Ethanol ablation of papillary thyroid carcinoma nodal metastases: Long-term outcomes

BACKGROUND

Percutaneous ethanol ablation has emerged as a treatment for recurrent papillary thyroid carcinoma in the lateral neck after compartment-oriented therapeutic lymphadenectomy. However, the safety and utility of percutaneous ethanol ablation as a primary treatment modality for lateral neck metastases remains undefined. We aimed to investigate long-term outcomes of percutaneous ethanol ablation of lateral neck papillary thyroid carcinoma recurrence both with and without prior lymphadenectomy.

METHODS

We conducted a retrospective study of patients with lateral neck papillary thyroid carcinoma treated with percutaneous ethanol ablation from 2013 to 2018. Patient characteristics, disease volume, morbidity, and recurrence (development of new lymphadenopathy within a percutaneous ethanol ablation-treated nodal compartment) were assessed.

RESULTS

We identified 117 patients who underwent percutaneous ethanol ablation for papillary thyroid carcinoma lateral neck metastases-67 (57%) had a prior lateral neck dissection. Median follow-up after percutaneous ethanol ablation was 5.5 years (interquartile range 3.1-7.5). On average, 1.4 lymph nodes (range: 1-6) were treated. Three patients (3%) developed transient nerve-related complications after percutaneous ethanol ablation. Of 15 patients who underwent lateral neck dissection after percutaneous ethanol ablation (including patients undergoing repeat lateral neck dissection), dissection was "difficult" in 8 (53%) (7 of whom had previously undergone lateral neck dissection), and 4 (27%) developed complications (transient nerve dysfunction = 3, lymphatic leak = 1). Thirty-three patients (28%) developed recurrent papillary thyroid carcinoma. No difference in recurrence was seen between patients who did or did not undergo pre-percutaneous ethanol ablation lateral neck dissection (no pre-percutaneous ethanol ablation lateral neck dissection: 24%, pre-percutaneous ethanol ablation lateral neck dissection, 31%; hazard ratio = 1.27, 95% confidence interval 0.62-2.58; P = .514).

CONCLUSION

Percutaneous ethanol ablation may be a safe primary treatment modality for papillary thyroid carcinoma lateral neck nodal recurrence in selected patients with low-volume nodal disease.

Clinician feedback using a shared decision-making tool for the evaluation of patients with thyroid nodules-an observational study

BACKGROUND

We pilot-tested an encounter conversation aid to support shared decision making (SDM) between patients with thyroid nodules and their clinicians.

OBJECTIVE

Characterize the clinician feedback after providing care to patients with thyroid nodules using a tool to promote SDM conversations during the clinical encounter, and evaluate how clinicians used the tool during the visit.

METHODS

Mixed method study in two academic centers in the U.S., including adult patients presenting for evaluation of thyroid nodules and their clinicians. We thematically analyzed interviews with clinicians after they used the SDM tool in at least three visits to characterize their feedback. Additionally, investigators evaluated visits recordings to determine the extent to which clinicians engaged patients in the decision-making process (OPTION score, scale 0 to 100, higher levels indicating higher involvement), the tool's components used (fidelity), and encounter duration. Using a post-visit survey, we evaluated the extent to which clinicians felt the tool was easy to use, helpful, and supportive of the patient-clinician collaboration.

RESULTS

Thirteen clinicians participated in the study and used the SDM tool in the care of 53 patients. Clinicians thought the tool was well-organized and beneficial to patients and clinicians. Clinicians noticed a change in their routine with the use of the conversation aid and suggested it needed to be more flexible to better support varying conversations. The median OPTION score was 34, the fidelity of use 75%, and the median visit duration 17 min. In most encounters, clinicians agreed or strongly agreed the tool was easy to use (86%), helpful (65%), and supported collaboration (62%).

CONCLUSION

Clinicians were able to use a SDM tool in the care of patients with thyroid nodules. Although they wished it were more flexible, they found on the whole that its use in the clinical encounter was beneficial to patients and clinicians.

Association between Hashimoto's thyroiditis and melanoma: a retrospective matched cohort study

An inflammatory microenvironment has been shown to increase risk for malignant melanoma, suggesting that melanoma may be related to a pro-inflammatory state. Though Hashimoto's thyroiditis is one of the most common autoimmune diseases, there are no investigations of its relationship with melanoma. We aim to determine if Hashimoto's increases risk of developing melanoma. A retrospective, validated cohort of patients with a diagnosis of Hashimoto's between 2005 and 2020 were identified using the Olmsted County database. Patients were age and sex matched to controls without a Hashimoto's diagnosis. The primary outcomes were development of melanoma and time to first melanoma diagnosis. 4805 patients were included in the study, with 1726 (36%) having a diagnosis of Hashimoto's. Hashimoto's patients had no significant difference in risk of melanoma (relative risk 0.96, 95% CI 0.78-1.17) or nonmelanoma skin cancer (relative risk 0.95, 95% CI 0.86-1.06) compared with matched controls. This suggests that the local proinflammatory environment present in Hashimoto's does not contribute significantly to melanoma risk. Larger studies may be needed to further characterize the relationship between these diseases.

Patient feedback receiving care using a shared decision making tool for thyroid nodule evaluation-an observational study

PURPOSE

To characterize the feedback of patients with thyroid nodules receiving care using a shared decision making (SDM) tool designed to improve conversations with their clinicians related to diagnostic options (e.g. thyroid biopsy, ultrasound surveillance).

METHODS

Investigators qualitatively analyzed post-encounter interviews with patients to characterize their feedback of a SDM tool used during their clinical visits. Additionally, investigators counted instances of diagnostic choice awareness and of patients' expression of a diagnostic management preference in recordings of clinical encounters of adult patients presenting for evaluation of thyroid nodules in which the SDM tool was used.

RESULTS

In total, 53 patients (42 (79%) women); median age 62 years were enrolled and had consultations supported by the SDM tool. Patients were favorable about the design of the SDM tool and its ability to convey information about options and support patient-clinician interactions. Patients identified opportunities to improve the tool through adding more content and improve its use in practice through training of clinicians in its use. There was evidence of diagnostic choice awareness in 52 (98%) of these visits and patients expressed a diagnostic management preference in 40 (76%).

CONCLUSION

User centered design including feedback from patients and real life observation supports the use of the SDM tool to facilitate collaboration between patients and clinicians.

PSAT245 Feasibility of introducing a conversation aid for patients with thyroid nodules in clinical practice: Understanding the clinician experience

Background

To support the collaboration between patients with thyroid nodules and their clinician, we developed a Thyroid NOdule conversation aid (TNOC). TNOC includes a representation of thyroid cancer risk, alternative management options, and a print-out summary for patients. In a pilot study, the use of TNOC was associated with improvement in the quality of diagnostic conversations.

Research question: The aim of this study was to evaluate the feasibility of introducing TNOC into clinical encounters and understand clinicians’ experience with its use.

Methods

Prospective study conducted in two academic centers in the U.S. We included adult patients with thyroid nodules and their clinicians (endocrinologists and ear, nose, and throat specialists (ENT)). The feasibility of introducing TNOC was evaluated by the fidelity to which TNOC was used (12 item checklist of included components, such as: thyroid cancer risk presentation, management options) and the duration of clinical visits, evaluated through video recordings. Clinicians completed a post-visit survey to evaluate how helpful and easy to use TNOC was and the degree to which it supported collaboration with their patients. A qualitative analysis of semi-structured interviews was conducted after clinicians used TNOC in at least three visits. The interview guide was developed following constructs included in the Consolidated Framework for Implementation Research. Analysis was conducted using the constant comparative method.

Results

Twelve clinicians (9 endocrinologists and 3 ENT) were included and used TNOC with 53 patients. Most patients were women (N -42, 79%) with a median age of 62 years (Interquartile range, 53-70). The median size of the thyroid nodules was 2.3 cm (Interquartile range, 1.3, 3.0). The median clinical visit duration was 17 minutes (Interquartile range 10,28). The median fidelity score was 75% (interquartile range 58, 75), with thyroid cancer risk presentation being the most commonly used item (98%) and the printable summary the least used (15%). Clinicians agreed or strongly agreed that TNOC was helpful (N=34, 65%), easy to use (N=44, 85%), and supported collaboration with patients (N= 32, 62%).

In the qualitative analysis, clinicians reported that TNOC was organized and covered commonly discussed topics. Moreover, the use of TNOC could support the clinical interaction and be beneficial for patients by assuring the patient perspective was considered, creating space for questions, and improving how information was presented. Yet, the perceived benefit of using TNOC was expected to be different depending on the expertise of the clinician, as experts might benefit less. Clinicians highlighted the importance of familiarity with TNOC to ease its use and suggested modifications: additional visual content, improved navigation to support dynamic use and providing patient access before/after the visit.

