Risk Factors for Thyroid Dysfunction in Pregnancy: An Individual Participant Data Meta-Analysis

Background: International guidelines recommend targeted screening to identify gestational thyroid dysfunction. However, currently used risk factors have questionable discriminative ability. We quantified the risk for thyroid function test abnormalities for a subset of risk factors currently used in international guidelines. Methods: We included prospective cohort studies with data on gestational maternal thyroid function and potential risk factors (maternal age, body mass index [BMI], parity, smoking status, pregnancy through in vitro fertilization, twin pregnancy, gestational age, maternal education, and thyroid peroxidase antibody [TPOAb] or thyroglobulin antibody [TgAb] positivity). Exclusion criteria were pre-existing thyroid disease and use of thyroid interfering medication. We analyzed individual participant data using mixed-effects regression models. Primary outcomes were overt and subclinical hypothyroidism and a treatment indication (defined as overt hypothyroidism, subclinical hypothyroidism with thyrotropin >10 mU/L, or subclinical hypothyroidism with TPOAb positivity). Results: The study population comprised 65,559 participants in 25 cohorts. The screening rate in cohorts using risk factors currently recommended (age >30 years, parity ≥2, BMI ≥40) was 58%, with a detection rate for overt and subclinical hypothyroidism of 59%. The absolute risk for overt or subclinical hypothyroidism varied <2% over the full range of age and BMI and for any parity. Receiver operating characteristic curves, fitted using maternal age, BMI, smoking status, parity, and gestational age at blood sampling as explanatory variables, yielded areas under the curve ranging from 0.58 to 0.63 for the primary outcomes. TPOAbs/TgAbs positivity was associated with overt hypothyroidism (approximate risk for antibody negativity 0.1%, isolated TgAb positivity 2.4%, isolated TPOAb positivity 3.8%, combined antibody positivity 7.0%; p < 0.001), subclinical hypothyroidism (risk for antibody negativity 2.2%, isolated TgAb positivity 8.1%, isolated TPOAb positivity 14.2%, combined antibody positivity 20.0%; p < 0.001) and a treatment indication (risk for antibody negativity 0.2%, isolated TgAb positivity 2.2%, isolated TPOAb positivity 3.0%, and combined antibody positivity 5.1%; p < 0.001). Twin pregnancy was associated with a higher risk of overt hyperthyroidism (5.6% vs. 0.7%; p < 0.001). Conclusions: The risk factors assessed in this study had poor predictive ability for detecting thyroid function test abnormalities, questioning their clinical usability for targeted screening. As expected, TPOAb positivity (used as a benchmark) was a relevant risk factor for (subclinical) hypothyroidism. These results provide insights into different risk factors for gestational thyroid dysfunction.

Association of Gestational Free and Total Triiodothyronine With Gestational Hypertension, Preeclampsia, Preterm Birth, and Birth Weight: An Individual Participant Data Meta-analysis

CONTEXT

Triiodothyronine (T3) is the bioactive form of thyroid hormone. In contrast to thyroid-stimulating hormone and free thyroxine, we lack knowledge on the association of gestational T3 with adverse obstetric outcomes.

OBJECTIVE

To investigate the associaiton of gestational free or total T3 (FT3 or TT3) with adverse obstetric outcomes.

METHODS

We collected individual participant data from prospective cohort studies on gestational FT3 or TT3, adverse obstetric outcomes (preeclampsia, gestational hypertension, preterm birth and very preterm birth, small for gestational age [SGA], and large for gestational age [LGA]), and potential confounders. We used mixed-effects regression models adjusting for potential confounders.

RESULTS

The final study population comprised 33 118 mother-child pairs of which 27 331 had data on FT3 and 16 164 on TT3. There was a U-shaped association of FT3 with preeclampsia (P = .0069) and a J-shaped association with the risk of gestational hypertension (P = .029). Higher TT3 was associated with a higher risk of gestational hypertension (OR per SD of TT3 1.20, 95% CI 1.08 to 1.33; P = .0007). A lower TT3 but not FT3 was associated with a higher risk of very preterm birth (OR 0.72, 95% CI 0.55 to 0.94; P = .018). TT3 but not FT3 was positively associated with birth weight (mean difference per 1 SD increase in TT3 12.8, 95% CI 6.5 to 19.1 g, P < .0001) but there was no association with SGA or LGA.

CONCLUSION

This study provides new insights on the association of gestational FT3 and TT3 with major adverse pregnancy outcomes that form the basis for future studies required to elucidate the effects of thyroid function on pregnancy outcomes. Based on the current study, routine FT3 or TT3 measurements for the assessment of thyroid function during pregnancy do not seem to be of added value in the risk assessment for adverse outcomes.

Non-Operative, Active Surveillance of Larger Malignant and Suspicious Thyroid Nodules

CONTEXT

Active surveillance for papillary thyroid cancer (PTC) meeting criteria for surgical resection is uncommon. Which patients may prove reasonable candidates for this approach is not well defined.

OBJECTIVE

To examine the feasibility and safety of active surveillance for patients with known or suspected intrathyroidal PTC up to 4cm in diameter.

