Undercover active surveillance of small highly suspicious thyroid nodules without fine needle aspiration.

PURPOSE: Active surveillance (AS) is an alternative treatment approach for small, low-risk papillary thyroid microcarcinoma (PTMC). This study aimed to assess the clinical outcomes of small, highly suspicious nodules lacking initial cytological confirmation. METHODS: This study included 112 patients with highly suspicious nodules measuring ≤ 10 mm who underwent serial ultrasound at Asan Medical Center, Korea, between 2010 and 2023. RESULTS: The median participant age was 51.9 years, and 74.1% were female. The median maximal tumor diameter and tumor volume (TV) were 4.5 (interquartile range [IQR] 3.7-5.2, range 2.2-9.3) mm and 25.2 (IQR 13.1-49.2) mm3, respectively. During a median follow-up period of 4.8 years, four (3.6%) patients showed a ≥ 3 mm increase in maximal diameter, and two (1.8%) developed new lymph node (LN) metastasis. Disease progression was associated with a TV doubling time (TVDT) of < 5 years and a ≥ 75% increase in TV (p = 0.017 and p < 0.005, respectively). Furthermore, 34.8% of patients underwent fine needle aspiration (FNA), primarily at their own request, yielding 46.2%, 5.1%, 41.0%, and 12.8 % malignant, benign, indeterminate, and non-diagnostic results, respectively. Of 18 patients with PTMC, 8 (44.4%) underwent surgery and 10 continued AS, with no LN metastasis during AS and no postoperative recurrence. CONCLUSION: Small, highly suspicious nodules had a low disease progression rate during AS without FNA. Disease progression was associated with a TVDT of < 5 years and a ≥ 75% increase in TV. FNA can be performed more conservatively than it currently is in patients with highly suspicious nodules measuring ≤ 10 mm.

Changes in peripheral blood immune cell population in thyroid cancer patients treated with lenvatinib.

This study evaluated changes in the peripheral blood immune cell population in patients with advanced thyroid cancer receiving lenvatinib treatment to confirm the immune-modulatory effect of lenvatinib. After obtaining informed consent from patients, we prospectively collected 20 ml of whole blood at 2-3 months intervals 2-4 times from each patient; peripheral blood mononuclear cells (PBMCs) were separated, and the Maxpar Direct Immune Profiling Assay was performed. A total of 10 patients were enrolled, and 31 blood samples were obtained. The median age of patients was 65 years, and all patients showed durable responses to the lenvatinib treatment. When we compared the PBMC profiles between the pre-treatment, on-treatment, and off-treatment samples, the peripheral natural killer (NK) cell proportion differed significantly. The proportion of NK cells among total live cells significantly increased from 9.3 ± 4.5 (%) in the pre-treatment samples to 20.8 ± 7.9 (%) in the on-treatment samples (P = 0.009) and decreased to 13.3 ± 3.1 (%) in the off-treatment samples (P = 0.07). There was a significant increase in the peripheral NK cell population with lenvatinib treatment in advanced thyroid cancer patients. This finding confirms the immune-modulatory effect of lenvatinib.

Serum thyroglobulin testing after thyroid lobectomy in patients with 1-4 cm papillary thyroid carcinoma.

BACKGROUND: The role of measuring serum thyroglobulin (Tg) levels in patients who have undergone lobectomy has not been proven. The goal of this research is to see if serum Tg levels can predict the recurrence of papillary thyroid carcinoma (PTC) after lobectomy. METHODS: The 463 patients with 1-4 cm PTC who underwent lobectomy between January 2005 and December 2012, were included in this retrospective cohort study. Postoperative serum Tg levels and neck ultrasound were evaluated every 6-12 months after lobectomy during a median 7.8-year follow-up period. The receiver operating characteristic (ROC) curve and its area under the ROC curve (AUC) was used to assess the diagnostic performance of serum Tg levels. RESULTS: During the follow-up, the structural recurrent disease was confirmed in 30 patients (6.5%). The serum Tg levels measured by initial Tg, maximal Tg, and last Tg did not differ statistically between the recurrence and non-recurrence groups. According to our findings, serial patterns of serum maximal Tg variations in 30 patients with recurrence showed no obvious trend and no rising trend toward recurrence before detecting recurrence. The AUC was 54.5% (IQR 43.1%-65.9%) in the ROC curve analysis, indicating that it was not significantly different from the random classifier. CONCLUSION: Serum Tg levels did not differ significantly between the recurrence and non-recurrence groups, and there was no tendency for the recurrence group to increase Tg levels. In patients with PTC who underwent lobectomy, monitoring Tg levels regularly provides little benefit in predicting recurrence.

