Cancer Risk in Graves Disease with Radioactive 131I Treatment: A Nationwide Cohort Study.

Radioactive 131I (RAI) therapy has potential effects for the treatment of Graves disease (GD). However, whether RAI therapy for GD increases cancer risk remains controversial in medicine and public health. We aimed to investigate whether the risk of cancer increases in patients with GD receiving RAI therapy compared with those who did not. Methods: We used the Korean National Health Insurance Service's National Health Information Database from 2004 to 2020 and defined GD as prescribing antithyroid drugs, RAI, or thyroidectomy as a treatment for GD (International Classification of Diseases, 10th revision, E05 group). We investigated the hazard ratios (HRs) of overall and site-specific cancers associated with RAI in patients with GD. Subsequent cancer was defined as a primary malignancy treated at least 1 y after RAI therapy. Results: In total, 10,737 patients with GD who received RAI therapy (7,193 women, 67.0%; mean age, 43.7 ± 13.4 y) were matched to 53,003 patients with GD who had never received RAI treatment (35,471 women, 66.9%; mean age, 43.8 ± 13.2 y) in a 1:4-5 ratio by age, sex, and health checkup data. The median follow-up duration was 8.7 y (interquartile range, 5.2-12.1 y), and the median cumulative RAI dose was 555 MBq (interquartile range, 370-630 MBq) in the RAI therapy group. During 2004-2020, the overall subsequent cancer rates were 5.66 and 5.84 per 1,000 person-years in the RAI and non-RAI groups, respectively, with an unadjusted HR of 0.97 (95% CI, 0.88-1.06); this remained at 0.96 (95% CI, 0.83-1.10) after adjustment for multiple clinical confounding factors. For cancer subtypes, the risk of leukemia was significantly increased, with an HR of 2.39 (95% CI, 1.17-4.91). However, a loss of statistical significance was observed after adjusting for confounding factors, which may be attributed to the limited number of absolute events. Moreover, cancer-specific mortality was not different between the RAI and the non-RAI groups, with an adjusted HR of 0.99 (95% CI, 0.66-1.47). Conclusion: This study identified that the overall cancer risk in patients with GD who received RAI therapy compared with those who did not was not significant in Korea. Further long-term studies are needed to determine the risks and advantages of RAI therapy in patients with GD.

Concurrent Subacute Thyroiditis and Graves' Disease After COVID-19: A Case Report.

There are many reports of subacute thyroiditis (SAT) that occurred after the coronavirus disease 2019 (COVID-19), but no such case has been reported in Korea. Moreover, the simultaneous occurrence of SAT and Graves' disease (GD) is rare. Here, we describe a patient who developed SAT and GD after the second episode of COVID-19. A 27-year-old woman with no known history of thyroid disease presented with fever, upper respiratory tract symptoms, and painful neck swelling. Thyroid function tests revealed thyrotoxicosis, and thyroid ultrasound showed heterogeneous echogenicity of enlarged thyroid glands. Her initial clinical presentation was consistent with SAT after viral infection, with typical neck tenderness and spontaneous improvement of thyrotoxicosis without antithyroid drug use. However, this case had some atypical features, such as an elevated thyroid-stimulating immunoglobulin level, relapse of thyrotoxicosis in short-term follow-up, and increased Tc-99m pertechnetate uptake, suggesting the coexistence of GD. About two months after methimazole (15 mg/day) was prescribed, she was lost to follow up again. We report the first case of unusual co-occurrence of SAT and GD following COVID-19.

Increased Risk of Type 2 Diabetes in Patients With Thyroid Cancer After Thyroidectomy: A Nationwide Cohort Study.