DESIGN, SETTING, AND PARTICIPANTS

Retrospective review of all consecutive patients who underwent non-operative active surveillance of suspicious or malignant thyroid nodules over a 20-year period from 2001-2021. We included patients with an initial US-FNA confirming either: a) Bethesda 5 or 6 cytology or, b) a "suspicious" AFIRMA molecular test. The primary outcomes and measures included the rate of adverse oncologic outcomes (mortality and recurrence), as well as the cumulative incidence of size/volume growth.

RESULTS

Sixty-nine patients were followed with active surveillance for 1 year or longer (average 55 months), with 26 patients (38%) having nodules ≥ 2 cm. No patients were found to develop new incident occurrence of lymph node or distant metastasis. One patient however, demonstrated concern for progression to a dedifferentiated cancer on repeat core biopsy 17 years after initial start non-operative selection. 21% of patients had an increase in maximum diameter more than 3 mm, and volume increase ≥50% was noted in 25% of patients. Thirteen patients ultimately underwent delayed (rescue) surgery, and no disease recurrence was noted after such treatment. Age and initial nodule size were not predictors of nodule growth.

CONCLUSIONS

These data expand consideration of active surveillance of papillary thyroid carcinoma in select patients with intrathyroidal suspected malignancy >1cm in diameter. Rescue surgery, if required at a later timepoint, appears effective.

Vitamin D and Marine n-3 Fatty Acids for Autoimmune Disease Prevention: Outcomes Two Years After Completion of a Double-Blind, Placebo-Controlled Trial

OBJECTIVE

In the 5.3-year randomized, 2 × 2 factorial, double-blind, placebo-controlled Vitamin D and Omega-3 Trial (VITAL), vitamin D supplementation reduced autoimmune disease (AD) incidence (hazard ratio [HR] 0.78, 95% confidence interval [CI] 0.61-0.99). Omega-3 (n-3) fatty acid supplementation showed a statistically nonsignificant reduction (HR 0.85, 95% CI 0.67-1.08). We aimed to confirm further AD cases arising during and after randomization and assess sustained effects with two years of postintervention observation.

METHODS

Of the 12,786 men aged ≥50 and 13,085 women aged ≥55 initially randomized, we observed surviving and willing participants for two more years. We continued to confirm annual participant-reported new AD by medical record review. Cox models calculated HRs for all confirmed incident AD, (and secondary endpoints, including probable cases, and individual ADs), during the observational and randomized periods.

RESULTS

A total of 21,592 participants (83.5%) were observed for two more years; 514 participants developed incident confirmed AD (236 since prior report), of whom 255 had been randomized to vitamin D versus 259 to vitamin D placebo (HR 0.98 [95% CI 0.83-1.17] at 7 years). AD was confirmed in 234 participants initially randomized to n-3 fatty acids versus 280 randomized to its placebo (HR 0.83 [95% CI 0.70-0.99] at 7 years). Of newly confirmed cases, 65 had onset during randomization; their inclusion changed randomized results as follows: HR 0.85 (95% CI 0.70-1.04) for vitamin D and HR 0.87 (95% CI 0.71-1.06) for n-3 fatty acids.

CONCLUSION

Two years after trial termination, the protective effects of 2000 IU/day of vitamin D dissipated, but 1,000 mg/day of n-3 fatty acids had a sustained effect in reducing AD incidence.

Navigating the acute to post-acute transition with patients: a first characterization of medical student knowledge gaps in rehabilitation and post-acute care

PURPOSE

Clinical rehabilitation and post-acute care (PAC) learning experiences are not uniformly required within medical school core curricula in the United States or internationally. This study aims to characterize what medical students might know/need to know to support patients in the transition from acute hospitalization to post-acute rehabilitation settings.

MATERIALS/METHODS

The medical student cohort completing required clinical rotations in a United States quaternary care hospital system was provided a voluntary survey prompting reflection on experiences discharging patients to rehabilitation/PAC and related learning needs. Data were analyzed using descriptive statistics and qualitative grounded theory.

RESULTS

Response rate was 72% (39/54). All respondents reported at least one gap in rehabilitation/PAC knowledge, falling into 8 themes: daily experience of rehabilitation/PAC; determination of eligibility/screening processes; distinctions among levels of rehabilitation/PAC; insurance coverage/equity; rehabilitation/PAC clinical practice environment; post-rehabilitation/PAC discharge support; medical capabilities within PAC settings; developing rehabilitation goals.

CONCLUSIONS

Despite caring for patients discharged to post-acute rehabilitation settings, medical students lack essential knowledge about the process of rehabilitation and recovery, including patient eligibility for and service availability across PAC settings. Explicit rehabilitation/PAC education for medical students could enhance their ability to counsel and advocate for patients with disability and rehabilitation needs through care transitions.Implications for rehabilitationMedical students lack knowledge about rehabilitation and post-acute care that is important for helping patients navigate the acute to post-acute transition.Dedicated rehabilitation/post-acute care education could prepare trainees for counseling and advocating for patients during care transitions.Knowledge gaps identified in this study could inform development of curricular interventions to address medical student learning needs.

Additional Oncogenic Alterations in RAS-Driven Differentiated Thyroid Cancers Associate with Worse Clinicopathologic Outcomes

PURPOSE

RAS mutations occur across the spectrum of thyroid neoplasms, and more tools are needed for better prognostication. The objective of this study was to evaluate how additional genetic events affecting key genes modify prognosis in patients with RAS-mutant thyroid cancers, and specifically differentiated thyroid cancers (DTC).