Inflammatory biomarkers predict outcomes of patients with radioactive iodine refractory thyroid cancer treated with sorafenib.

BACKGROUND: The objective of this multicenter, retrospective cohort study was to evaluate the ability of inflammatory biomarkers representing the host immune system to predict outcomes in 70 patients with progressive radioactive iodine (RAI)-refractory thyroid cancer who were treated with sorafenib. METHOD: Patients were divided into low and high inflammatory biomarker groups based on median values. Progression-free survival (PFS) and overall survival (OS) were assessed based on the lymphocyte-to-monocyte ratio (LMR), neutrophil-to-lymphocyte ratio (NLR), and platelet-to-lymphocyte ratio (PLR). RESULTS: The median LMR, NLR, and PLR values were 3.4, 2.2, and 140.1, respectively. No significant differences were observed in baseline characteristics of high and low LMR, NLR and PLR groups. Median PFS values were 6.6 and 19.5 months in the low and high LMR groups, respectively (P < 0.001). Compared with the high NLR and PLR groups, PFS was significantly prolonged in the low NLR and PLR groups (P = 0.003 and P = 0.041 respectively). In the multivariate analysis, low LMR and high NLR were associated with poor PFS after adjusting for multiple confounding factors including age, sex, pathology, disease-related symptoms, serum thyroglobulin level, lung-only metastasis, cumulative RAI dose, time from diagnosis, and longer diameter of the target lesion (hazard ratio, HR = 2.42; 95% confidence interval, CI 1.25-4.71; P = 0.009, and HR = 2.09; CI, 1.06-4.14; P = 0.033, respectively). High LMR, low NLR, and low PLR were significantly associated with prolonged OS (P = 0.011, P = 0.023, and P = 0.007, respectively). Patients with at least one risk factors for inflammatory biomarkers presented a significantly lower PFS (HR 2.29; CI, 1.36-3.84; P = 0.003) and OS (HR 2.95; CI, 1.49-5.81; P = 0.006) than patients without any risk factor. CONCLUSION: Baseline inflammatory biomarkers successfully predicted PFS and OS in patients with progressive RAI-refractory thyroid cancer treated with sorafenib. These prognostic biomarkers might help arrive at appropriate clinical decisions regarding the use of sorafenib.

Long-term follow-up result of antithyroid drug treatment of Graves' hyperthyroidism in a large cohort.

Objective: This study evaluated the efficacy of antithyroid drugs (ATDs) and risk factors associated with the recurrence of Graves' hyperthyroidism using a comprehensive retrospective cohort. Methods: We included 1829 patients newly diagnosed with Graves' hyperthyroidism, with sufficient follow-up data. Clinical outcomes of the patients and risk factors associated with recurrence-free survival, including the changes in thyrotropin receptor antibody, were evaluated. Results: The median age of the patients was 44.5 years, and 69% were female. Among the patients, 1235 had a chance to withdraw ATD after a median of 23 (interquartile range (IQR) 17.0-35.5) months of treatment. The first remission rate was 55.6% during a median of 72.7 months of follow-up. After the first recurrence, 95% of patients underwent the second course of ATD treatment for a median of 21.1 (IQR 14.8-31.7) months, and the remission rate was 54.1%. During a median of 67 months of follow-up, 7.7% of patients underwent surgery, and 10.5% underwent radioactive iodine therapy. Approximately 30% were still on ATD therapy for recurrent disease or prolonged low-dose maintenance. Younger age (<45 years), male sex, and fluctuating or smoldering of TRAb levels were independent risk factors of the first recurrence after ATD treatment. Conclusions: ATD treatment is an acceptable option for the initial treatment of Graves' hyperthyroidism as well as for recurrent disease. The optimal treatment period for ATD treatment needs to be determined using the individual risk factors of recurrence.