CONTEXT: Abnormal thyroid function after thyroidectomy and subsequent thyroid-stimulating hormone suppression can have detrimental effects on glucose homeostasis in patients with thyroid cancer. OBJECTIVE: To investigate whether thyroidectomy increases the risk of type 2 diabetes in patients with thyroid cancer and to explore the association between levothyroxine dosage and type 2 diabetes risk. METHODS: A retrospective population-based cohort study using the Korean National Health Insurance database. We included 36 377 thyroid cancer patients without known diabetes who underwent thyroidectomy between 2004 and 2013. Matched subjects with nonthyroid cancer were selected using 1:1 propensity score matching. The main outcome measure was newly developed type 2 diabetes mellitus. RESULTS: Patients with thyroid cancer who underwent thyroidectomy had a higher risk of developing type 2 diabetes mellitus than the matched controls (hazard ratio [HR] 1.43, 95% CI 1.39-1.47). Among patients with thyroid cancer, when the second quartile group (in terms of the mean levothyroxine dosage; 101-127 µg/day) was considered the reference group, the risk of type 2 diabetes mellitus increased in the first quartile (<101 µg/day; HR 1.45, 95% CI 1.36-1.54) and fourth quartile groups (≥150 µg/day; HR 1.37, 95% CI 1.29-1.45); meanwhile, the risk decreased in the third quartile group (128-149 µg/day; HR 0.91, 95% CI 0.85-0.97). CONCLUSION: Patients with thyroid cancer who underwent thyroidectomy were more likely to develop type 2 diabetes mellitus than the matched controls. There was a U-shaped dose-dependent relationship between the levothyroxine dosage and type 2 diabetes mellitus risk.

Risk of Diabetes in Patients with Long-Standing Graves' Disease: A Longitudinal Study.

BACKGROUND: The detrimental effects of excessive thyroid hormone on glucose metabolism have been widely investigated. However, the risk of diabetes in patients with long-standing hyperthyroidism, especially according to treatment modality, remains uncertain, with few longitudinal studies. METHODS: The risk of diabetes in patients with Graves' disease treated with antithyroid drugs (ATDs) for longer than the conventional duration (≥2 years) was compared with that in age-and sex-matched controls. The risk was further compared according to subsequent treatment modalities after a 24-month course of ATD: continuation of ATD (ATD group) vs. radioactive iodine ablation (RIA) group. RESULTS: A total of 4,593 patients were included. Diabetes was diagnosed in 751 (16.3%) patients over a follow-up of 7.3 years. The hazard ratio (HR) for diabetes, after adjusting for various known risk factors, was 1.18 (95% confidence interval [CI], 1.10 to 1.28) in patients with hyperthyroidism. Among the treatment modality groups, the RIA group (n=102) had a higher risk of diabetes than the ATD group (n=4,491) with HR of 1.56 (95% CI, 1.01 to 2.42). Further, the risk of diabetes increased with an increase in the ATD treatment duration (P for trend=0.019). CONCLUSION: The risk of diabetes was significantly higher in patients with long-standing Graves' disease than in the general population, especially in patients who underwent RIA and prolonged ATD treatment. Special attention to hyperglycemia during follow-up along with effective control of hyperthyroidism may be necessary to reduce the risk of diabetes in these patients.

Mutation in Genes Encoding Key Functional Groups Additively Increase Mortality in Patients with BRAFV600E-Mutant Advanced Papillary Thyroid Carcinoma.

The prognosis of BRAFV600E-mutant papillary thyroid carcinoma (PTC) ranges from indolent to highly aggressive courses. To better define the genetic diversity of this subtype, we evaluated the survival according to the presence of an additional mutation in genes encoding functional groups (FGs) in BRAFV600E-mutant advanced PTC patients. Targeted next-generation sequencing was performed in primary tumors of 50 BRAFV600E-mutant PTCs with distant metastasis or aggressive variants. The mutation in genes encoding FGs included alterations in histone methyltransferases, SWI/SNF subunit, and the PI3K/AKT/mTOR pathway. The primary outcome was overall survival (OS). Fifteen patients only had the BRAFV600E-mutation (group 1), 22 had BRAFV600E and mutation other than FGs (group 2), and 13 had BRAFV600E and FG mutation (group 3). OS was significantly lower in patients with FG mutations (p = 0.001) than those without, and group 3 patients had the worst survival (p = 0.004). OS significantly varied among none, one, or two FG mutation sites (p = 0.005). Presence of FG mutation was independently associated with increased mortality (hazard ratio 11.65, 95% confidence interval 1.39-97.58, p = 0.024). Coexistence of mutations in BRAFV600E and genes encoding FGs was associated with high mortality. Identification of FG mutation in BRAFV600E-mutant PTCs may be valuable in risk stratifying this subtype.

Long Working Hours and Risk of Nonalcoholic Fatty Liver Disease: Korea National Health and Nutrition Examination Survey VII.