EXPERIMENTAL DESIGN

We performed a clinical-genomic analysis of consecutive patients with DTC, poorly differentiated (PDTC), or anaplastic thyroid cancer (ATC) between January 2014 and December 2021, in whom a custom-targeted next-generation sequencing assay was performed. Patients harboring RAS mutations were included, and we compared their clinical features and outcomes based upon the presence of additional oncogenic alterations.

RESULTS

Seventy-eight patients were identified, with 22% (17/78) harboring a driver RAS mutation plus an additional oncogenic alteration. All six (100%) ATCs had an additional mutation. Compared with DTCs harboring a solitary RAS mutation, patients with DTC with RAS and additional mutation(s) were more likely to be classified as American Thyroid Association high-risk of recurrence (77% vs. 12%; P < 0.001) and to have larger primary tumors (4.7 vs. 2.5 cm; P = 0.002) and advanced stage (III or IV) at presentation (67% vs. 3%; P < 0.001). Importantly, over an average 65-month follow-up, DTC-specific-mortality was more than 10-fold higher (20% vs. 1.8%; P = 0.011) when additional mutations were identified.

CONCLUSIONS

Identification of key additional mutations in patients with RAS-mutant thyroid cancers confers a more aggressive phenotype, increases mortality risk in DTC, and can explain the diversity of RAS-mutated thyroid neoplasia. These data support genomic profiling of DTCs to inform prognosis and clinical decision-making.

Identifying and Predicting Diverse Patterns of Benign Nodule Growth

CONTEXT

The natural history of benign thyroid nodules is typically characterized by slow growth and minimal risk of malignant transformation. Available data have, to date, been unable to elucidate the diversity of benign nodule growth patterns over time nor predictive of which patients follow which pattern.

OBJECTIVE

We aimed to better define the diverse patterns of benign nodule behavior and their predictors.

METHODS

We prospectively studied 389 consecutive patients with solitary, solid, cytologically benign thyroid nodules ≥1 cm and follow-up ultrasound for at least 4 years. Demographic, sonographic, biochemical data were collected at initial evaluation, and subsequent growth patterns were identified over the follow-up. Predictors of growth at initial evaluation and 3 years of follow-up were defined.

RESULTS

The mean (±SD) follow-up was 7.7 (±2.7) years. Three distinct growth patterns were identified: A) stagnant nodules with average growth rate < 0.2 mm/year; B) slow-growing nodules with a rate 0.2 to 1.0 mm/year; and C) fast-growing nodules increasing > 1.0 mm/year. Fast-growing nodules represented 17.2% of the cohort, and were more frequent in patients younger than 50 years (OR 2.2 [1.2-4.1], P = 0.016), and in larger nodules (2.0-2.9 cm, OR 3.5 [1.7-7.1], P = 0.001; >3.0 cm, OR 4.4 [1.8-10.4], P = 0.001 vs reference 1-1.9 cm). In a multiple regression model, nodule growth at 3 years at an average growth rate over 0.2 mm/year over 3 years since initial evaluation was an independent predictor of longer-term fast nodule growth, even after adjusting for age, biological sex, TSH level, and nodule size (P < 0.001).

CONCLUSION

The natural history of benign nodule growth is diverse, with over 80% of nodules demonstrating minimal to no growth long-term. Nearly 20% of cytologically benign nodules may exhibit a fast, continued growth pattern, which can be predicted by the 3-year growth rate pattern. These findings can help inform decision making for tailored benign nodule follow-up and monitoring.

Deep learning to predict cervical lymph node metastasis from intraoperative frozen section of tumour in papillary thyroid carcinoma: a multicentre diagnostic study

Background

Lymph node metastasis (LNM) assessment in patients with papillary thyroid carcinoma (PTC) is of great value. This study aimed to develop a deep learning model applied to intraoperative frozen section for prediction of LNM in PTC patients.

Methods

We established a deep-learning model (ThyNet-LNM) with the multiple-instance learning framework to predict LNM using whole slide images (WSIs) from intraoperative frozen sections of PTC. Data for the development and validation of ThyNet-LNM were retrospectively derived from four hospitals from January 2018 to December 2021. The ThyNet-LNM was trained using 1987 WSIs from 1120 patients obtained at the First Affiliated Hospital of Sun Yat-sen University. The ThyNet-LNM was then validated in the independent internal test set (479 WSIs from 280 patients) as well as three external test sets (1335 WSIs from 692 patients). The performance of ThyNet-LNM was further compared with preoperative ultrasound and computed tomography (CT).

Findings

The area under the receiver operating characteristic curves (AUCs) of ThyNet-LNM were 0.80 (95% CI 0.74-0.84), 0.81 (95% CI 0.77-0.86), 0.76 (95% CI 0.68-0.83), and 0.81 (95% CI 0.75-0.85) in internal test set and three external test sets, respectively. The AUCs of ThyNet-LNM were significantly higher than those of ultrasound and CT or their combination in all four test sets (all P < 0.01). Of 397 clinically node-negative (cN0) patients, the rate of unnecessary lymph node dissection decreased from 56.4% to 14.9% by ThyNet-LNM.