2021 Asia-Pacific Graves' Disease Consortium Survey of Clinical Practice Patterns in the Management of Graves' Disease.

AIM: Although Graves' disease (GD) is common in endocrine practices worldwide, global differences in diagnosis and management remain. We sought to assess the current practices for GD in countries across Asia and the Pacific (APAC), and to compare these with previously published surveys from North America and Europe. METHODS: A web-based survey on GD management was conducted on practicing clinicians. Responses from 542 clinicians were received and subsequently analysed and compared to outcomes from similar surveys from other regions. RESULTS: A total of 542 respondents participated in the survey, 515 (95%) of whom completed all sections. Of these, 86% were medical specialists, 11% surgeons, and 3% nuclear medicine physicians. In addition to serum thyroid-stimulating hormone (TSH) and free thyroxine assays, most respondents would request TSH-receptor autoantibody (TRAb) measurement (68%) during initial work-up. Thyroid ultrasound is requested by about half of respondents (53%), while the use of nuclear medicine scans is limited. The preferred first-line treatment is anti-thyroid drug (ATD) therapy (79%) with methimazole (MMI) or carbimazole (CBZ), followed by radioiodine (RAI; 19%) and surgery (2%). In case of surgery, one-third of respondents would opt for a subtotal rather than a total thyroidectomy. In case of mild Graves orbitopathy (GO), ATDs (67%) remains the preferred treatment, but a larger proportion of clinicians prefer surgery (20%). For a patient with intention to conceive, the preferred treatment pattern remained unchanged, although propylthiouracil (PTU) became the preferred ATD-agent during the first trimester. In comparison to European and American practices, marked differences were noted in the relatively infrequent usage of nuclear medicine scans and the overall higher use of a ATDs and ß-blockers and adjunctive ATD-treatment during RAI in the APAC-group. CONCLUSION: Although regional differences regarding the diagnosis and management of GD are apparent in this first pan-Asia-Pacific survey, this study reveals the overall approach to the management of this disease in Asia-Pacific generally tends to fall between the trends appreciated in the American and European cohorts.

Lenvatinib Compared with Sorafenib as a First-Line Treatment for Radioactive Iodine-Refractory, Progressive, Differentiated Thyroid Carcinoma: Real-World Outcomes in a Multicenter Retrospective Cohort Study.

Background: Sorafenib and lenvatinib have been widely adopted to treat radioactive iodine (RAI)-refractory differentiated thyroid carcinoma (DTC). However, limited data exist regarding a direct comparison of these tyrosine kinase inhibitors (TKIs). We aimed to evaluate the clinical efficacy and safety of two TKIs as first-line therapy in patients with distant metastatic or locally advanced, progressive, RAI-refractory DTC in real-world practice. Methods: In this multicenter, retrospective cohort study, we evaluated 136 patients with progressive distant metastatic or locally advanced, progressive, RAI-refractory DTC or poorly differentiated thyroid carcinoma (PDTC) who received first-line sorafenib or lenvatinib treatment. The primary outcome was progression-free survival (PFS). We also evaluated the objective response rate, disease-control rate, clinical benefit rate, and safety. Results: The median age of the patients was 68 years, and 35% (47/136) were male. Eighty and fifty-six patients were included in the sorafenib and lenvatinib groups, respectively. The median PFS was 13.3 months [95% confidence interval, CI, 9.9-18.1 months] in the sorafenib group and 35.3 months [CI, 18.2 months to upper limit not reported as the median was not reached] in the lenvatinib group (p = 0.001). A significantly prolonged PFS was observed in the lenvatinib group (compared with the sorafenib group) after adjusting for age, sex, pathology, disease-related symptom, lung-only metastasis, cumulative RAI dose, time from diagnosis, treatment duration, and longest diameter of the target lesion (hazard ratio = 0.34, CI, 0.19-0.60, p < 0.001). The partial response rate was 24% and 59% in the sorafenib and lenvatinib groups, respectively (p < 0.001). More common grade 3-4 adverse events were hypertension (16%, 9/56 vs. 1%, 1/80, p = 0.002) and proteinuria (32%, 18/56 vs. 0%, p < 0.001) in the lenvatinib group, and hand-foot skin reaction (24%, 19/80 vs. 4%, 2/56, p = 0.001) in the sorafenib group. Conclusion: In our study of Asian patients, first-line lenvatinib treatment of metastatic or locally advanced, progressive, RAI-refractory DTC or PDTC was associated with a longer PFS compared with sorafenib. However, severe hypertension and proteinuria were observed more frequently after lenvatinib treatment than after sorafenib treatment.

