to develop a Korean version of the self-reported thyroid-specific quality of life (QoL) questionnaire for thyroid cancer patients (KT-QoL), and to evaluate its reliability and validity.

Materials and Methods

Two hundred seventy-two patients who underwent thyroidectomy from January to December 2010 were recruited in this study. The original version of the thyroid QoL was translated into Korean and evaluated for its reliability and validity. Using the developed KT-QoL, the postoperative QoL was evaluated until postoperative 1 year.

Results

At the preoperative baseline, the item internal consistency (IIC) ranged from ‒0.19 to 0.76, with low IIC values for items 2, 17, and 27. Item discriminant validity ranged from 86% to 97%. These values were similar at the postoperative periods. The internal consistency reliability (Cronbach’s α) was high for all dimensions, ranging from 0.90 to 0.95. The test-retest reliability (intraclass correlation coefficient) was acceptable (0.74-0.82). The external validity examined by the correlation between the item 1j (voice changes) of KT-QoL and the voice handicap index-30 ranged from 0.51 to 0.75. Patients’ QoL scores decreased after surgery, which demonstrated the sensitivity of the questionnaire. The QoL scores in patients with lobectomy showed best QoL scores postoperatively and those with receiving radioactive iodine still showed decreased QoL scores along the postoperative periods.

Conclusion

These results demonstrate that KT-QoL is a valid instrument for evaluating QoL of Korean patients with thyroid cancer.