Interpretation

The ThyNet-LNM showed promising efficacy as a potential novel method in evaluating intraoperative LNM status, providing real-time guidance for decision. Furthermore, this led to a reduction of unnecessary lymph node dissection in cN0 patients.

Funding

National Natural Science Foundation of China, Guangzhou Science and Technology Project, and Guangxi Medical High-level Key Talents Training "139" Program.

Papillary Thyroid Carcinomas with Tall Cell Features: An Intermediate Entity between Classic and Tall Cell Subtypes

BACKGROUND While the diagnosis of papillary thyroid carcinomas with tall cell features (PTCtcf) is often made for carcinomas with histologic features intermediate between classic and tall cell subtypes of PTC (tcPTC), its comparative signature to that of either tcPTC or classic PTC is less clear. The objective of this study was to perform an integrative clinicopathologic and genomic analysis elucidating the spectrum of tcPTC, PTCtcf and classic PTC. METHODS We analyzed all consecutive patients with tcPTC and PTCtcf evaluated at a tertiary academic referral center between 2005-2020, as well as a comparative cohort of classic PTC, in a retrospective observational cohort analysis. Clinicopathological data were compared among the three groups, including progression-free survival (PFS), recurrent/persistent disease, and a negative composite outcome of death, progression, or need for advanced therapy. To specifically understand differences between tcPTC and PTCtcf, targeted next-generation sequencing (NGS) was performed in a subset of these cohorts. RESULTS A total of 292 patients were analyzed (81 tcPTC, 65 PTCtcf, 146 classic PTC). Thirteen percent tcPTC vs. 8% PTCtcf vs. 1% classic PTC had advanced AJCC stage (p=0.002). Similarly, macroscopic extrathyroidal extension was observed in 38% of tcPTC, 14% of PTCtcf and 12% of classic PTC (p<0.001). The 5-year PFS was 76.5%, 81.5% and 88.3% for tcPTC, PTCtcf and classic PTC, respectively, while the rates of the negative composite outcome 40.2% for tcPTC, 20.7% for PTCtcf and 11.2% for classic PTC (p<0.001). In a multivariable Cox regression analysis, the negative composite outcome was independently associated with tcPTC [HR 4.3 95% CI (1.1-16.1), p=0.03]. tcPTC demonstrated substantially more hotspot TERT promoter mutations than PTCtcf (44% vs. 6%, p=0.012). CONCLUSIONS Our study demonstrates a continuum of disease-specific risk of PTC, pointing at PTCtcf as an intermediate entity between tcPTC and classic PTC. These data provide a more refined understanding of risk at time of presentation, while better elucidating the diversity of genomic drivers.

Active Surveillance for Low-Risk Differentiated Thyroid Cancer

Less aggressive treatment options, including hemithyroidectomy and active surveillance, have been accepted as treatment options for low-risk small, differentiated thyroid carcinoma (DTC). Multiple studies have shown a low rate of cancer growth and lymph node metastases and no evidence of distant metastases during active surveillance of low-risk small DTC. However, not all patients with low -risk small DTC are ideal or appropriate candidate for active surveillance. Patients with thyroid cancer adjacent to either the trachea or recurrent laryngeal nerve or those with evidence of extrathyroidal extension, a high-risk molecular profile, lymph node, or distant metastases are considered inappropriate candidates for active surveillance. In addition, there are other essential factors that clinicians should consider while recommending active surveillance, including patient financial and insurance status; availability of high-quality neck ultrasounds and experienced radiologists, endocrinologists, and surgeons; and patient preference, level of anxiety, and willingness to undergo prolonged surveillance and follow-up imaging.

Engaging Health Professions Educators in an Initiative to Create and Disseminate Micro Virtual Asynchronous Educator Development Content During COVID-19

OBJECTIVES

Most teaching activities pivoted to virtual during COVID-19. Demanding schedules necessitated brief, asynchronous, and widely disseminated professional development to encourage connection and reinforce educator identity. We created and disseminated micro virtual asynchronous educator development while engaging educators from interprofessional backgrounds to co-create teaching tips. We undertook educational evaluation to understand the impact of our educational initiative, measured along 2 professional development dimensions offering contexts for learning-the individual or independent experience, and the group or collective experience-which served as an organizing framework from which to interpret our results.

METHODS

Between June 2020 and July 2021, 74 educators at our institution were asked to participate in our "One Minute Teaching Tips" initiative by providing a brief tip or pearl. Each tip was edited, prepared as a high-quality infographic, and shared via: (1) website; (2) digital monitors; (3) newsletter; and (4) Twitter (now X). Quantitative metrics measuring website and Twitter engagement were analyzed descriptively and to determine distinctions among key variables. Participants answered a brief survey and directed content analysis was utilized to analyze the open-ended responses.

RESULTS

Fifty educators (67.5%) participated. Among those, 45 (90%) completed the survey. Tips were accessed via website 1447 times, averaging 28.9/week. The average tweet garnered 43.2 engagements. Six categories aligned with the individual dimension: participants engaged meaningfully, considered prior experience, relied on educational principles, focused on interest or passion, reflected on teaching practices, and experienced reinforced professional identity. Six categories aligned with the collective dimension: participants felt the initiative supported institutional need, was visible to the community, encouraged engagement with other tips, supported inclusive participation, brought value within the community, and showcased education.