Background: The global incidence of NAFLD is rising sharply due to various risk factors. As previous studies reported adverse health impact of long working hours on metabolic diseases, such as diabetes mellitus and obesity, it is plausible that NAFLD is also associated with working excessive hours. However, data regarding this issue is limited. Methods: In this cross-sectional study based on Korea National Health and Nutrition Examination Survey VII, 5,661 working adults without previous liver disease or heavy alcohol drinking habits were included. The subjects were categorized into three groups according to working hours: 36-42, 43-52, and 53-83 hours/week. NAFLD was defined using the hepatic steatosis index (HSI), which is a validated prediction model for determining NAFLD. Results: The prevalence of NAFLD (HSI ≥36) increased with longer working hours: 23.0%, 25.6%, and 30.6% in the 36-42, 43-52, and 53-83 hours/week group, respectively (p <0.001). Subjects who worked 53-83 hours/week had higher odds for NAFLD than those who worked the standard 36-42 hours/week (OR 1.23, 95% CI 1.02-1.50, p = 0.033) after adjusting for age, sex, body mass index, smoking, alcohol, exercise, diabetes mellitus, hypertension, serum triglyceride, and total cholesterol. This association was consistent across subgroups according to working schedule (daytime vs. shift workers) or occupation type (office vs. manual workers). In particular, the relationship between long working hours and NAFLD was pronounced in workers aged <60 years and in female workers. Conclusions: Long working hours was significantly associated with NAFLD. Further prospective studies are required to validate this finding with causal relationship.

Gender-Dependent Reference Range of Serum Calcitonin Levels in Healthy Korean Adults.

BACKGROUND: Serum calcitonin measurement contains various clinical and methodological aspects. Its reference level is wide and unclear despite sensitive calcitonin kits are available. This study aimed to identify the specific reference range in the healthy Korean adults. METHODS: Subjects were ≥20 years with available calcitonin (measured by a two-site immunoradiometric assay) data by a routine health checkup. Three groups were defined as all eligible subjects (group 1, n=10,566); subjects without self or family history of thyroid disease (group 2, n=5,152); and subjects without chronic kidney disease, autoimmune thyroid disease, medication of proton pump inhibitor/H2 blocker/steroid, or other malignancies (group 3, n=4,638). RESULTS: This study included 6,341 male and 4,225 female subjects. Males had higher mean calcitonin than females (2.3 pg/mL vs. 1.9 pg/mL, P<0.001) in group 1. This gender difference remained similar in groups 2 and 3. Calcitonin according to age or body mass index was not significant in both genders. Higher calcitonin in smoking than nonsmoking men was observed but not in women. Sixty-nine subjects had calcitonin higher than the upper reference limit (10 pg/mL) and 64 of them had factors associated with hypercalcitoninemia besides medullary thyroid cancer. Our study suggests the reference intervals for men who were non, ex-, current smokers, and women (irrespective of smoking status) as <5.7, <7.1, <7.9, and <3.6 pg/mL, respectively. CONCLUSION: Specific calcitonin reference range should be provided considering for sex and smoking status. Taking account for several factors known to induce hypercalcitoninemia can help interpret the gray zone of moderately elevated calcitonin.

Genetic Profiles of Aggressive Variants of Papillary Thyroid Carcinomas.

Aggressive variants of papillary thyroid carcinoma (PTC) have been described with increasing frequency and are associated with unfavorable clinical outcomes. However, limited data exist on the comprehensive genetic profile of these variants. We performed targeted next-generation sequencing in 36 patients with aggressive variants of PTC and compared it to PTC from The Cancer Genome Atlas (TCGA) project and poorly differentiated thyroid cancers (PDTCs)/anaplastic thyroid cancers (ATCs) from the Memorial Sloan Kettering Cancer Center (MSKCC). BRAF mutation was the most prevalent (89%) in aggressive variants of PTC compared to that in other thyroid cancers. RAS mutation was identified in one patient (3%), which was less frequent than in others. TERT promoter mutation (17%) ranged between that of PTCs (9%) and PDTCs (40%). Tumor suppressor genes, ZFHX3, TP53, and CHEK2, were mutated in 14%, 3%, and 6% of aggressive variants of PTC, respectively. The mutation rate of TP53 (3%) was significantly higher than that of PTCs (0.7%) and lower than that of ATCs (73%). Mutations in three functional groups, histone methyl transferases, SWI/SNF chromatin remodeling complex, and the PI3K/AKT/mTOR pathway, were present in 11%, 14%, and 11% of samples, respectively. In conclusion, aggressive variants of PTC had higher BRAF and lower NRAS mutation prevalence than other thyroid cancers. The prevalence of mutations in the TERT promoter, TP53, and genes encoding three functional groups ranged between that of PTCs and PDTCs/ATCs.