Interpretation: Using TNOC to support thyroid nodule management conversations was feasible, helpful, easy to use, and supportive of patient-clinician collaboration.

Presentation: Saturday, June 11, 2022 1:00 p.m. - 3:00 p.m.

Clinician Agreement on the Classification of Thyroid Nodules Ultrasound Features: A Survey of 2 Endocrine Societies

CONTEXT

Thyroid nodule risk stratification allows clinicians to standardize the evaluation of thyroid cancer risk according to ultrasound features.

OBJECTIVE

To evaluate interrater agreement among clinicians assessing thyroid nodules ultrasound features and thyroid cancer risk categories.

DESIGN, SETTING, AND PARTICIPANTS

We surveyed Endocrine Society and Latin American Thyroid Society members to assess their interpretation of composition, echogenicity, shape, margins, and presence of echogenic foci of 10 thyroid nodule cases. The risk category for thyroid cancer was calculated following the American College of Radiology-Thyroid Imaging Reporting & Data System (ACR-TIRADS) framework from individual responses.

MAIN OUTCOMES AND MEASURES

We used descriptive statistics and Gwet's agreement coefficient (AC1) to assess the primary outcome of interrater agreement for ACR-TIRADS risk category. As secondary outcomes, the interrater agreement for individual features and a subgroup analysis of interrater agreement for the ACR-TIRADS category were performed (ultrasound reporting system, type of practice, and number of monthly appraisals).

RESULTS

A total of 144 participants were included, mostly endocrinologists. There was moderate level of agreement for the absence of echogenic foci (AC1 0.53, 95% CI 0.24-0.81) and composition (AC1 0.54, 95% CI 0.36-0.71). The agreement for margins (AC1 0.24, 95% CI 0.15-0.33), echogenicity (AC1 0.34, 95% CI 0.22-0.46), and shape assessment (AC1 0.42, 95% CI 0.13-0.70) was lower. The overall agreement for ACR-TIRADS assessment was AC1 0.29, (95% CI 0.13-0.45). The AC1 of ACR-TIRADS among subgroups was similar.

CONCLUSIONS

This study found high variation of judgments about ACR-TIRADS risk category and individual features, which poses a potential challenge for the widescale implementation of thyroid nodule risk stratification.

Nonsurgical Management of Thyroid Nodules: The Role of Ablative Therapies

CONTEXT

After a thorough evaluation most thyroid nodules are deemed of no clinical consequence and can be observed. However, when they are compressive, toxic, or involved by papillary thyroid carcinoma surgery or radioactive iodine (RAI) (if toxic) are the treatments of choice. Both interventions can lead to hypothyroidism and other adverse outcomes (eg, scar, dysphonia, logistical limitation with RAI). Active surveillance might be used for papillary thyroid microcarcinoma (PTMC) initially, but anxiety leads many cases to surgery later. Several ablative therapies have thus evolved over the last few years aimed at treating these nodules while avoiding described risks.

CASES

We present 4 cases of thyroid lesions causing concern (compressive symptoms, thyrotoxicosis, anxiety with active surveillance of PTMC). The common denominator is patients' attempt to preserve thyroid function, bringing into focus percutaneous ethanol injection (PEI) and thermal ablation techniques (radiofrequency ablation [RFA] being the most common). We discuss the evidence supporting these approaches and compare them with standard therapy, where evidence exists. We discuss additional considerations for the utilization of these therapies, their side-effects, and conclude with a simplified description of how these procedures are performed.

CONCLUSION

Thermal ablation, particularly RFA, is becoming an attractive option for managing a subgroup of solid thyroid nodules, while PEI has a role in managing thyroid cysts and a select group of PTMC. Their role in the algorithm of thyroid nodule management is still being refined and technical expertise will be essential to reproduce the reported results into everyday practice.

A novel method for causal structure discovery from EHR data and its application to type-2 diabetes mellitus

Modern AI-based clinical decision support models owe their success in part to the very large number of predictors they use. Safe and robust decision support, especially for intervention planning, requires causal, not associative, relationships. Traditional methods of causal discovery, clinical trials and extracting biochemical pathways, are resource intensive and may not scale up to the number and complexity of relationships sufficient for precision treatment planning. Computational causal structure discovery (CSD) from electronic health records (EHR) data can represent a solution, however, current CSD methods fall short on EHR data. This paper presents a CSD method tailored to the EHR data. The application of the proposed methodology was demonstrated on type-2 diabetes mellitus. A large EHR dataset from Mayo Clinic was used as development cohort, and another large dataset from an independent health system, M Health Fairview, as external validation cohort. The proposed method achieved very high recall (.95) and substantially higher precision than the general-purpose methods (.84 versus .29, and .55). The causal relationships extracted from the development and external validation cohorts had a high (81%) overlap. Due to the adaptations to EHR data, the proposed method is more suitable for use in clinical decision support than the general-purpose methods.

Favorable Early Outcomes With Thyroid Lobectomy for Low-Risk Papillary Thyroid Cancer: The Mayo Clinic Experience

BACKGROUND

Until 2015, standard of care for low-risk papillary thyroid cancer (PTC) >1 cm was a total or near-total thyroidectomy. Despite changes in guidelines and surgical management of low-risk PTC since 2015, little data are available regarding the effect on the need for additional surgery or risk for development of lymph node metastases. Our aim was to determine outcomes in patients who underwent initial thyroid lobectomy for low-risk PTC at a high-volume tertiary care institution.

METHODS

Retrospective review of patients ≥18 years old with biopsy proven low-risk PTC 1-4 cm who underwent partial thyroidectomy (eg, lobectomy/isthmusectomy) at Mayo Clinic, Rochester, MN, between March 2016 and June 30, 2019.

RESULTS

From 1481 thyroidectomies performed during study period, 940 contained PTC on final pathology. Of these, 87 (of 123) patients who had an initial thyroid lobectomy met inclusion criteria. Five (6%) of these patients proceeded to completion thyroidectomy (CT), with 3 requiring CT and radioactive iodine in the first postoperative year and 2 undergoing only CT in the second postoperative year. No postoperative complications were reported. No patient in this cohort required additional surgery or treatment for newly discovered lymph node metastases during the follow-up period. 43 (of 72, 60%) patients not on thyroxine therapy preoperatively were started on thyroxine therapy postoperatively.

CONCLUSIONS

Early outcomes for those undergoing thyroid lobectomy for low-risk PTC at our institution have been favorable. These results support the 2015 American Thyroid Association guidelines to offer lobectomy for those with low-risk PTC 1-4 cm.

Thyroid Nodule Size as a Predictor of Malignancy in Follicular and Hurthle Neoplasms

INTRODUCTION

The management of follicular (FN) and Hurthle cell neoplasms (HCN) is often difficult because of the uncertainty of malignancy risk. We aimed to assess characteristics of benign and malignant follicular and Hurthle neoplasms based on their shape and size.

MATERIALS AND METHODS

Patients with Follicular adenoma (FA) or carcinoma (FC) and Hurthle Cell adenoma (HCA) or carcinoma (HCC) who had preoperative ultrasonography were included. Demographic data were retrieved. Size and shape of the nodules were measured. Logistic regression analyses and odds ratios were performed.

RESULTS

A total of 115 nodules with 57 carcinomas and 58 adenomas were included. Logistic regression analysis shows that the nodule height and the patient age are predictors of malignancy (p-values = 0.001 and 0.042). A cutoff value of nodule height ≥ 4 cm. produces an odds ratio of 4.5 (p-value = 0.006). An age ≥ 55 year-old demonstrates an odds ratio of 2.4-3.6 (p-value = 0.03). Taller-than-wide shape was not statistically significant (p-value = 0.613).

CONCLUSION

FC and HCC are larger than FA and HCA in size, with a cutoff at 4 cm. Increasing age increases the odds of malignancy with a cutoff at 55 year-old. Taller-than-wide shape is not a predictor of malignancy.

A Computational Method for Learning Disease Trajectories From Partially Observable EHR Data

Diseases can show different courses of progression even when patients share the same risk factors. Recent studies have revealed that the use of trajectories, the order in which diseases manifest throughout life, can be predictive of the course of progression. In this study, we propose a novel computational method for learning disease trajectories from EHR data. The proposed method consists of three parts: first, we propose an algorithm for extracting trajectories from EHR data; second, three criteria for filtering trajectories; and third, a likelihood function for assessing the risk of developing a set of outcomes given a trajectory set. We applied our methods to extract a set of disease trajectories from Mayo Clinic EHR data and evaluated it internally based on log-likelihood, which can be interpreted as the trajectories' ability to explain the observed (partial) disease progressions. We then externally evaluated the trajectories on EHR data from an independent health system, M Health Fairview. The proposed algorithm extracted a comprehensive set of disease trajectories that can explain the observed outcomes substantially better than competing methods and the proposed filtering criteria selected a small subset of disease trajectories that are highly interpretable and suffered only a minimal (relative 5%) loss of the ability to explain disease progression in both the internal and external validation.