CONCLUSION

Our initiative aligns with a contemporary understanding of professional development and was impactful along individual and collective dimensions. Similar initiatives could be developed in alignment with accreditation requirements.

TSH and FT4 Reference Intervals in Pregnancy: A Systematic Review and Individual Participant Data Meta-Analysis

CONTEXT

Interpretation of thyroid function tests during pregnancy is limited by the generalizability of reference intervals between cohorts due to inconsistent methodology.

OBJECTIVE

(1) To provide an overview of published reference intervals for thyrotropin (TSH) and free thyroxine (FT4) in pregnancy, (2) to assess the consequences of common methodological between-study differences by combining raw data from different cohorts.

METHODS

(1) Ovid MEDLINE, EMBASE, and Web of Science were searched until December 12, 2021. Studies were assessed in duplicate. (2) The individual participant data (IPD) meta-analysis was performed in participating cohorts in the Consortium on Thyroid and Pregnancy.

RESULTS

(1) Large between-study methodological differences were identified, 11 of 102 included studies were in accordance with current guidelines; (2) 22 cohorts involving 63 198 participants were included in the meta-analysis. Not excluding thyroid peroxidase antibody-positive participants led to a rise in the upper limits of TSH in all cohorts, especially in the first (mean +17.4%; range +1.6 to +30.3%) and second trimester (mean +9.8%; range +0.6 to +32.3%). The use of the 95th percentile led to considerable changes in upper limits, varying from -10.8% to -21.8% for TSH and -1.2% to -13.2% for FT4. All other additional exclusion criteria changed reference interval cut-offs by a maximum of 3.5%. Applying these findings to the 102 studies included in the systematic review, 48 studies could be used in a clinical setting.

CONCLUSION

We provide an overview of clinically relevant reference intervals for TSH and FT4 in pregnancy. The results of the meta-analysis indicate that future studies can adopt a simplified study setup without additional exclusion criteria.

Association of Thyroid Peroxidase Antibodies and Thyroglobulin Antibodies with Thyroid Function in Pregnancy: An Individual Participant Data Meta-Analysis

Objectives: Thyroid autoimmunity is common in pregnant women and associated with thyroid dysfunction and adverse obstetric outcomes. Most studies focus on thyroid peroxidase antibodies (TPOAbs) assessed by a negative-positive dichotomy and rarely take into account thyroglobulin antibodies (TgAbs). This study aimed at determining the association of TPOAbs and TgAbs, respectively, and interdependently, with maternal thyroid function. Methods: This was a meta-analysis of individual participant cross-sectional data from 20 cohorts in the Consortium on Thyroid and Pregnancy. Women with multiple pregnancy, pregnancy by assisted reproductive technology, history of thyroid disease, or use of thyroid interfering medication were excluded. Associations of (log2) TPOAbs and TgAbs (with/without mutual adjustment) with cohort-specific z-scores of (log2) thyrotropin (TSH), free triiodothyronine (fT3), total triiodothyronine (TT3), free thyroxine (fT4), total thyroxine (TT4), or triiodothyronine:thyroxine (T3:T4) ratio were evaluated in a linear mixed model. Results: In total, 51,138 women participated (51,094 had TPOAb-data and 27,874 had TgAb-data). Isolated TPOAb positivity was present in 4.1% [95% confidence interval, CI: 3.0 to 5.2], isolated TgAb positivity in 4.8% [CI: 2.9 to 6.6], and positivity for both antibodies in 4.7% [CI: 3.1 to 6.3]. Compared with antibody-negative women, TSH was higher in women with isolated TPOAb positivity (z-score increment 0.40, CI: 0.16 to 0.64) and TgAb positivity (0.21, CI: 0.10 to 0.32), but highest in those positive for both antibodies (0.54, CI: 0.36 to 0.71). There was a dose-response effect of higher TPOAb and TgAb concentrations with higher TSH (TSH z-score increment for TPOAbs 0.12, CI: 0.09 to 0.15, TgAbs 0.08, CI: 0.02 to 0.15). When adjusting analyses for the other antibody, only the association of TPOAbs remained statistically significant. A higher TPOAb concentration was associated with lower fT4 (p < 0.001) and higher T3:T4 ratio (0.09, CI: 0.03 to 0.14), however, the association with fT4 was not significant when adjusting for TgAbs (p = 0.16). Conclusions: This individual participant data meta-analysis demonstrated an increase in TSH with isolated TPOAb positivity and TgAb positivity, respectively, which was amplified for individuals positive for both antibodies. There was a dose-dependent association of TPOAbs, but not TgAbs, with TSH when adjusting for the other antibody. This supports current practice of using TPOAbs in initial laboratory testing of pregnant women suspected of autoimmune thyroid disease. However, studies on the differences between TPOAb- and TgAb-positive women are needed to fully understand the spectrum of phenotypes.