Limitations of fine-needle aspiration and core needle biopsies in the diagnosis of tall cell variant of papillary thyroid carcinoma.

BACKGROUND: The tall cell variant papillary thyroid carcinoma (TCV-PTC) shows aggressive behaviour. Thus far, the diagnosis of TCV-PTC can only be confirmed using the postoperative specimen. This study aims to evaluate whether fine-needle aspiration (FNA) or core needle biopsy (CNB) could diagnose TCV-PTC preoperatively. METHODS: This is a retrospective cohort study. We included adult patients diagnosed with TCV-PTC or PTC with tall cell features (TCF) at final surgical pathology between January 2015 and December 2018. Preoperative histology was reviewed for six cytomorphologic features suggesting TCV-PTC in FNA or the percentage of tall cells in the CNB specimen. The postoperative pathology was also reviewed to confirm the percentage of tall cells. RESULTS: A total of 119 patients were included in this study; 35 (29%) patients with PTC with TCF served as controls. The most frequent cytomorphological feature in FNA samples of TCV-PTC was tall columnar cells, including single tombstone-like cells (70%). Among 43 TCV-PTC evaluated by FNA, 3 FNA (7%) revealed the absence of any of the six cytomorphologic features suggesting TCV-PTC. When we defined 30% of tall cells in CNB specimens as a cutoff suggesting TCV-PTC, only 16 (41%) TCV-PTCs could be preoperatively detected, and 3 (7%) TCV-PTCs did not have any tall cells. The proportion of tall cells was not associated with the postoperative percentage of tall cells. CONCLUSION: Both cytomorphologic features in FNA and the percentage of tall cells in CNB present limitations for use as accurate preoperative diagnostic tools of TCV-PTC.

Prognosis of Patients with 1-4 cm Papillary Thyroid Cancer Who Underwent Lobectomy: Focus on Gross Extrathyroidal Extension Invading Only the Strap Muscles.

BACKGROUND: This study was designed to evaluate the prognostic implication of gross extrathyroidal extension (ETE) invading the strap muscles after thyroid lobectomy in patients with 1-4 cm papillary thyroid cancer (PTC). METHODS: This retrospective cohort study included patients with 1-4 cm PTC who underwent thyroid lobectomy from 2005 to 2012. Overall, 595 patients were enrolled after excluding patients with aggressive variants of PTC, gross ETE into a major neck structure, and lateral cervical lymph node (LN) metastasis. We evaluated the risk factors for structural recurrence after lobectomy in 1-4 cm PTC. RESULTS: Seventy-eight patients (13.1%) had gross ETE invading only the strap muscles. During the median follow-up period of 7.7 years, structural recurrence was confirmed in 35 patients (5.9%). The presence of gross ETE was an independent risk factor for structural recurrence (hazard ratio 2.54, 95% confidence interval 1.19-5.44; p = 0.016). Subgroup analysis of patients with gross ETE showed that 11 and 47 patients had low- and intermediate-risk LN metastasis, respectively. A significant difference in recurrence-free survival was observed according to the degree of cervical LN metastasis (p = 0.03). Those without LN metastasis or low-risk LNs had a 75% lower risk of recurrence when compared with those with both gross ETE and intermediate-risk LNs. CONCLUSION: Gross ETE and intermediate-risk cervical LN metastasis were associated with a significantly high risk of recurrence after lobectomy in patients with 1-4 cm PTC. Completion thyroidectomy would be considered in this subgroup of patients but not in all patients with gross ETE invading only the strap muscles.

Effects of dabrafenib and erlotinib combination treatment on anaplastic thyroid carcinoma.