Characterization of Thyroid Disease Prevalence Among Transgender and Gender-Diverse Patients

Objective: Transgender and gender-diverse individuals are at risk of insufficient treatment of endocrine diseases due to a number of barriers to care. There are currently no data evaluating the prevalence of thyroid disease in this population, and it is unknown if gender-affirming hormone therapy affects treatment of thyroid disease in these individuals. Methods: Utilizing a registry of 676 patients over 18 years of age who were seen in our Transgender and Intersex Specialty Care Clinic from 2015-2019, we identified 554 individuals seeking medical therapy for gender dysphoria/incongruence. Of these, 56 patients were taking thyroid hormone or antithyroid medications or had a coded diagnosis of thyroid disease; 2 were excluded as they were receiving thyroid hormone as adjunctive therapy for refractory depression. 54 patients were therefore analyzed with respect to thyroid disease (TD+), and compared to those 498 patients without thyroid disease (TD-) with regard to average vital signs, demographics, and presence of common comorbidities. Results: Fifty percent of our TD+ patients were recorded female sex at birth, and 98% were Caucasian. TD+ patients were much more likely to have essential hypertension (OR 5.99), to use tobacco (OR 2.23), and to be overweight or obese (OR 2.16) than TD- patients. Due to the evolving natural history of disease, some TD+ patients belonged to multiple categories: 48 patients, 26 trans feminine and 21 trans masculine, had hypothyroidism, of whom 41 had overt hypothyroidism and 2 patients had subacute thyroiditis that progressed to the hypothyroid phase of illness. 5 patients (3 trans masculine and 2 trans feminine) demonstrated hyperthyroidism, 4 of whom had Graves’ Disease. 2 patients had multinodular goiter, both trans masculine. 2 patients had thyroid malignancies, both trans feminine, of whom one had proven follicular thyroid carcinoma and the other had unspecified thyroid malignancy. Among hypothyroid patients, there was a slight non-significant trend toward increased thyroid hormone requirements while receiving treatment with estradiol or testosterone. Conclusion: To our knowledge, this represents the first attempt to characterize the prevalence of various thyroid disease states in the gender diverse population. Our data corresponded to a prevalence of hypothyroidism of approximately 8.7%, which is higher than previously published estimates of 3-5% in the general population. Whether this represents actual increased prevalence or assessment bias is uncertain. It is important for all health professionals who care for gender diverse people to identify and appropriately treat thyroid disease, and to monitor thyroid function closely if gender-affirming hormone therapy is initiated.

Predicting Outcomes in Sporadic and Hereditary Medullary Thyroid Carcinoma over Two Decades

Background: Medullary thyroid cancer (MTC) can be associated with significant morbidity and mortality in advanced cases. Hence, we aimed to identify factors at the time of MTC surgery that predict overall survival (OS), disease-specific survival (DSS), locoregional recurrence/persistence (LR), and distant metastases (DM). Methods: We performed a retrospective study of clinicopathologic, radiological, and laboratory data in MTC patients who underwent thyroidectomy at Mayo Clinic from January 1995 to December 2015. Results: We identified 163 patients (mean age 48.4 years, 48% males), 102 with sporadic MTC and 61 with hereditary disease (n = 46 multiple endocrine neoplasia [MEN] 2A, n = 3 MEN 2B, n = 12 familial MTC) with a median follow-up time of 5.5 years. On univariate analysis, age >55 years, male sex, DM at the time of surgery (M1), lateral neck lymph node (LN) involvement (N1b), gross extrathyroidal extension (ETE), American Joint Committee on Cancer (AJCC) stage 3/4, tumor size (T) 3/4, tumor size, and postoperative calcitonin (Ctn) and carcinoembryonic antigen (CEA) were significant predictors of worse OS and DSS. On multivariable analysis, both gross ETE (hazard ratio [HR] 4.62, 6.58) and M1 (HR 5.11, 10.45) remained significant predictors of worse OS as well as DSS, while age >55 years (HR 3.21), male sex (HR 2.42), and postoperative Ctn (HR 1.002 for every 100 pg/mL increase) were significant only for worse OS. On univariate analysis, male sex, M1, N1b, gross ETE, stage 3/4, T 3/4, tumor size, number of LNs involved, and postoperative Ctn were significant predictors of LR and DM; age >55 years was additionally significant for DM. On multivariable analysis, gross ETE (HR 3.16, 5.93) and N1b (HR 4.31, 4.64) remained significant predictors of LR and DM; ratio of resected/involved LN (HR 10.91) was additionally predictive for LR and postoperative Ctn (HR 1.003 for every 100 pg/mL increase) for DM. Conclusions: Disease burden at initial surgery, especially gross ETE, lateral neck LN involvement, and DM, as well as the biochemical response to surgery appear to be more important than demographic factors in terms of MTC prognosis. These findings highlight the importance of rigorous perioperative assessment to better predict MTC outcomes.

PANCYTOPENIA SECONDARY TO AUTOIMMUNE VITAMIN B12 DEFICIENCY IN GRAVES DISEASE

Objective

To describe a case of Graves disease (GD) and coexistent pancytopenia associated with autoimmune vitamin B₁₂ deficiency. While thyrotoxicosis and antithyroid drugs can cause pancytopenia, other autoimmune conditions such as vitamin B₁₂ deficiency can occur, leading to severe anemia and pancytopenia.

Methods

A 19-year-old female with GD treated with methimazole presented with thyrotoxicosis and evidence of pancytopenia. Diagnostic studies included a complete blood cell count, peripheral blood smears, thyroid function tests, and a bone marrow biopsy.

Results

White blood cells were 2.4 × 10⁹ cells/L (reference range [RR] is 3.4 to 9.6 × 10⁹ cells/L), hemoglobin was 7.9 g/dL (RR is 11.6 to 15.0 g/dL), neutrophil count was 1.2 × 10⁹ cells/L, and platelets were 84 × 10⁹ cells/L (RR is 157 to 371 × 10⁹ cells/L). Thyroid-stimulating hormone was <0.01 mIU/L (RR is 0.50 to 4.30 mIU/L), free thyroxine was 3.7 ng/dL (RR is 1.0 to 1.6 ng/dL), and total triiodothyronine was 221 ng/dL (RR is 91 to 218 ng/dL). Due to suspicion for drug-induced pancytopenia, methimazole was discontinued. Three days later, she was hospitalized for a syncopal episode with a further decline in hemoglobin to 6.7 g/dL, neutrophils to 0.68 × 10⁹ cells/L, and platelets to 69 × 10⁹ cells/L. Bone marrow biopsy findings showing marrow hypercellularity and hypersegmented neutrophils suggested vitamin B₁₂ deficiency. Vitamin B₁₂ was <70 ng/L (RR is 180 to 914 ng/L). Intramuscular vitamin B₁₂ injections were initiated, and pancytopenia resolved within 1 month.

Conclusion

Although rarely described in the literature, autoimmune vitamin B₁₂ deficiency can be missed as an underlying etiology for pancytopenia in patients with GD. The clinical picture can be further confounded when these patients are treated with antithyroid drugs known to cause bone marrow suppression.

Long-Term Results of Treating With Ethanol Ablation 15 Adult Patients With cT1aN0 Papillary Thyroid Microcarcinoma

Background

Currently acceptable management options for patients with adult papillary thyroid microcarcinoma (APTM) range from immediate surgery, either unilateral lobectomy or bilateral lobar resection, to active surveillance (AS). An alternative minimally invasive approach, originally employed for eliminating neck nodal metastases, may be ultrasound-guided percutaneous ethanol ablation (EA). Here we present our experience of definitively treating with EA 15 patients with APTM.

Patients and Methods

During 2010 through 2017, the 15 cT1aN0M0 patients selected for EA were aged 36 to 86 years (median, 45 years). Tumor volumes (n = 17), assessed by sonography, ranged from 25 to 375 mm³ (median, 109 mm³). Fourteen of 15 patients had 2 ethanol injections on successive days; total volume injected ranged from 0.45 to 1.80 cc (median, 1.1 cc). All ablated patients were followed with sonography and underwent recalculation of tumor volume and reassessment of tumor perfusion at each follow-up visit.

Results

The ablated patients have now been followed for 10 to 100 months (median, 64 months). There were no complications and no ablated patient developed postprocedure recurrent laryngeal nerve dysfunction. All 17 ablated tumors shrank (median 93%) and Doppler flow eliminated. Median tumor volume reduction in 9 identifiable avascular foci was 82% (range, 26%-93%). After EA, 8 tumors (47%) disappeared on sonography after a median of 10 months. During follow-up no new PTM foci and no nodal metastases have been identified.