Diagnosis of thyroid nodules

Thyroid nodules are common, usually asymptomatic, and often pose minimal risk to the affected patient. However, 10-15% prove malignant and serve as the rationale for diagnostic assessment. Safely identifying and treating a relevant thyroid cancer through a cost-effective process is the primary goal of the treating practitioner. Ultrasound is the principal means of initial nodule assessment and should be performed when any thyroid nodule is suspected. Fine-needle aspiration provides further cytological determination of benign or malignant disease and is generally applied to nodules larger than 1-2 cm in diameter, on the basis of holistic risk assessment. The Bethesda System for Reporting Thyroid Cytopathology provides standardised terminology, which enhances communication among health-care providers and patients. Benign cytology is highly accurate, whereas indeterminate cytology could benefit from further application of molecular testing. The ultimate goal of diagnostic assessment of thyroid nodules is to accurately identify malignancy while avoiding overtreatment. Low-risk thyroid nodules can be safely monitored in many patients with minimal diagnostic intervention.

Management of thyroid nodules

In the past 30 years, there has been a substantial rise in the detection of thyroid nodules. Largely asymptomatic, thyroid nodules are most often incidental findings that typically pose minimal risk. Data supporting these findings show a rapid rise in the incidental detection of thyroid nodules and cancer, but minimal effect on mortality rates, despite treatment. These data imply that historical approaches to thyroid nodule and cancer care might at times include unnecessary or excessive care. To address this issue, the past decade has witnessed an increasingly conservative approach to nodule management, seeking to individualise care and provide the most focused intervention that leads to favourable outcomes. Benign nodules can be safely monitored with minimal, or long-interval follow-up imaging. Molecular testing should be considered for cytologically indeterminate nodules because of its ability to improve preoperative cancer risk determination and reduce unnecessary surgery. The treatment of biopsy-proven malignant nodules has become increasingly nuanced, since recommendations for near-total thyroidectomy are no longer routine. Hemithyroidectomy is now commonly considered when operative intervention is favoured. Some patients with small volume, isolated cancerous nodules are safely managed non-operatively with active monitoring. In summary, modern management strategies for thyroid nodular disease seek to incorporate the growing amount of available diagnostic and prognostic data, inclusive of demographic, radiological, pathological and molecular findings. Once obtained, an individualised management plan can be effectively formulated.

Thyroid Nodule Shape Independently Predicts Risk of Malignancy

CONTEXT

Predictive models of thyroid nodule cancer risk are presently based upon nodule composition, echogenicity, margins, and the presence of microcalcifications. Nodule shape has shown promise to be an additive factor helping determine the need for nodule biopsy.

OBJECTIVE

We sought to determine if calculation of a nodule's spherical shape independently associates with cancer risk.

METHODS

This prospective cohort study, conducted at a single large academic healthcare system in the United States, included patients with 1 or 2 clinically relevant thyroid nodules (predominantly solid and over 1 cm) presenting for diagnostic evaluation. Thyroid ultrasound, cytological evaluation with fine-needle biopsy, and/or histopathological examination on occasion of thyroid surgery were performed. We calculated the nodule's long to short ratio (spherical shape), and its association with tissue proven benign or malignant endpoints.

RESULTS

The long to short nodule ratio was significantly lower in malignant compared to benign nodules indicating greater risk of malignancy in more spherical nodules (1.63 ± 0.38 for malignant nodules vs 1.74 ± 0.47 for benign, P < 0.0001). The risk of malignancy continually increased as the long to short ratio approached a purely spherical ratio of 1.0 (ratio > 2.00, 14.6% cancer; ratio 1.51-2.00, 19.7%; ratio 1.00-1.50, 25.5%, P < 0.0001). In multiple regression analysis, younger age, male sex, and nodule's spherical shape were each independently associated with cancer risk.

CONCLUSION

The more a thyroid nodule is spherically shaped, as indicated by a long to short ratio approaching 1.0, the greater its risk of malignancy. This was independent of age, sex, and nodule size. Incorporating a nodule's sphericity in the risk stratification systems may improve individualized clinical decision making.

Optimizing allocation of curricular content across the Undergraduate & Graduate Medical Education Continuum

BACKGROUND

Medical educators struggle to incorporate socio-cultural topics into crowded curricula. The "continuum of learning" includes undergraduate and graduate medical education. Utilizing an exemplar socio-cultural topic, we studied the feasibility of achieving expert consensus among two groups of faculty (experts in medical education and experts in social determinants of health) on which aspects of the topic could be taught during undergraduate versus graduate medical education.

METHODS

A modified Delphi method was used to generate expert consensus on which learning objectives of social determinants of health are best taught at each stage of medical education. Delphi respondents included experts in medical education or social determinants of health. A survey was created using nationally published criteria for social determinants of health learning objectives. Respondents were asked 1) which learning objectives were necessary for every physician (irrespective of specialty) to develop competence upon completion of medical training and 2) when the learning objective should be taught. Respondents were also asked an open-ended question on how they made the determination of when in the medical education continuum the learning objective should be taught.

RESULTS

26 out of 55 experts (13 social determinants of health and 13 education experts) responded to all 3 Delphi rounds. Experts evaluated a total of 49 learning objectives and were able to achieve consensus for at least one of the two research questions for 45 of 49 (92%) learning objectives. 50% more learning objectives reached consensus for inclusion in undergraduate (n = 21) versus graduate medical education (n = 14).