Dabrafenib is a BRAF kinase inhibitor approved for treatment of BRAF-mutated anaplastic thyroid carcinoma (ATC) in combination with trametinib. Erlotinib is a tyrosine kinase inhibitor of EGF receptor (EGFR). We evaluated effects of dabrafenib and erlotinib combination treatment on ATC cells in vitro and in vivo. Cell proliferation, colony formation, apoptosis, and migration of ATC cells harboring a BRAF mutation (BHT101, 8505C, and SW1736) were evaluated after treatment with dabrafenib in combination with erlotinib or trametinib. The changes in activation of mitogen extracellular kinase (MEK) and extracellular signal-related kinase (ERK) signaling were also evaluated by Western blot analysis. Effects of these combinations were also evaluated using an in vivo xenograft model. First, we detected EGFR activation in dabrafenib-resistant SW1736 cells using a phospho-receptor tyrosine kinase array. A dabrafenib and erlotinib combination synergistically inhibited cell proliferation, colony formation, and migration, with an induction of apoptotic cell death in all three ATC cells, compared with dabrafenib or erlotinib alone. This synergistic effect was comparable with a dabrafenib and trametinib combination. The dabrafenib and erlotinib combination effectively inhibited phosphorylated (p)-MEK, p-ERK, and p-EGFR expressions compared with dabrafenib or erlotinib alone, while the dabrafenib and trametinib combination only inhibited p-MEK and p-ERK expressions. The dabrafenib with erlotinib or trametinib combinations also significantly suppressed tumor growth and induced apoptosis in a BHT101 xenograft model. The dabrafenib and erlotinib combination could be a potential novel treatment regimen to overcome drug resistance to dabrafenib alone in patients with BRAF-mutated ATC.

Graves' disease diagnosed in remnant thyroid after lobectomy for thyroid cancer.

BACKGROUND: The coexistence of Graves' disease with thyroid cancer is well-known and total thyroidectomy is recommended in such cases. However, Graves' disease might be dormant at the time of surgery and diagnosed after lobectomy for thyroid cancer. METHODS: We assessed the incidence and clinicopathological characteristic of newly developed Graves' disease after lobectomy for thyroid cancer between 2010 and 2019. RESULTS: In all, 11043 patients underwent lobectomy for thyroid cancer during the study period, and 26 (0.2%) were diagnosed with Graves' disease during follow-up. The median age was 43.8 years, 88.5% were female, and all were euthyroid before surgery. The median time from lobectomy to the diagnosis of Graves' disease was 3.3 years. Half of the patients were diagnosed based on thyroid function tests during routine follow-up, and others were diagnosed due to symptoms of thyrotoxicosis. Among patients who had checked preoperative thyroid autoantibodies, 61.1% showed positivity. Twenty-one (80.8%), and 2 (7.7%) patients received antithyroid drugs and radioactive iodine therapy, respectively, and 3 (11.5%) underwent completion thyroidectomy. CONCLUSION: Although rare, Graves' disease can occur in the remnant thyroid after lobectomy. Such patients are more likely to have autoantibodies. An appropriate workup is required when hyperthyroidism is found during the follow-up of patients after lobectomy.

Comparison of 99mTc Pertechnetate Thyroid Uptake Rates by Gamma Probe and Gamma Camera Methods for Differentiating Graves' Disease and Thyroiditis.

BACKGROUND: Technetium-99 m (99mTc) pertechnetate thyroid uptake rate can be measured with a gamma probe or gamma camera. This study was performed to compare their diagnostic accuracy for evaluating patients with thyrotoxicosis. METHODS: We retrospectively reviewed 99mTc pertechnetate thyroid uptake rate records of patients by both gamma probe and camera methods at a tertiary center in Korea from November 2019 to June 2020. We determined the normal reference ranges of thyroid uptake rate by two methods and compared both methods for differentiating Graves' disease and thyroiditis in patients with thyrotoxicosis by receiver operating characteristic curve analysis. RESULTS: A total of 371 patients (euthyroid 89, Graves 167, and thyroiditis 115) were included. The normal reference range for thyroid uptake rate in euthyroid patients was 0.3-1.9% and 2.0-4.7% for the camera and probe methods, respectively. For differentiating Graves' disease and thyroiditis, the area under the curve of the camera method (0.988) was significantly greater than that (0.975) of the probe method (p = 0.030). The sensitivity and specificity for the probe method were 92.2% and 91.3%, respectively, with a cut-off value of 3.0%. Those for the camera method were 93.4% and 94.8%, respectively, with a cut-off value of 0.7%. CONCLUSION: 99mTc pertechnetate thyroid uptake rate measured by the camera method had higher diagnostic accuracy than the probe method for evaluating patients with thyrotoxicosis. Considering the diagnostic accuracy and patient convenience, the thyroid uptake rate measured by the camera method would be a good substitute for the probe method.