Conclusions

Definitive treatment of APTM by EA is effective, safe, and inexpensive. Our results suggest that, for APTM patients who do not wish neck surgery and are uncomfortable with AS, EA represents a well-tolerated and minimally invasive outpatient management option.

Frequent Causal Pattern Mining: A Computationally Efficient Framework For Estimating Bias-Corrected Effects

Our aging population increasingly suffers from multiple chronic diseases simultaneously, necessitating the comprehensive treatment of these conditions. Finding the optimal set of drugs for a combinatorial set of diseases is a combinatorial pattern exploration problem. Association rule mining is a popular tool for such problems, but the requirement of health care for finding causal, rather than associative, patterns renders association rule mining unsuitable. To address this issue, we propose a novel framework based on the Rubin-Neyman causal model for extracting causal rules from observational data, correcting for a number of common biases. Specifically, given a set of interventions and a set of items that define subpopulations (e.g., diseases), we wish to find all subpopulations in which effective intervention combinations exist and in each such subpopulation, we wish to find all intervention combinations such that dropping any intervention from this combination will reduce the efficacy of the treatment. A key aspect of our framework is the concept of closed intervention sets which extend the concept of quantifying the effect of a single intervention to a set of concurrent interventions. Closed intervention sets also allow for a pruning strategy that is strictly more efficient than the traditional pruning strategy used by the Apriori algorithm. To implement our ideas, we introduce and compare five methods of estimating causal effect from observational data and rigorously evaluate them on synthetic data to mathematically prove (when possible) why they work. We also evaluated our causal rule mining framework on the Electronic Health Records (EHR) data of a large cohort of 152000 patients from Mayo Clinic and showed that the patterns we extracted are sufficiently rich to explain the controversial findings in the medical literature regarding the effect of a class of cholesterol drugs on Type-II Diabetes Mellitus (T2DM).

Predicting diabetes clinical outcomes using longitudinal risk factor trajectories

BACKGROUND

The ubiquity of electronic health records (EHR) offers an opportunity to observe trajectories of laboratory results and vital signs over long periods of time. This study assessed the value of risk factor trajectories available in the electronic health record to predict incident type 2 diabetes.

STUDY DESIGN AND METHODS

Analysis was based on a large 13-year retrospective cohort of 71,545 adult, non-diabetic patients with baseline in 2005 and median follow-up time of 8 years. The trajectories of fasting plasma glucose, lipids, BMI and blood pressure were computed over three time frames (2000-2001, 2002-2003, 2004) before baseline. A novel method, Cumulative Exposure (CE), was developed and evaluated using Cox proportional hazards regression to assess risk of incident type 2 diabetes. We used the Framingham Diabetes Risk Scoring (FDRS) Model as control.

RESULTS

The new model outperformed the FDRS Model (.802 vs .660; p-values <2e-16). Cumulative exposure measured over different periods showed that even short episodes of hyperglycemia increase the risk of developing diabetes. Returning to normoglycemia moderates the risk, but does not fully eliminate it. The longer an individual maintains glycemic control after a hyperglycemic episode, the lower the subsequent risk of diabetes.

CONCLUSION

Incorporating risk factor trajectories substantially increases the ability of clinical decision support risk models to predict onset of type 2 diabetes and provides information about how risk changes over time.

Thyroid nodules: diagnostic evaluation based on thyroid cancer risk assessment

Thyroid nodules are extremely common and can be detected by sensitive imaging in more than 60% of the general population. They are often identified in patients without symptoms who are undergoing evaluation for other medical complaints. Indiscriminate evaluation of thyroid nodules with thyroid biopsy could cause a harmful epidemic of diagnoses of thyroid cancer, but inadequate selection of thyroid nodules for biopsy can lead to missed diagnoses of clinically relevant thyroid cancer. Recent clinical guidelines advocate a more conservative approach in the evaluation of thyroid nodules based on risk assessment for thyroid cancer, as determined by clinical and ultrasound features to guide the need for biopsy. Moreover, newer evidence suggests that for patients with indeterminate thyroid biopsy results, a combined assessment including the initial ultrasound risk stratification or other ancillary testing (molecular markers, second opinion on thyroid cytology) can further clarify the risk of thyroid cancer and the management strategies. This review summarizes the clinical importance of adequate evaluation of thyroid nodules, focuses on the clinical evidence for diagnostic tests that can clarify the risk of thyroid cancer, and highlights the importance of considering the patient's values and preferences when deciding on management strategies in the setting of uncertainty about the risk of thyroid cancer.

The Levothyroxine Absorption Test: A Four-Year Experience (2015-2018) at The Mayo Clinic

Background: Levothyroxine (LT4) is the mainstay of therapy for hypothyroidism. Yet, despite physician efforts at dose titration, some patients remain hypothyroid on LT4 doses in excess of weight-based calculations, a condition known as refractory hypothyroidism. The LT4 absorption test (LT4AT) has been proposed to have utility in these patients by enabling distinction of LT4 malabsorption from pseudomalabsorption, a condition of intentional nonadherence. Given its rare use in clinical practice, we reviewed our institution's experience with the LT4AT to assess its impact on management of refractory hypothyroidism. Methods: We reviewed the charts of 16 patients diagnosed with refractory hypothyroidism and who had completed the LT4AT between January 2015 to January 2019. The primary aim was to determine the utility of this test in distinguishing LT4 malabsorption from pseudomalabsorption. Secondary aims were to determine whether the results of this test impacted physicians' management decisions, as well as to report on clinical outcomes at follow-up. Our LT4AT is a six-hour test wherein patients receive a weight-based dose of LT4 followed by serial measurements of total thyroxine (TT4) and thyrotropin (TSH). Percentage absorption is calculated using the following formula, with normal absorption being ≥60%: [Formula: see text] Results: Percentage absorption was calculated in 13 of 16 patients due to lack of TT4 data for 3 patients. Absorption was impaired in one patient (% absorbed = 0), who had known causes of malabsorption. The remaining 12 patients had normal absorption by hour 4 of the test (% absorption 60-158) in conjunction with upward TT4 trends. Clinical follow-up ranged from 1 to 32 months (median 6.5 months), with 11 patients having follow-up data. Six of these had normal or suppressed TSH values at most recent follow-up, and four had improved but persistent TSH elevations. The one said patient with malabsorption improved with intravenous LT4. Conclusions: The LT4AT can provide valuable information for distinguishing malabsorption from pseudomalabsorption. Our findings support the combined use of calculated percentage absorptions with TT4 trends for at least a four-hour time frame when making determinations regarding absorption.

Evaluating the Impact of Data Representation on EHR-Based Analytic Tasks

Different analytic techniques operate optimally with different types of data. As the use of EHR-based analytics expands to newer tasks, data will have to be transformed into different representations, so the tasks can be optimally solved. We classified representations into broad categories based on their characteristics, and proposed a new knowledge-driven representation for clinical data mining as well as trajectory mining, called Severity Encoding Variables (SEVs). Additionally, we studied which characteristics make representations most suitable for particular clinical analytics tasks including trajectory mining. Our evaluation shows that, for regression, most data representations performed similarly, with SEV achieving a slight (albeit statistically significant) advantage. For patients at high risk of diabetes, it outperformed the competing representation by (relative) 20%. For association mining, SEV achieved the highest performance. Its ability to constrain the search space of patterns through clinical knowledge was key to its success.

CLINICAL RECOGNITION AND MANAGEMENT OF PATIENTS WITH PREDIABETES

Objective: Early identification and management of prediabetes is critical to prevent progression to diabetes. We aimed to assess whether prediabetes is appropriately recognized and managed among patients with impaired fasting glucose (IFG). Methods: We carried out an observational study of Olmsted County residents evaluated at the Mayo Clinic between 1999-2017. We randomly selected 108 subjects with biochemical criteria of IFG and 105 normoglycemic subjects. We reviewed their health records at baseline (1999-2004) and during follow up (2005-2017) collecting demographic and clinical data including vitals, diagnoses, laboratory, and medications associated with cardiovascular comorbidities. The main outcome was documentation of any recognition of prediabetes and management recommendations (lifestyle changes and/or medications). Results: At baseline (1999-2004), 26.85% (29/108) of subjects with IFG were recognized as having prediabetes, and of these 75.86% (22/29) received management recommendations with 6.9% (2/29) getting metformin. During follow-up (2005-2017), 26.67% (28/105) of initial cohort of normoglycemic subjects developed incident IFG and of these, 85.71% (24/28) were recognized as having prediabetes, and 58.33% (14/24) received management recommendations. During the entire study period, 62.50% (85/136) were recognized as having prediabetes of which 75.29% (64/85) had documented management recommendations. High body mass index (BMI) (≥35) was associated with increased recognition (odds ratio [OR] 3.66; confidence interval [CI] 1.065, 12.500; P = .0395), and normal BMI (<25) was associated with a lack of recognition (OR 0.146; CI 0.189, 0.966; P = .0413). Conclusion: Despite evidence supporting the efficacy of lifestyle changes and medications in managing prediabetes, this condition is not fully recognized in routine clinical practice. Increased awareness of diagnostic criteria and appropriate management are essential to enhance diabetes prevention. Abbreviations: BMI = body mass index; CI = confidence interval; EHR = electronic health records; FBG = fasting blood glucose; IFG = impaired fasting glucose; IGT = impaired glucose tolerance; OR = odds ratio.