Effect of Metabolic Health and Obesity Phenotype on the Risk of Pancreatic Cancer: A Nationwide Population-Based Cohort Study.

BACKGROUND: Recently, a few studies have reported different results regarding the relationship between metabolic health and obesity phenotype and several cancers. We examined the effects of metabolic health and obesity phenotype on pancreatic cancer using a nationwide population-based cohort database. METHODS: Using the Korean National Health Insurance Service-Health Screening Cohort, we enrolled 347,434 Korean adults who underwent a health examination between 2009 and 2010 and were followed until 2015. This population was divided into four groups based on metabolically healthy status and body mass index (BMI): metabolically healthy normal weight (MHNW), metabolically unhealthy normal weight (MUNW), metabolically healthy obese (MHO), and metabolically unhealthy obese (MUO). RESULTS: Over a median follow-up of 6.1 (5.5-6.5) years, 886 individuals were diagnosed with pancreatic cancer. The adjusted HRs for incident pancreatic cancer were 1.52 [95% confidence interval (CI) 1.27-1.81] and 1.34 (95% CI, 1.12-1.61) for the MUNW and MUO phenotypes (compared with the MHNW phenotype) after adjusting for various confounding factors. However, compared with the MHNW phenotype, the MHO phenotype did not show an elevated risk of pancreatic cancer. Moreover, the HR for pancreatic cancer gradually increased with an increase in number of metabolically unhealthy components, even after adjusting for BMI (P trend < 0.001). CONCLUSIONS: Regardless of BMI, metabolically unhealthy phenotype demonstrated significantly increased risk of pancreatic cancer, whereas obese individuals with metabolically healthy phenotype did not. IMPACT: These findings suggest that metabolically unhealthy phenotype might represent a potential risk factor for pancreatic cancer occurrence independent of obesity.

Immune Profiling of Advanced Thyroid Cancers Using Fluorescent Multiplex Immunohistochemistry.

Background: Advanced thyroid cancers, including differentiated thyroid carcinoma (DTC) with distant metastasis, and anaplastic thyroid carcinoma (ATC), are associated with poor clinical outcomes and limited treatment options. This study aimed to determine the immune profiles of advanced thyroid cancers using fluorescent multiplex immunohistochemistry (F-MIHC) and multispectral imaging (MSI). Methods: Twenty-eight tissue samples were collected from 12 patients who had DTC with distant metastasis and from 16 with ATC. The samples were assessed using F-MIHC and MSI with antibodies against the cell surface molecules, cluster of differentiation (CD)4, CD8, programmed cell death-1 (PD-1), PD ligand 1 (PD-L1), forkhead box protein 3, and cytokeratin (CK). The expression of PD-L1 was evaluated using tumor proportion score (TPS) and combined positive score (CPS). Results: Significantly, more PD-L1-positive tumor cells (CK+PD-L1+) per mm2 were found in ATC samples than in DTC samples (183.5 vs. 0.03, p < 0.001). Lymphocyte infiltration was significantly increased in ATC compared with DTC, with significantly more PD-L1- or PD-1-positive lymphocytes in ATC samples than in DTC samples. The TPS and CPS for PD-L1 expression were negative in all DTC samples but positive in 81% and 94% of ATC samples, respectively. Conclusions: Immune profiling revealed significant differences between advanced DTC and ATC, particularly in terms of PD-L1 expression and lymphocyte infiltration. Therefore, immune profiling using F-MIHC and MSI can provide invaluable information regarding tumor microenvironments, which could help select candidates for immunotherapy.

Clinical Outcomes after Early and Delayed Radioiodine Remnant Ablation in Patients with Low-Risk Papillary Thyroid Carcinoma: Propensity Score Matching Analysis.