Effect of TSH levels during active surveillance of PTMC according to age.

We previously reported that high thyroid-stimulating hormone (TSH) levels are associated with papillary thyroid microcarcinoma (PTMC) progression during active surveillance. However, validation with multicenter, long-term data, and identification of appropriate age or TSH levels are needed. This multicenter retrospective study enrolled PTMC patients under active surveillance with TSH measurements and ultrasonography. The primary outcome was PTMC progression (volume increase ≥50%, size increase ≥3 mm, or new lymph node (LN) metastasis). PTMC progression according to time-weighted average of TSH (TW-TSH) groups was compared using survival analyses in overall patients and each age subgroups (<40, 40-49, 50-59, and ≥60 years). The identification of TW-TSH cutoff point for PTMC progression and trend analysis of PTMC progression rate according to LT4 treatment were also performed. During 1061 person-years of follow-up, 93 of 234 patients (39.7%) showed PTMC progression (90, 17, and 5 patients for volume increase ≥50%, size increase ≥3 mm, and new LN metastasis, respectively). The highest TW-TSH group was the risk factor most strongly associated with PTMC progression (hazard ratio 2.13 (1.24-3.65); P = 0.006), but the impact was significant only in patients aged <40 or 40-49 years (hazard ratio 30.79 (2.90-326.49; P = 0.004), 2.55 (1.00-6.47; P = 0.049)). For patients aged <50 years, TW-TSH cutoff for PTMC progression was 1.74 mU/L, and PTMC progression rates successively increased in the order of effective, no, and ineffective LT4 treatment group (P for trend = 0.034). In young PTMC patients (<50 years), sustained low-normal TSH levels during active surveillance might be helpful to prevent progression.

Clinical Characteristics and Prognosis of Coexisting Thyroid Cancer in Patients with Graves' Disease: A Retrospective Multicenter Study.

BACKGROUND: The association between Graves' disease (GD) and co-existing thyroid cancer is still controversial and most of the previously reported data have been based on surgically treated GD patients. This study investigated the clinicopathological findings and prognosis of concomitant thyroid cancer in GD patients in the era of widespread application of ultrasonography. METHODS: Data of GD patients who underwent thyroidectomy for thyroid cancer between 2010 and 2019 in three tertiary hospitals in South Korea (Asan Medical Center, Chonnam National University Hwasun Hospital, and Pusan National University Hospital) were collected and analyzed retrospectively. In the subgroup analysis, aggressiveness and clinical outcomes of thyroid cancer were compared nodular GD and non-nodular GD groups according to the presence or absence of the thyroid nodules other than thyroid cancer (index nodules). RESULTS: Of the 15,159 GD patients treated at the hospitals during the study period, 262 (1.7%) underwent thyroidectomy for coexisting thyroid cancer. Eleven patients (4.2%) were diagnosed with occult thyroid cancer and 182 patients (69.5%) had microcarcinomas. No differences in thyroid cancer aggressiveness, ultrasonographic findings, or prognosis were observed between the nodular GD and non-nodular GD groups except the cancer subtype. In the multivariate analysis, only lymph node (LN) metastasis was an independent prognostic factor for recurrent/persistent disease of thyroid cancer arising in GD (P=0.020). CONCLUSION: The prevalence of concomitant thyroid cancer in GD patients was considerably lower than in previous reports. The clinical outcomes of thyroid cancer in GD patients were also excellent but, more cautious follow-up is necessary for patients with LN metastasis in the same way as for thyroid cancer in non-GD 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.

Clinicopathological Characteristics and Disease-Free Survival in Patients with Hürthle Cell Carcinoma: A Multicenter Cohort Study in South Korea.