Ethanol Ablation for the Treatment of Cystic and Predominantly Cystic Thyroid Nodules

OBJECTIVE

To determine the efficacy and safety of percutaneous ethanol injection (PEI) for the treatment of symptomatic cystic thyroid nodules.

PATIENTS AND METHODS

Retrospective analysis of patients with benign cystic thyroid nodules treated with PEI from February 1, 2000, through October 31, 2016. The main outcomes were efficacy, defined as symptom relief or reduction in nodule volume of 50% or more, and safety, defined as no or minor adverse events.

RESULTS

Twenty patients had PEI. Mean age at the time of PEI was 50 years, and 13 (65%) were women; all patients were euthyroid. Twelve patients (60%) had complex cystic thyroid nodules (>50% cystic component), with the rest being purely cystic. The median largest diameter of the thyroid cyst was 4.5 cm (interquartile range [IQR], 3.2-5.3 cm; range, 2.3-8.0 cm); the median volume pre-PEI was 19.6 mL (IQR, 10.4-48.5 mL; range, 2.8-118.1 mL). The median amount of cystic fluid drained before PEI was 13.5 mL (IQR, 6.8-32.3 mL), and the median amount of ethanol administered was 3 mL (IQR, 2-5 mL; range, 0.5-20 mL). After median follow-up of 2 years, 17 of 19 patients (89%) were asymptomatic. Of 10 patients with available imaging on follow-up, 7 (70%) had a 50% or greater reduction in nodule volume (median volume decrease, 75.64% [IQR, 41.40%-91.99%]). Adverse effects occurred in 4 patients (20%) and were mild and temporary (slight pain, vagal reaction, and bleeding into the cyst).

CONCLUSION

Percutaneous ethanol injection seems to be a safe and effective alternative to surgical resection for patients with purely or predominantly cystic thyroid nodules and compressive symptoms who decline surgery or are not good surgical candidates.

Outcomes of Radiofrequency Ablation Therapy for Large Benign Thyroid Nodules: A Mayo Clinic Case Series

OBJECTIVE

To assess the effectiveness, tolerability, and complications of radiofrequency ablation (RFA) in patients with benign large thyroid nodules (TNs).

PATIENTS AND METHODS

This is a retrospective review of 14 patients with predominantly solid TNs treated with RFA at Mayo Clinic in Rochester, Minnesota, from December 1, 2013, through October 30, 2016. All the patients declined surgery or were poor surgical candidates. The TNs were benign on fine-needle aspiration, enlarging or causing compressive symptoms, and 3 cm or larger in largest diameter. We evaluated TN volume, compressive symptoms, cosmetic concerns, and thyroid function.

RESULTS

Median TN volume reduction induced by RFA was 44.6% (interquartile range [IQR], 42.1%-59.3%), from 24.2 mL (IQR, 17.7-42.5 mL) to 14.4 mL (IQR, 7.1-19.2 mL) (P<.001). Median follow-up was 8.6 months (IQR, 3.9-13.9 months). Maximum results were achieved by 6 months. Radiofrequency ablation did not affect thyroid function. In 1 patient with subclinical hyperthyroidism due to toxic adenoma, thyroid function normalized 4 months after ablation of the toxic nodule. Compressive symptoms resolved in 8 of 12 patients (67%) and improved in the other 4 (33%). Cosmetic concerns improved in all 8 patients. The procedure had no sustained complications.

CONCLUSION

In this population, RFA of benign large TNs performed similarly to the reports from Europe and Asia. It induces a substantial volume reduction of predominantly solid TNs, improves compressive symptoms and cosmetic concerns, and does not affect normal thyroid function. Radiofrequency ablation has an acceptable safety profile and should be considered as a low-risk alternative to conventional treatment of symptomatic benign TNs.

An Online Survey of Hypothyroid Patients Demonstrates Prominent Dissatisfaction

BACKGROUND

Approximately 15% more patients taking levothyroxine (LT4) report impaired quality of life compared to controls. This could be explained by additional diagnoses independently affecting quality of life and complicating assignment of causation. This study sought to investigate the underpinnings of reduced quality of life in hypothyroid patients and to provide data for discussion at a symposium addressing hypothyroidism.

METHODS

An online survey for hypothyroid patients was posted on the American Thyroid Association Web site and forwarded to multiple groups. Respondents were asked to rank satisfaction with their treatment for hypothyroidism and their treating physician. They also ranked their perception regarding physician knowledge about hypothyroidism treatments, need for new treatments, and life impact of hypothyroidism on a scale of 1-10. Respondents reported the therapy they were taking, categorized as LT4, LT4 and liothyronine (LT4 + LT3), or desiccated thyroid extract (DTE). They also reported sex, age, cause of hypothyroidism, duration of treatment, additional diagnoses, and prevalence of symptoms.

RESULTS

A total of 12,146 individuals completed the survey. The overall degree of satisfaction was 5 (interquartile range [IQR] = 3-8). Among respondents without self-reported depression, stressors, or medical conditions (n = 3670), individuals taking DTE reported a higher median treatment satisfaction of 7 (IQR = 5-9) compared to other treatments. At the same time, the LT4 treatment group exhibited the lowest satisfaction of 5 (IQR = 3-7), and for the LT4 + LT3 treatment group, satisfaction was 6 (IQR = 3-8). Respondents taking DTE were also less likely to report problems with weight management, fatigue/energy levels, mood, and memory compared to those taking LT4 or LT4 + LT3.

CONCLUSIONS

A subset of patients with hypothyroidism are not satisfied with their current therapy or their physicians. Higher satisfaction with both treatment and physicians is reported by those patients on DTE. While the study design does not provide a mechanistic explanation for this observation, future studies should investigate whether preference for DTE is related to triiodothyronine levels or other unidentified causes.

Multi-Task Learning to Identify Outcome-Specific Risk Factors that Distinguish Individual Micro and Macrovascular Complications of Type 2 Diabetes

Because deterioration in overall metabolic health underlies multiple complications of Type 2 Diabetes Mellitus, a substantial overlap among risk factors for the complications exists, and this makes the outcomes difficult to distinguish. We hypothesized each risk factor had two roles: describing the extent of deteriorating overall metabolic health and signaling a particular complication the patient is progressing towards. We aimed to examine feasibility of our proposed methodology that separates these two roles, thereby, improving interpretation of predictions and helping prioritize which complication to target first. To separate these two roles, we built models for six complications utilizing Multi-Task Learning-a machine learning technique for modeling multiple related outcomes by exploiting their commonality-in 80% of EHR data (N=9,793) from a university hospital and validated them in remaining 20% of the data. Additionally, we externally validated the models in claims and EHR data from the OptumLabs™ Data Warehouse (N=72,720). Our methodology successfully separated the two roles, revealing distinguishing outcome-specific risk factors without compromising predictive performance. We believe that our methodology has a great potential to generate more understandable thus actionable clinical information to make a more accurate and timely prognosis for the patients.

Estimating Disease Onset Time by Modeling Lab Result Trajectories via Bayes Networks

The true onset time of a disease, particularly slow-onset diseases like Type 2 diabetes mellitus (T2DM), is rarely observable in electronic health records (EHRs). However, it is critical for analysis of time to events and for studying sequences of diseases. The aim of this study is to demonstrate a method for estimating the onset time of such diseases from intermittently observable laboratory results in the specific context of T2DM. A retrospective observational study design is used. A cohort of 5,874 non-diabetic patients from a large healthcare system in the Upper Midwest United States was constructed with a three-year follow-up period. The HbA1c level of each patient was collected from earliest and the latest follow-up. We modeled the patients' HbA1c trajectories through Bayesian networks to estimate the onset time of diabetes. Due to non-random censoring and interventions unobservable from EHR data (such as lifestyle changes), naïve modeling of HbA1c through linear regression or modeling time-to-event through proportional hazard model leads to a clinically infeasible model with no or limited ability to predict the onset time of diabetes. Our model is consistent with clinical knowledge and estimated the onset of diabetes with less than a six-month error for almost half the patients for whom the onset time could be clinically ascertained. To our knowledge, this is the first study of modeling long-term HbA1c progression in non-diabetic patients and estimating the onset time of diabetes.