BACKGROUND: The clinical outcomes of delayed radioiodine remnant ablation (RRA) therapy in patients with low-risk papillary thyroid carcinoma (PTC) are unclear. We aimed to evaluate the clinical impact of the interval between total thyroidectomy (TT) and RRA therapy in patients with low-risk PTC. METHODS: We included 526 patients who underwent TT and RRA for low-risk PTC with a primary tumor size of >1 cm between 2000 and 2012. Patients were divided into the early (<90 days) and the delayed (≥90 days) RRA groups based on the interval between TT and RRA. The results of diagnostic whole-body scan (DxWBS), ongoing risk stratification (ORS; response to therapy), and disease-free survival (DFS) were evaluated before and after propensity score matching (PSM). RESULTS: Among the 526 patients, 75 (14.3%) patients underwent delayed RRA; they had more cervical lymph node metastasis and received a higher RRA dose than those who underwent early RRA. The median follow-up period was 9.1 years after initial therapy, and the structural recurrence rate was 1.9%. In DxWBS, 60 patients had focal iodine uptake limited in operative bed, with no significant difference between groups. According to ORS, 78%, 20%, 1%, and 1% patients were classified into excellent, indeterminate, biochemical incomplete, and structural incomplete response groups, respectively. There was no significant difference in ORS or DFS between groups before and after PSM. CONCLUSION: The timing of the first RRA had no clinical impact in patients with low-risk PTC. Thus, the clinical decision for RRA can be determined >3 months after TT considering other prognostic factors.

Quality of Life in Patients with Papillary Thyroid Microcarcinoma According to Treatment: Total Thyroidectomy with or without Radioactive Iodine Ablation.

BACKGROUND: Recently, there has been some controversy regarding the role of radioactive iodine (RAI) ablation in the treatment of low-risk differentiated thyroid carcinoma (DTC), especially papillary thyroid microcarcinoma (PTMC). This study aimed to compare quality of life (QoL) parameters between patients with PTMC who underwent total thyroidectomy (TT) alone and those who underwent TT with RAI ablation. METHODS: In this cross-sectional study, patients with PTMC who underwent TT with/without RAI remnant ablation were prospectively enrolled between June 2016 and October 2017. All patients completed three questionnaires: the 12-item short-form health survey (SF-12), thyroid cancer-specific quality of life (THYCA-QoL) questionnaire, and fear of progression (FoP) questionnaire. RESULTS: The TT and TT with RAI groups comprised 107 and 182 patients, respectively. The TT with RAI group had significantly lower serum thyrotropin (TSH) levels than the TT group. However, after matching for TSH levels between the groups (n=100 in both groups), there were no significant differences in baseline characteristics. According to the SF-12, the score for general health was significantly lower in the TT with RAI group than in the TT group (P=0.047). The THYCA-QoL also showed a significant difference in the "felt chilly" score between groups (P=0.023). No significant differences in FoP scores were observed between the groups. CONCLUSION: Patients with PTMC who underwent TT with RAI ablation experienced more health-related problems than those managed with TT alone. These findings support the idea that RAI ablation should be carefully considered in patients with low-risk DTCs.

Genetic profile of advanced thyroid cancers in relation to distant metastasis.

Major clinical challenges exist with differentiated thyroid cancers with distant metastases or rare but aggressive types, such as poorly differentiated thyroid carcinomas and anaplastic thyroid carcinomas. The precise characterization of the mutational profile in these advanced thyroid cancers is crucial. Samples were collected from primary tumors and distant metastases of 64 patients with distant metastases from differentiated thyroid cancer, poorly differentiated thyroid carcinoma, or anaplastic thyroid carcinoma. Targeted next-generation sequencing was performed with 50 known thyroid-cancer-related genes. Of the 82 tissues, 63 were from primary tumors and 19 from distant metastases. The most prevalent mutation observed from the primary tumors was TERT promoter mutation (56%), followed by BRAF (41%) and RAS (24%) mutations. TP3 was altered by 11%. Mutations in histone methyltransferases, SWI/SNF subunit-related genes, and PI3K/AKT/mTOR pathway-related genes were present in 42%, 12%, and 22%, respectively. When the mutational status was analyzed in 15 matched pairs of thyroid tumors and their matched distant metastases and one pair of distant metastases with two distinct sites, the concordance was high. A similar frequency of mutations in TERT promoter (58%) and BRAF (42%) as well as histone methyltransferases (37%), SWI/SNF subunits (10%), and PI3K/AKT/mTOR pathway (26%) were noted. The same main, early and late mutations were practically always present in individual primary tumor-metastasis pairs. Enrichment of TERT promoter, BRAF, and RAS mutations were detected in highly advanced thyroid cancers with distant metastasis. The genetic profiles of primary thyroid tumors and their corresponding distant metastases showed a high concordance.