BACKGROUND: Hürthle cell carcinoma (HCC), a type of thyroid carcinoma, is rare in South Korea, and few studies have investigated its prognosis. METHODS: This long-term multicenter retrospective cohort study evaluated the clinicopathological features and clinical outcomes in patients with HCC who underwent thyroid surgery between 1996 and 2009. RESULTS: The mean age of the 97 patients included in the study was 50.3 years, and 26.8% were male. The mean size of the primary tumor was 3.2±1.8 cm, and three (3.1%) patients had distant metastasis at initial diagnosis. Ultrasonographic findings were available for 73 patients; the number of nodules with low-, intermediate-, and high suspicion was 28 (38.4%), 27 (37.0%), and 18 (24.7%), respectively, based on the Korean-Thyroid Imaging Reporting and Data System. Preoperatively, follicular neoplasm (FN) or suspicion for FN accounted for 65.2% of the cases according to the Bethesda category, and 13% had malignancy or suspicious for malignancy. During a median follow-up of 8.5 years, eight (8.2%) patients had persistent/recurrent disease, and none died of HCC. Older age, gross extrathyroidal extension (ETE), and widely invasive types of tumors were significantly associated with distant metastasis (all P<0.01). Gross ETE (hazard ratio [HR], 27.7; 95% confidence interval [CI], 2.2 to 346.4; P=0.01) and widely invasive classification (HR, 6.5; 95% CI, 1.1 to 39.4; P=0.04) were independent risk factors for poor disease-free survival (DFS). CONCLUSION: The long-term prognosis of HCC is relatively favorable in South Korea from this study, although this is not a nation-wide data, and gross ETE and widely invasive cancer are significant prognostic factors for DFS. The diagnosis of HCC by ultrasonography and cytopathology remains challenging.

Active Surveillance as an Effective Management Option for Low-Risk Papillary Thyroid Microcarcinoma.

Active surveillance (AS) for low-risk papillary thyroid microcarcinoma (PTMC) has been accepted worldwide as safe and effective. Despite the growing acceptance of AS in the management of low-risk PTMCs, there are barriers to AS in real clinical settings, and it is important to understand and establish appropriate AS protocol from initial evaluation to follow-up. PTMC management strategies should be decided upon after careful consideration of patient and tumor characteristics by a multidisciplinary team of thyroid cancer specialists. Patients should understand the risks and benefits of AS, participate in decision-making and follow structured monitoring strategies. In this review, we discuss clinical outcomes of AS from previous studies, optimal indications and follow-up strategies for AS, and unresolved questions about AS.

Tumor Volume Doubling Time in Active Surveillance of Papillary Thyroid Microcarcinoma: A Multicenter Cohort Study in Korea.

Background: Some papillary thyroid microcarcinomas (PTMCs) may progress with tumor enlargement or development of new lymph node (LN) metastasis during active surveillance (AS). This study evaluated the relevant predictors of disease progression, especially new cervical LN metastasis. Methods: This was a long-term follow-up study conducted using a previous multicenter cohort of AS in Korea. After excluding 54 (14.2%) patients with a short follow-up duration, 326 PTMC patients were evaluated for tumor kinetics, including changes in tumor volume (TV) and TV doubling time (TVDT). Results: During a median follow-up duration of 4.9 years, 17 (5.2%, 95% confidence intervals [CI] 2.7-7.6%) patients showed a maximal diameter increase of ≥3 mm after a median of 4.0 years follow-up, while 9 (2.8%, CI 1.0-4.5%) developed new LN metastasis after a median of 2.2 years follow-up. New cervical LN metastasis occurred exclusively of a maximal diameter increase of ≥3 mm. The prevalence of new development of LN metastasis was higher in patients with TVDT <5 years (7.4%) than in those with TV ≥50% (3.2%). Furthermore, only TVDT <5 years was significantly associated with LN metastasis (p = 0.002). In univariate and multivariate analyses, TVDT <5 years was an independent risk factor for disease progression with respect to new development of LN metastasis (hazard ratio [HR] = 6.51, CI 1.73-24.50; p = 0.002) and tumor enlargement (HR = 20.89, CI 5.78-75.48; p < 0.001). Finally, 86 (22.6%) patients underwent delayed surgery, and the most common reason was patient anxiety. Conclusions: TVDT <5 years is a predictor of disease progression during AS in terms of new LN metastasis development as well as tumor enlargement. Determination of TVDT in the early phase of AS could help in predicting disease progression, tailoring follow-up intensity of AS and in determining if early surgical intervention is needed.