Examining the Role of Preoperative Positron Emission Tomography/Computerized Tomography in Combination with Ultrasonography in Discriminating Benign from Malignant Cytologically Indeterminate Thyroid Nodules

BACKGROUND

Cytologically defined indeterminate thyroid nodules are a diagnostic challenge. Surgical lobectomy remains the gold standard for definitive diagnosis. However, 70-85% of nodules are ultimately benign. The primary objective of this study was to evaluate the negative predictive value (NPV) of F18-fluorodeoxyglucose (FDG) positron emission computed tomography (PET/CT) in excluding cancer among cytologically indeterminate thyroid nodules within the authors' institution using surgical pathology as the gold-standard reference. In addition, a systematic review was performed of published prospective studies on the NPV of PET/CT in evaluating indeterminate thyroid nodules.

METHODS

A retrospective review was performed of all patients aged ≥18 years seen at the Mayo Clinic between January 1, 2000, and December 31, 2014, with cytologically defined indeterminate thyroid nodules (suspicious for Hürthle cell neoplasm or follicular neoplasm; N = 858), who had a PET/CT within one year of fine-needle aspiration (n = 80) and underwent definitive diagnostic lobectomy (n = 51). Nodules were considered PET negative if they had a standardized uptake value (SUV) <5. Additionally, a systematic review was performed of published prospective studies on the NPV of PET/CT across multiple sites.

RESULTS

Fifty-one patients met the eligibility criteria. The retrospective review combined with a systematic review of eight prospective studies suggests that indeterminate nodules with a negative PET (SUV <5) have a low risk of malignancy (NPV 94%). The cancer prevalence in the institution is 14% and 27% in the combined prospective studies.

CONCLUSIONS

PET/CT represents a preoperative, non-invasive tool that when combined with sonographic features can identify indeterminate nodules at low risk for malignancy.

Risk of Malignancy in Thyroid Nodules with Non-Diagnostic Fine-Needle Aspiration: A Retrospective Cohort Study

BACKGROUND

Fine-needle aspiration (FNA) of thyroid nodules is commonly performed, and despite the use of ultrasound (US) guidance, the rate of non-diagnostic FNAs is still significant. The risk of malignancy of thyroid nodules with a non-diagnostic FNA is not clearly defined. However, most studies exclude the majority of patients without a repeat biopsy or surgery, thus increasing the likelihood of selection bias. The aims of this study were to determine the malignancy risk in nodules with an initial non-diagnostic FNA, and to identify the factors associated with malignancy.

METHODS

This was a retrospective cohort study of patients with thyroid nodules who underwent US-guided FNA between 2004 and 2010 and had a non-diagnostic result. Patients were followed until confirmatory diagnosis of the nature of the nodule was made. The outcome of malignant or benign disease was based on one of the following: (i) final surgical pathology following thyroidectomy; (ii) repeat biopsy; (iii) clinically, based on repeat ultrasound performed at least three years following biopsy; or (iv) report of thyroid status for patients without follow-up visits contacted by mail.

RESULTS

There were 699 nodules from 665 patients included. The mean age was 59 ± 15 years, and 71.7% were women. There was complete follow-up of 495 nodules. After a median follow-up of 2.7 years, thyroid cancer was found in 15 nodules. The prevalence of malignancy was 3% (15/495). The presence of nodular calcifications was the strongest predictor of thyroid malignancy (odds ratio 5.03 [confidence interval 1.8-14.7]). Initial nodule size was inversely associated with malignancy (odds ratio 0.55 [confidence interval 0.28-0.93]). However, the 193 patients without follow-up had smaller nodules compared with those included in the analysis. None of the patients with repeatedly non-diagnostic results were diagnosed with thyroid cancer at follow-up.

CONCLUSION

The prevalence of thyroid cancer in nodules with non-diagnostic results is lower than the malignancy rate in thyroid nodules in general, but not negligible. They should be followed as per guidelines with heightened suspicion for nodules containing calcifications. Nodules with repeatedly non-diagnostic FNA results especially in the absence of calcifications have a low risk of malignancy and may be observed.

Physical exam in asymptomatic people drivers the detection of thyroid nodules undergoing ultrasound guided fine needle aspiration biopsy

Understanding epidemiology and the factors leading to thyroid nodule diagnosis might help alter the course of the thyroid cancer epidemic. Population-based study using the Rochester Epidemiology Project database between 2003 and 2006. Patients with thyroid nodules who underwent ultrasound guided fine needle aspiration biopsy were included. We identified 453 patients with 520 thyroid nodules undergoing ultrasound guided fine needle aspiration. Patients were mostly women (n: 349, 77 %) with a mean age of 52 (standard deviation 17) years. The age-adjusted and sex-adjusted incidence of ultrasound guided fine needle aspiration-thyroid nodules between 2003 and 2006 was 89 (95 % confidence interval, 80-97) per 100,000 person-years; the incidence in women was 130 (95 % confidence interval, 117-144), and for men 43 (95 % confidence interval, 35-52) per 100,000 person-years. The incidence of ultrasound guided fine needle aspiration-thyroid nodules increased by 42 %, from 68 (95 % confidence interval, 54-82) in 2003 to 97 (95 % confidence interval, 80-113) per 100,000 person-years in 2006. The group with the highest incidence was patients between 70 and 79 years of age, 258 per 100,000 person-years. Most ultrasound guided fine needle aspiration-thyroid nodules were found in asymptomatic patients (n: 371, 82 %) by physical examination (n: 197, 43 %) or on imaging studies performed for non-thyroid issues (n: 108, 24 %). Women were more likely to have nodules detected by palpation (45 %), whereas imaging and physical examination contributed similarly in men (39 and 38 %). There is a large and rapid increase in the ultrasound guided fine needle aspiration-thyroid nodules, particularly among women and elderly patients which mirrors the trends observed in thyroid cancer. Most thyroid nodules were found in asymptomatic patients as a result of routine physical examination or imaging.

Thyroglobulin Measurement in Fine-Needle Aspiration Improves the Diagnosis of Cervical Lymph Node Metastases in Papillary Thyroid Carcinoma

BACKGROUND

Papillary thyroid carcinoma (PTC) is frequently associated with cervical lymph node metastases. Guidelines recommend performing ultrasound-guided fine-needle aspiration cytology (FNAC) for suspicious nodes to guide management. No specific recommendations are available for the use of FNA thyroglobulin assay (FNA-Tg). This study investigated the diagnostic value of performing FNAC and FNA-Tg.

METHODS

Patient demographics, preoperative investigations, surgery, and lymph node pathology were collected for patients with PTC who underwent lateral neck lymphadenectomy and central compartment reexploration from January 2000 to July 2015. Sensitivities and accuracies were obtained. Patients with both diagnostic studies performed were compared using McNemar's test of paired proportion. Patient, imaging, and lymph node characteristics were correlated with test accuracy.

RESULTS

The 480 patients in this study underwent 706 lateral neck dissections or central compartment reexploration. All the patients underwent preoperative neck ultrasound. Among these patients, FNAC alone was performed before 426 operations (60 %), FNAC with FNA-Tg before 105 operations (15 %), and surgery without biopsy for 175 patients (25 %). The sensitivity, positive predictive value, and accuracy were respectively 96, 95, 100 % for FNAC, 99, 97, and 97 % for FNA-Tg, and 95, 92, and 97 % for FNAC in combination with FNA-Tg. In the subgroup of patients who had both tests performed, the sensitivity of FNA-Tg was superior to that of FNAC (95 vs 87 %; p = 0.04). The addition of FNA-Tg to FNAC increased the detection of metastatic PTC by 13 %.

CONCLUSIONS

For diagnosing cervical lymph node metastases in PTC, FNA-Tg is a valuable adjunct to FNAC. Its use should be considered to avoid missing metastatic disease in patients who may benefit from lymphadenectomy.