CONCLUSIONS

A modified Delphi technique demonstrated that experts could identify key learning objectives of social determinants of health needed by all physicians and allocate content along the undergraduate and graduate medical education continuum. This approach could serve as a model for similar socio-cultural content. Future work should employ a qualitative approach to capture principles utilized by experts when making these decisions.

Clinical experience following implementation of routine SPECT-CT imaging following 131-iodine administration for thyroid cancer

Background

Planar scintigraphy has long been indicated in patients receiving I-131 therapy for thyroid cancer to determine the anatomic location of metastases. We studied our experience upon implementing additional single-photon emission (SPECT)-CT scanning in these patients.

Method

We performed a retrospective study of consecutive adult patients with newly diagnosed thyroid cancer treated with I-131 between 2011 and 2017. Radiologic findings detected with planar scintigraphy alone vs those identified with SPECT-CT scanning were primary endpoints.

Result

In this study, 212 consecutive patients with thyroid cancer were analyzed in two separate cohorts (107 planar scintigraphy alone and 105 planar scintigraphy with SPECT-CT). The addition of SPECT-CT resulted in more findings, both thyroid-related and incidental. However, we identified only 3 of 21 cases in which SPECT-CT provided an unequivocal additional benefit by changing clinical management beyond planar scintigraphy alone. No difference in the detection of distant metastatic disease or outcome was identified between cohorts.

Conclusion

Synergistic SPECT-CT imaging in addition to planar nuclear scintigraphy adds limited clinical value to thyroid cancer patients harboring a low risk of distant metastases, while frequently identifying clinically insignificant findings. These data from a typical cohort of patients receiving standard thyroid cancer care provide insight into the routine use of SPECT-CT in such patients.

Association between maternal thyroid function and risk of gestational hypertension and pre-eclampsia: a systematic review and individual-participant data meta-analysis

BACKGROUND

Adequate maternal thyroid function is important for an uncomplicated pregnancy. Although multiple observational studies have evaluated the association between thyroid dysfunction and hypertensive disorders of pregnancy, the methods and definitions of abnormalities in thyroid function tests were heterogeneous, and the results were conflicting. We aimed to examine the association between abnormalities in thyroid function tests and risk of gestational hypertension and pre-eclampsia.

METHODS

In this systematic review and meta-analysis of individual-participant data, we searched MEDLINE (Ovid), Embase, Scopus, and the Cochrane Database of Systematic Reviews from date of inception to Dec 27, 2019, for prospective cohort studies with data on maternal concentrations of thyroid-stimulating hormone (TSH), free thyroxine (FT₄), thyroid peroxidase (TPO) antibodies, individually or in combination, as well as on gestational hypertension, pre-eclampsia, or both. We issued open invitations to study authors to participate in the Consortium on Thyroid and Pregnancy and to share the individual-participant data. We excluded participants who had pre-existing thyroid disease or multifetal pregnancy, or were taking medications that affect thyroid function. The primary outcomes were documented gestational hypertension and pre-eclampsia. Individual-participant data were analysed using logistic mixed-effects regression models adjusting for maternal age, BMI, smoking, parity, ethnicity, and gestational age at blood sampling. The study protocol was registered with PROSPERO, CRD42019128585.

FINDINGS

We identified 1539 published studies, of which 33 cohorts met the inclusion criteria and 19 cohorts were included after the authors agreed to participate. Our study population comprised 46 528 pregnant women, of whom 39 826 (85·6%) women had sufficient data (TSH and FT₄ concentrations and TPO antibody status) to be classified according to their thyroid function status. Of these women, 1275 (3·2%) had subclinical hypothyroidism, 933 (2·3%) had isolated hypothyroxinaemia, 619 (1·6%) had subclinical hyperthyroidism, and 337 (0·8%) had overt hyperthyroidism. Compared with euthyroidism, subclinical hypothyroidism was associated with a higher risk of pre-eclampsia (2·1% vs 3·6%; OR 1·53 [95% CI 1·09-2·15]). Subclinical hyperthyroidism, isolated hypothyroxinaemia, or TPO antibody positivity were not associated with gestational hypertension or pre-eclampsia. In continuous analyses, both a higher and a lower TSH concentration were associated with a higher risk of pre-eclampsia (p=0·0001). FT₄ concentrations were not associated with the outcomes measured.

INTERPRETATION

Compared with euthyroidism, subclinical hypothyroidism during pregnancy was associated with a higher risk of pre-eclampsia. There was a U-shaped association of TSH with pre-eclampsia. These results quantify the risks of gestational hypertension or pre-eclampsia in women with thyroid function test abnormalities, adding to the total body of evidence on the risk of adverse maternal and fetal outcomes of thyroid dysfunction during pregnancy. These findings have potential implications for defining the optimal treatment target in women treated with levothyroxine during pregnancy, which needs to be assessed in future interventional studies.

FUNDING

Arkansas Biosciences Institute and Netherlands Organization for Scientific Research.

Service learning and the medical student affective domain

BACKGROUND

The Association of American Medical College (AAMC) requires all students to demonstrate four core attributes: knowledge, skills, altruism and dutifulness. A formal service-learning curriculum may serve to explicitly foster altruism and dutifulness in the affective domain of Bloom's taxonomy as well as proactively improve student well-being.