Lenvatinib for Radioactive Iodine-Refractory Differentiated Thyroid Carcinoma and Candidate Biomarkers Associated with Survival: A Multicenter Study in Korea.

Background: Lenvatinib, an oral multikinase inhibitor, is the latest addition to the treatment options for radioactive iodine (RAI)-refractory progressive differentiated thyroid carcinoma (DTC). This study investigated the efficacy of lenvatinib in real-world practice and prognostic biomarkers of survival. Methods: This multicenter study included 43 patients receiving lenvatinib as first-line or second-line treatment after sorafenib for RAI-refractory DTC. Progression-free survival (PFS) was evaluated according to various clinical factors including thyroglobulin doubling time (TgDT), tumor volume DT (TVDT), and tumor growth slope (TGS; slope of tumor change rate). Results: Patients were treated with lenvatinib for a median of 14 months; 32 were previously treated with sorafenib. The median follow-up from lenvatinib initiation to the last censoring or death was 16 months. The median starting dose of 20 mg was reduced to a median sustainable dose of 10 mg in accordance with patient adverse events (AEs). The median PFS was 21.8 months; the median overall survival was not reached. The disease control rate was 97.7%, with the first objective response at 3.8 months. PFS was not significantly associated with previous sorafenib treatment, metastatic sites, or sustainable dose. TGS measured before (TGSpre, p = 0.003) and after (TGSpost, p = 0.036) the initiation of lenvatinib was associated with PFS. The sum of the largest diameters of target lesions (p = 0.043) and TgDT (p = 0.024) were associated with PFS, but TVDT calculated before (TVDTpre, p = 0.923) or after (TVDTpost, p = 0.966) lenvatinib treatment did not impact PFS. Lenvatinib was withdrawn in 24 patients (55.8%): in 6 patients because of treatment-induced AEs and in 18 patients because of disease progression or poor performance status. AEs of any grade were reported in all patients, and grade 3-4 AEs in 23.2% of the patients. The most frequent AE was fatigue or asthenia. Conclusions: Our results indicate that reduced doses of lenvatinib triggered by emergent AEs did not abrogate its apparent efficacy in patients with RAI-refractory DTCs. Rather, the sustained use of reduced doses of lenvatinib with a low rate of severe AEs may have contributed to the favorable outcomes. TgDT and TGS can assist in predicting the outcomes in these patients.

Estimating the Growth Rate of Lung Metastases in Differentiated Thyroid Carcinoma: Response Evaluation Criteria in Solid Tumors or Doubling Time?

Background: Estimating the growth rate of lung metastases for the treatment of patients with metastases of differentiated thyroid carcinoma (DTC) is important. This study aimed to evaluate survival outcomes according to different criteria for estimating the growth rate of lung metastases. Methods: Patients with macronodular (≥1 cm) lung metastases of DTC who underwent total thyroidectomy and high-dose radioactive iodine therapy between 1995 and 2013 were enrolled. The time to progressive disease (PD) by the Response Evaluation Criteria in Solid Tumors (RECIST), average tumor volume doubling time of the two dominant target lung lesions (midDT), and thyroglobulin doubling time (TgDT) were measured in each patient, and their association with disease-specific survival (DSS) was evaluated. Results: Forty-four patients with target lung metastatic nodules with an initial maximal diameter of 1.3 cm (median) were followed-up for a median of 6.8 years after the diagnosis of lung metastases. Based on RECIST, 12 patients (27.3%) showed fast tumor progression, with time to PD <1 year. When assessed by midDT, nine patients (20.5%) had midDT ≤1 year, showing rapid tumor progression. Seven of 33 patients (21.2%) who were negative for thyroglobulin antibody had midDT <1 year. Growth rates assessed by all three criteria were significantly associated with DSS. However, midDT had the highest predictive value for DSS, with a proportion of variation explained of 33.6%. Five-year DSS was 29.6% in patients with midDT ≤1 year, 50.0% in patients with time to PD <1 year, and 42.9% in patients with TgDT <1 year. Conclusions: Among the different criteria for estimating the growth rate of metastases in patients with lung metastases of DTC, midDT was the most powerful for predicting DSS, in comparison with RECIST and TgDT. Performing at least three serial chest computed tomography scans during the first year from the diagnosis of lung metastases can facilitate early detection of patients with rapid tumor progression and provide objective guidance for initiation of systemic therapy.