Prognosis of patients with benign thyroid nodules: a population-based study

Most thyroid nodules are benign. The ideal follow-up of these patients should reflect their prognosis, which has been scarcely investigated. We aimed to evaluate the prognosis of patients with initial benign thyroid cytology. A population-based study, using the Rochester Epidemiology Project, identifying patients with benign thyroid cytology diagnosed between 2003 and 2006 and completely followed to 2014 using linked medical records. We identified 363 thyroid nodules with benign cytology in 327 patients after fine-needle aspiration biopsy. Patients were on average 53 years old (standard deviation 17), and 80 % were women. The median nodule size was 1.6 cm (interquartile range 1.2-2.4); 26 % had at least one suspicious ultrasound feature. During a median follow-up of 8 years, 54 patients (17 %) with 57 benign nodules underwent thyroidectomy, mostly due to compressive symptoms (44 %). Thyroidectomy was more likely in younger patients [hazard ratio (HR) 0.97, 95 % CI 0.96-0.99] and patients with larger nodules (HR 1.3, 95 % CI 1.16-1.48). Two patients were found to have follicular thyroid cancer in the index nodule (0.6 %) and 6 patients had papillary thyroid cancer detected in other nodules (1.8 %). No patient died from thyroid cancer. Patients with benign thyroid nodules are unlikely to suffer morbidity or mortality due to thyroid cancer. Follow-up strategies for these patients should consider this excellent prognosis and avoid causing unnecessary fear in patients and adding unneeded expense and burden to the healthcare system.

Diagnostic accuracy of ultrasound-guided fine needle aspiration biopsy for thyroid malignancy: systematic review and meta-analysis

PURPOSE

To systematically appraise and summarize the available evidence about the diagnostic accuracy of ultrasound-guided fine needle aspiration biopsy (USFNA) for thyroid malignancy, and to explore the integration of these estimates with the probability of thyroid malignancy before USFNA.

METHODS

A comprehensive search of multiple databases from each database's inception to August 2014 was performed. Eligible studies included those that evaluated patients with thyroid nodules who underwent USFNA and subsequent evaluation by histopathology or long-term follow-up.

RESULTS

We identified 32 studies at moderate risk of bias evaluating the USFNA diagnostic characteristics for the diagnosis of thyroid malignancy. Results were imprecise and inconsistent across trials. The pooled likelihood ratio (LR) of thyroid malignancy for a benign USFNA result was 0.09 (95 % CI 0.06, 0.14; I (2) = 33 %), whereas the pooled LR for a malignant result was 197 (95 % CI, 68, 569; I (2) = 77 %). In the case of a suspicious for follicular neoplasm result, the pooled LR for malignancy was 0.6 (95 % CI, 0.4, 1.0; I (2) = 84 %) and 8.3 (95 % CI, 3.6, 19.2; I (2) = 89) for a result of suspicious for malignancy.

CONCLUSION

The available evidence regarding the diagnostic accuracy of USFNA warrants only limited confidence due to risk of bias, imprecision, and inconsistency. However, some USFNA results (benign, malignant) are likely very helpful, by significantly changing the pre-test probability of thyroid cancer.

Diagnostic accuracy of thyroid nodule growth to predict malignancy in thyroid nodules with benign cytology: systematic review and meta-analysis

BACKGROUND

Thyroid ultrasound to assess for nodular growth is commonly performed during the follow-up of patients with benign thyroid nodules, with the goal of identifying patients with a missed diagnosis of thyroid cancer. The objective of this study was to summarize the evidence regarding the diagnostic accuracy of growth during follow-up of benign thyroid nodules for thyroid cancer.

METHODS

We searched multiple electronic databases using a search strategy designed by an experienced medical librarian from inception to March 2015. Eligible studies included patients with benign thyroid nodules assessed for growth during follow-up and evaluated for thyroid cancer either by surgical histology or a repeat fine needle aspiration biopsy. Reviewers working independently and in duplicate recorded data and assessed each study.

RESULTS

The seven eligible studies lacked safeguards against bias and generated results that were imprecise with wide confidence intervals and inconsistent across studies. This warrants very low confidence in these results. The odds of nodule growth in patients with thyroid cancer on histopathology over these odds in patients without thyroid cancer (diagnostic odds ratio) was 0·58 (95% CI: 0·26-1·3); the diagnostic odds ratio was 2·2 (95% CI: 0·26-18) when an abnormal repeat biopsy was the reference standard.

CONCLUSION

The body of evidence linking nodule growth with thyroid cancer during the follow-up of benign nodules warrants very low confidence. In the era of high-value health care, the commonplace practice of following benign thyroid nodules with serial ultrasound assessment of growth to diagnose cancer can be questioned, calling for imminent evaluation.

Statin Use, Diabetes Incidence and Overall Mortality in Normoglycemic and Impaired Fasting Glucose Patients

BACKGROUND

The association between the use of statins and the risk of diabetes and increased mortality within the same population has been a source of controversy, and may underestimate the value of statins for patients at risk.

OBJECTIVE

We aimed to assess whether statin use increases the risk of developing diabetes or affects overall mortality among normoglycemic patients and patients with impaired fasting glucose (IFG).

DESIGN AND PARTICIPANTS

Observational cohort study of 13,508 normoglycemic patients (n = 4460; 33% taking statins) and 4563 IFG patients (n = 1865; 41% taking statin) among residents of Olmsted County, Minnesota, with clinical data in the Mayo Clinic electronic medical record and at least one outpatient fasting glucose test between 1999 and 2004. Demographics, vital signs, tobacco use, laboratory results, medications and comorbidities were obtained by electronic search for the period 1999-2004. Results were analyzed by Cox proportional hazards models, and the risk of incident diabetes and mortality were analyzed by survival curves using the Kaplan-Meier method.

MAIN MEASURES

The main endpoints were new clinical diagnosis of diabetes mellitus and total mortality.

KEY RESULTS

After a mean of 6 years of follow-up, statin use was found to be associated with an increased risk of incident diabetes in the normoglycemic (HR 1.19; 95% CI, 1.05 to 1.35; p = 0.007) and IFG groups (HR 1.24; 95%CI, 1.11 to 1.38; p = 0.0001). At the same time, overall mortality decreased in both normoglycemic (HR 0.70; 95% CI, 0.66 to 0.80; p < 0.0001) and IFG patients (HR 0.77, 95% CI, 0.64 to 0.91; p = 0.0029) with statin use.

CONCLUSION

In general, recommendations for statin use should not be affected by concerns over an increased risk of developing diabetes, since the benefit of reduced mortality clearly outweighs this small (19-24%) risk.

Type 2 Diabetes Mellitus Trajectories and Associated Risks

Disease progression models, statistical models that assess a patient's risk of diabetes progression, are popular tools in clinical practice for prevention and management of chronic conditions. Most, if not all, models currently in use are based on gold standard clinical trial data. The relatively small sample size available from clinical trial limits these models only considering the patient's state at the time of the assessment and ignoring the trajectory, the sequence of events, that led up to the state. Recent advances in the adoption of electronic health record (EHR) systems and the large sample size they contain have paved the way to build disease progression models that can take trajectories into account, leading to increasingly accurate and personalized assessment. To address these problems, we present a novel method to observe trajectories directly. We demonstrate the effectiveness of the proposed method by studying type 2 diabetes mellitus (T2DM) trajectories. Specifically, using EHR data for a large population-based cohort, we identified a typical trajectory that most people follow, which is a sequence of diseases from hyperlipidemia (HLD) to hypertension (HTN), impaired fasting glucose (IFG), and T2DM. In addition, we also show that patients who follow different trajectories can face significantly increased or decreased risk.

The Value of Repeat Thyroid Fine-Needle Aspiration Biopsy in Patients with a Previously Benign Result: How Often Does It Alter Management?

BACKGROUND

Thyroid nodules are prevalent and mostly benign, being present in up to 67% of the population when assessed by ultrasound. Due to the variable diagnostic performance of ultrasound-guided fine-needle aspiration biopsy (USFNA) of the thyroid and the possibility of a false-negative result, current clinical guidelines recommend ultrasonographic follow-up of benign thyroid nodules. The objective of this study was to evaluate the clinical relevance of a repeat fine-needle aspiration (rFNA) in patients with an initial benign fine-needle aspiration biopsy (iFNA).

METHODS

A retrospective review was conducted of medical records of patients seen at the Mayo Clinic between January of 2003 and December of 2013 who had undergone rFNA of a nodule with benign iFNA. The outcome measured was the result of the rFNA and histopathological correlation, when available.

RESULTS

Three hundred and thirty-four nodules with benign iFNA underwent rFNA during the 10-year study period. The rFNA was most commonly reported as benign (85.3%), followed by suspicious (7.2%), nondiagnostic (5.7%), and malignant (1.8%). The rFNA changed clinical management in 9.5% of the cases. The prevalence of thyroid malignancy ranged from 4.1% to 1.2% based on the gold standard used (histology vs. long-term follow-up, 4.0 ± 2.3 years).

CONCLUSION

In the majority of patients with a benign iFNA, results of the rFNA were unchanged. However, in a small group of patients, the rFNA may differ from the initial results, and alter management. Even so, the prevalence of malignancy remains very low, ranging from 1.2% to 4.1% depending on the gold standard.