Long-term clinical outcomes of papillary thyroid carcinoma patients with biochemical incomplete response.

PURPOSE: The aim of this study was to evaluate the long-term clinical outcomes of papillary thyroid carcinoma (PTC) patients exhibiting biochemical incomplete response (BIR) to initial therapy. METHODS: We evaluated 102 patients with PTC showing a BIR during the first 12-24 months after total thyroidectomy and radioactive iodine therapy. Patients were divided into three groups according to changes in stimulated thyroglobulin (Tg) and anti-Tg antibody (TgAb) levels: the increasing TgAb group (n = 19, 18.6%), the decreasing Tg group (n = 58, 56.9%), and the increasing Tg group (n = 25, 24.5%). RESULTS: With a median follow-up of 12 years, 43 (42%) patients had structural persistent disease as follows: 36 (84%) at regional sites and 7 (16%) at distant sites. The rate of structural persistent disease was significantly different between groups, with 21%, 41%, and 60% in the increasing TgAb, decreasing Tg, and increasing Tg groups, respectively (P = 0.012). Among patients without structural persistent disease, only 19 (18.6%) showed no evidence of disease and 40 (39.2%) were of a biochemical persistent status at the time of final follow-up. Increasing Tg after initial therapy was a significant risk factor for structural persistent disease in patients with BIR (HR, 4.16; 95% confidence interval (CI): 1.38-12.54, P = 0.011). CONCLUSIONS: PTC patients with BIR showed a high rate of structural persistent disease and Tg change after initial therapy is the most important prognostic factor for determining clinical outcomes of these patients.

Prognostic role of the lymphocyte-to-monocyte ratio for clinical outcomes of patients with progressive radioiodine-refractory differentiated thyroid carcinoma treated by sorafenib.

OBJECTIVES: The lymphocyte-to-monocyte ratio (LMR) reflects the status of tumour-infiltrating immune cells and host immunity. The LMR has been reported as a prognostic marker in various cancers. The present study evaluated the role of the LMR as a prognostic marker in patients with progressive radioiodine-refractory (RAIR) differentiated thyroid carcinoma (DTC). DESIGN: Retrospective cohort study. PATIENTS: Forty patients with progressive RAIR DTC who were treated by sorafenib with available baseline complete blood cell count data. MEASUREMENTS: We assessed the response rate, progression-free survival (PFS) and overall survival (OS). RESULTS: The patients were divided into low and high LMR groups based on their baseline LMRs (<4, n = 22, 55% and ≥4, n = 18, 45%, respectively). There were no significant differences in baseline characteristics between the groups. The OS curves differed significantly based on the LMR. The median OS of the low LMR group was 24.3 months and that of the high LMR group was not reached until the end of observation period (P = .015). The PFS curves and median PFS also differed significantly based on the LMR values (P = .019). In multivariate analysis, low LMR was an independent risk factor for all-cause mortality in patients with progressive RAIR DTC (hazard ratio, 2.64; 95% confidence interval: 1.04-6.72, P = .041). CONCLUSION: A low LMR was associated with poor response rate, PFS and OS in patients with progressive RAIR DTC treated with sorafenib. Thus, LMR could be a simple prognostic biomarker in patients with progressive RAIR DTC.

Modified risk stratification based on cervical lymph node metastases following lobectomy for papillary thyroid carcinoma.

OBJECTIVE: Evidence for American Thyroid Association (ATA) risk stratification stems largely from studies involving patients undergoing total thyroidectomy. We aimed to assess the risk of recurrence according to the present ATA risk stratification system in patients who underwent lobectomy. DESIGN: Retrospective cohort study. PATIENTS: Patients who underwent thyroid lobectomy for 1-4 cm-sized papillary thyroid carcinoma (n = 571). MEASUREMENTS: Disease-free survival (DFS) was compared according to the ATA risk stratification, and specific lymph node (LN) characteristics were evaluated to modify the ATA criteria with a higher predictability for recurrence. RESULTS: Based on the ATA risk stratification, 439 patients (61.1%) were classified into intermediate- or high-risk group, and consideration for completion thyroidectomy is suggested by ATA guidelines for these patients. However, no significant differences were found in DFS among the low-, intermediate- and high-risk groups (P = .9). In contrast, when patients were stratified according solely to the LN criteria from the ATA risk stratification, only 127 patients (22.2%) had intermediate risk (intermediate-N1a) and exhibited significantly poorer DFS than those with N0 disease (P = .035). Modifying the intermediate-N1a criteria by adding the extranodal extension (ENE) status and omitting the clinical nodal disease enabled the subclassification of 19 patients (3%) with a high risk for recurrence. CONCLUSIONS: The present study suggests that risk stratification based solely on LN metastases is more reasonable for predicting structural persistence/recurrence following lobectomy than that based on the overall ATA criteria. Considering the ENE status can assist in selecting patients with a high risk of recurrence to minimize further treatments.