Thyroglobulin (Tg) Testing Revisited: Tg Assays, TgAb Assays, and Correlation of Results With Clinical Outcomes

CONTEXT

Measurement of thyroglobulin (Tg) by mass spectrometry (Tg-MS) is emerging as a tool for accurate Tg quantification in patients with anti-Tg autoantibodies (TgAbs).

OBJECTIVE

The objective of the study was to perform analytical and clinical evaluations of two Tg-MS assays in comparison with immunometric Tg assays (Tg-IAs) and Tg RIAs (Tg-RIAs) in a cohort of thyroid cancer patients.

METHODS

A total of 589 samples from 495 patients, 243 TgAb-/252 TgAb+, were tested by Beckman, Roche, Siemens-Immulite, and Thermo-Brahms Tg and TgAb assays, two Tg-RIAs, and two Tg-MS assays.

RESULTS

The frequency of TgAb+ was 58%, 41%, 27%, and 39% for Roche, Beckman, Siemens-Immulite, and Thermo-Brahms, respectively. In TgAb- samples, clinical sensitivities and specificities of 100% and 74%-100%, respectively, were observed across all assays. In TgAb+ samples, all Tg-IAs demonstrated assay-dependent Tg underestimation, ranging from 41% to 86%. In TgAb+ samples, the use of a common cutoff (0.5 ng/mL) for the Tg-MS, three Tg-IAs, and the USC-RIA improved the sensitivity for the Tg-MSs and Tg-RIAs when compared with the Tg-IAs. In up to 20% of TgAb+ cases, Tg-IAs failed to detect Tg that was detectable by Tg-MS. In Tg-RIAs false-high biases were observed in TgAb+ samples containing low Tg concentrations.

CONCLUSIONS

Tg-IAs remain the method of choice for Tg quantitation in TgAb- patients. In TgAb+ patients with undetectable Tg by immunometric assay, the Tg-MS will detect Tg in up to 20% additional cases. The Tg-RIA will detect Tg in approximately 35% cases, but a significant proportion of these will be clinical false-positive results. The undetectable Tg-MS seen in approximately 40% of TgAb+ cases in patients with disease need further evaluation.

Survey of current approaches to non-diagnostic fine-needle aspiration from solid thyroid nodules

The exact frequency of non-diagnostic ultrasound-guided fine-needle aspiration (USFNA) is unknown. Clinical guidelines suggest repeating USFNA of these nodules. However, there is no specific recommendation or evidence on how and when this re-aspiration should be done. We aim to describe the approaches considered by endocrinologists to yield the highest likelihood of a satisfactory sample in solid thyroid nodules. A cross-sectional survey of The Endocrine Society (TES) and the American Thyroid Association members was conducted between October and December 2012. A total of 694 surveys were returned, 648 (93.4 %) from TES. The responders were equally divided between private and academic settings and had a high degree of expertise. Thirty-nine percent of respondents estimated the frequency of non-diagnostic USFNA to be above 10 %. For its management, 311 (46 %) recommended repeating USFNA in 1-3 months. For a second non-diagnostic USFNA, 216 (31 %) recommend surgery. The most common approaches to increase the diagnostic yield were (1) use of suction with USFNA, 18 % and (2) changing the targeted area of biopsy within the nodule, 18 %. Few considered the patients' preferences as an important driver for the management of non-diagnostic USFNA. Finally, a molecular test for bypassing non-diagnostic USFNA was regarded as the most needed strategy for future research. Variability exists in the management of non-diagnostic USFNA and strategies to increase the diagnostic yield. Testing the suggested strategies in clinical trials and understanding patient's preferences should be supported by guideline panels and funding agencies.

Divisive Hierarchical Clustering towards Identifying Clinically Significant Pre-Diabetes Subpopulations

Type 2 Diabetes Mellitus is a progressive disease with increased risk of developing serious complications. Identifying subpopulations and their relevant risk factors can contribute to the prevention and effective management of diabetes. We use a novel divisive hierarchical clustering technique to identify clinically interesting subpopulations in a large cohort of Olmsted County, MN residents. Our results show that our clustering algorithm successfully identified clinically interesting clusters consisting of patients with higher or lower risk of diabetes than the general population. The proposed algorithm offers fine control over the granularity of the clustering, has the ability to seamlessly discover and incorporate interactions among the risk factors, and can handle non-proportional hazards, as well. It has the potential to significantly impact clinical practice by recognizing patients with specific risk factors who may benefit from an alternative management approach potentially leading to the prevention of diabetes and its complications.

An independent study of a gene expression classifier (Afirma) in the evaluation of cytologically indeterminate thyroid nodules

CONTEXT

Molecular markers hold the promise of improved diagnostic yield in thyroid fine-needle biopsy. The Afirma gene expression classifier (GEC), available commercially, reports a negative predictive value of 94% in the diagnosis of benign nodules after indeterminate cytology. However, there are currently no independent studies of the performance of this assay.

OBJECTIVE

The aim was to assess the performance of the Afirma GEC in an academic medical center.

DESIGN

Samples for the GEC were collected according to the manufacturer's recommended protocol from patients undergoing thyroid fine-needle aspiration. We requested GEC analysis on nodules reported cytologically as follicular neoplasm or atypia or follicular lesion of undetermined significance from patients willing to defer surgery.

PATIENTS

All patients undergoing thyroid fine-needle aspiration during the study period, whose cytology was reported as follicular neoplasm or atypia of undetermined significance/follicular lesion of undetermined significance, were offered access to the test and recruited to this study.

INTERVENTION

PATIENTS whose GEC was "benign" were offered ultrasound follow-up in lieu of surgery. Those with a "suspicious" GEC were advised to undergo diagnostic lobectomy.

SETTING

The study was conducted at a large academic medical center.

MAIN OUTCOME MEASURE

We measured the rate of benign and suspicious calls from the Afirma GEC and histological diagnosis after surgery.

RESULTS

A total of 72 nucleic acid samples were sent for GEC analysis. In 12 (17%) of these samples, there was insufficient mRNA, leaving 60 Afirma results for analysis. Of these, 16 (27%) were benign, whereas 44 (73%) were suspicious. The rate of confirmed malignancy in GEC-suspicious nodules was only 17%.

CONCLUSION

The Afirma GEC demonstrates a lower than expected rate of benign reports in follicular or Hürthle cell neoplasm and a lower than anticipated malignancy rate within GEC-suspicious nodules. These data suggest that the positive predictive value of the GEC is lower than previously reported and call into question the performance of the test when applied in the context of specialized academic cytopathology.

Multiple endocrine neoplasia type 2A due to an exon 8 (G533C) mutation in a large North American kindred

BACKGROUND

Medullary thyroid cancer, although most commonly sporadic, may be part of the multiple endocrine neoplasia type 2 (MEN2) syndromes, generally due to mutations in the RET proto-oncogene. The majority of these mutations are located in exons 10, 11, and 13-16. More rarely, mutations in other exons have been described. We report for the first time a family from the United States with a rare mutation involving exon 8 of the RET proto-oncogene, corresponding to a p.Gly533Cys substitution (G533C) leading to the development of MEN2A syndrome in several affected family members. This mutation had only been previously described in a large family in Brazil and in 7.75% of patients with apparently sporadic medullary thyroid cancer (MTC) in Greece.

METHODS

Given a strong index of suspicion, a genetic analysis to evaluate for uncommon mutations in the RET proto-oncogene identified the presence of the G533C missense mutation, despite initial negative screening for common mutations. We describe a family with a total of 47 individuals from five generations with multiple members affected with this mutation.

RESULTS

Our data suggest that in patients with this mutation, pheochromocytoma is more common than previously reported, and that in some cases this mutation may be associated with a more aggressive phenotype than initially described.

CONCLUSIONS

MEN2A due to the G533C mutation in exon 8 may be more common and more aggressive than previously recognized. In patients with medullary thyroid cancer with negative screening for common mutations in the RET oncogene but a strong index of suspicion, DNA sequence analysis of less commonly involved exons should be considered.

Quantifying the effect of statin use in pre-diabetic phenotypes discovered through association rule mining

Prediabetes is the most important risk factor for developing type-2 diabetes mellitus, an important and growing epidemic. Prediabetes is often associated with comorbidities including hypercholesterolemia. While statin drugs are indicated to treat hypercholesterolemia, recent reports suggest a possible increased risk of developing overt diabetes associated with the use of statins. Association rule mining is a data mining technique capable of identifying interesting relationships between risks and treatments. However, it is limited in its ability to accurately calculate the effect of a treatment, as it does not appropriately account for bias and confounding. We propose a novel combination of propensity score matching and association rule mining to account for this bias, and find meaningful associations between a treatment and outcome for various subpopulations. We demonstrate this technique on a real diabetes data set examining the relationship between statin use and diabetes, and identify risk and protective factors previously not clearly defined.