Clinical Significance of Gross Invasion of Strap Muscles in Patients With 1- to 4-cm-Sized Papillary Thyroid Carcinoma Undergoing Lobectomy.

BACKGROUND: Given the emerging evidence supporting the lack of prognostic significance of gross extrathyroidal extension invading only strap muscles (strap-gETE), this study investigated whether lobectomy is feasible for patients with strap-gETE. METHODS: A retrospective cohort study was conducted with 636 patients who had 1- to 4-cm-sized papillary thyroid carcinoma (PTC) treated with thyroid lobectomy. Patients with gross invasion of perithyroidal organs other than strap muscles or synchronous distant metastasis were excluded from the study. Disease-free survival (DFS) was compared according to the presence of strap-gETE. RESULTS: Strap-gETE was present in 50 patients (7.9%), with the remaining 586 patients (92.1%) showing no evidence of gETE. During the median follow-up period of 7.4 years, 6% of the patients with strap-gETE and 5.1% of the patients without gETE experienced structural persistent/recurrent disease (p = 0.99). No differences in DFS were observed between the two groups (hazard ratio [HR], 1.24; 95% confidence interval [CI], 0.38-4.08; p = 0.720). After adjustment for five major risk factors (age, gender, tumor size, multifocality, and cervical lymph node metastasis status) in the multivariate analysis, the presence of strap-gETE did not exhibit an independent role in the development of structural persistent/recurrent disease (HR 1.05; 95% CI 0.24-4.53, p = 0.950). CONCLUSIONS: Strap-gETE did not increase the risk of structural persistent/recurrent disease for the patients who underwent lobectomy for 1- to 4-cm-sized PTC. The study data support the limited role of strap-gETE in clinical outcomes and may broaden the indications for lobectomy for patients with PTCs.

Tumor Volume Doubling Time in Active Surveillance of Papillary Thyroid Carcinoma.

Background: Tumor volume (TV) of papillary thyroid carcinoma (PTC) increases exponentially during active surveillance, and the growth rate differs for each patient. TV doubling time (TVDT) is considered a strong dynamic marker for the prediction of the growth rate and progression of the tumor. Methods: This cohort study analyzed 273 PTC patients who underwent active surveillance for more than one year rather than immediate thyroid surgery. TVDT was calculated in each patient, and patients were divided into two groups: rapid-growing (TVDT <5 years) and stable (TVDT ≥5 years). Clinical and initial ultrasonography (US) features between the two groups were compared. Results: The median patient age was 51.1 years (interquartile range [IQR] 42.2-61.0 years), and 76% of the patients were women. The initial TV of PTC was 62.1 mm3 (IQR 28.1-122.8 mm3). During a median of 42 months (IQR 29-61 months) of active surveillance, 10.3% of the patients had a TVDT of less than two years, 5.1% had a TVDT between two and three years, 6.2% had a TVDT between three and four years, 6.6% had a TVDT between four and five years, and 71.8% had a TVDT of five years or more. Patients in the rapid-growing group (77 patients; 28.2%) were significantly younger (p = 0.004) than those in the stable group (196 patients; 71.8%). Being younger than 50 years of age was significantly associated with rapid tumor growth of PTC (odds ratio = 2.31 [confidence interval 1.30-4.31], p = 0.004) in multivariate analysis. In ultrasound findings, macrocalcification was independently associated with rapid tumor growing of PTCs (odds ratio = 4.98 [confidence interval 2.19-11.69], p < 0.001). Conclusions: TVDT is a good indicator for presenting the growing velocity of PTCs during active surveillance. Younger age and macrocalcification in the initial US were associated with rapid-growing PTCs. Determination of TVDT during the early phase of active surveillance may be helpful for the prediction of rapidly progressing PTCs and deciding whether to adopt an early surgical approach.