APPROACH

All Harvard Medical School students enrolled in the Principal Clinical Experience (PCE) programme in the 2018-2019 academic year at Brigham and Women's Hospital were excused from clerkship responsibilities and given the opportunity to participate in a half-day team-based community-service intervention at a not-for-profit organisation in Boston, MA. Following the service-learning initiative, we examined student compassion, civic responsibility, well-being and team cooperativeness using validated survey questions, supplemented by free-text feedback.

EVALUATION

Forty-five of the 55 PCE students (82%) attended the outing. Overall, 68% of students found the outing to be valuable and 23% somewhat valuable. On a scale of 0-20, students reported very high self-perception of compassion (mean = 19.9), civic responsibility (mean = 19.7) and team development and composition (mean = 19.1), after the event. Students reported lower perceptions of personal well-being (mean = 17.5), but emotional wellness was the most frequently mentioned theme in open response.

IMPLICATIONS

Incorporation of a team-based service-learning activity contributes to the students' community understanding, empathy and class team building. Utilisation of a published framework in the development of this initiative likely contributed to its success. Given our findings, we plan further expansion of this service learning longitudinally through the 4-year curriculum to potentially strengthen the affective domain for students further.

Educational adaptation to clinical training during the COVID-19 pandemic: a process analysis

BACKGROUND

The COVID-19 pandemic is unprecedented in terms of the extent and rapidity of the disruption forced upon formal clinical education, most notably the extensive transition of clinical skills learning to interactive video-based clinical education.

METHODS

In a phenomenologic study, we used thematic analysis to explore the COVID-19 disruption to clinical training and understand processes relating to adaptation in a large academic medical center. We conducted semi-structured interviews with 14 clinical teachers and 16 trainees representing all levels of clinical learning. Interviews occurred within the initial three months of the crisis, and data were analyzed following a thematic analysis coding process.

RESULTS

We constructed eight themes synthesizing our participants' perceptions of the immediate unanticipated disruption, noting in the process their alignment with a change management framework. These included: urgency in adapting, with an obvious imperative for change; overcoming inconsistent involvement and support through the formation of self-organized frontline coalitions; attempts to develop strategy and vision via initially reactive but eventually consistent communication; empowering a volunteer army through co-creation and a flattened hierarchy; and efforts to sustain improvement and positive momentum with celebration of trial, error, and growth. The majority of participants found positive outcomes resulting from the tumultuous change process. Moreover, they were now more readily accepting of change, and tolerant of the ambiguous and iterative nature inherent in the education change process. Many anticipated that some innovation would, or would at least deserve to, continue post- crisis.

CONCLUSIONS

The COVID-19 pandemic afforded an opportunity to study the content and process of change during an active crisis. In this case of clinical education, our findings provide insight into the ways an academic medical system adapts to unanticipated circumstances. We found alignment with broader organizational change management models and that, compared with crisis management models (and their shorter term focus on resolving such crises), stakeholders self-organized in a reliable manner that carries the potential advantage of preserving such beneficial change.

Vitamin D and marine omega 3 fatty acid supplementation and incident autoimmune disease: VITAL randomized controlled trial

OBJECTIVE

To investigate whether vitamin D and marine derived long chain omega 3 fatty acids reduce autoimmune disease risk.

DESIGN

Vitamin D and omega 3 trial (VITAL), a nationwide, randomized, double blind, placebo controlled trial with a two-by-two factorial design.

SETTING

Nationwide in the United States.

PARTICIPANTS

25 871 participants, consisting of 12 786 men ≥50 years and 13 085 women ≥55 years at enrollment.

INTERVENTIONS

Vitamin D (2000 IU/day) or matched placebo, and omega 3 fatty acids (1000 mg/day) or matched placebo. Participants self-reported all incident autoimmune diseases from baseline to a median of 5.3 years of follow-up; these diseases were confirmed by extensive medical record review. Cox proportional hazard models were used to test the effects of vitamin D and omega 3 fatty acids on autoimmune disease incidence.

MAIN OUTCOME MEASURES

The primary endpoint was all incident autoimmune diseases confirmed by medical record review: rheumatoid arthritis, polymyalgia rheumatica, autoimmune thyroid disease, psoriasis, and all others.

RESULTS

25 871 participants were enrolled and followed for a median of 5.3 years. 18 046 self-identified as non-Hispanic white, 5106 as black, and 2152 as other racial and ethnic groups. The mean age was 67.1 years. For the vitamin D arm, 123 participants in the treatment group and 155 in the placebo group had a confirmed autoimmune disease (hazard ratio 0.78, 95% confidence interval 0.61 to 0.99, P=0.05). In the omega 3 fatty acids arm, 130 participants in the treatment group and 148 in the placebo group had a confirmed autoimmune disease (0.85, 0.67 to 1.08, P=0.19). Compared with the reference arm (vitamin D placebo and omega 3 fatty acid placebo; 88 with confirmed autoimmune disease), 63 participants who received vitamin D and omega 3 fatty acids (0.69, 0.49 to 0.96), 60 who received only vitamin D (0.68, 0.48 to 0.94), and 67 who received only omega 3 fatty acids (0.74, 0.54 to 1.03) had confirmed autoimmune disease.

CONCLUSIONS

Vitamin D supplementation for five years, with or without omega 3 fatty acids, reduced autoimmune disease by 22%, while omega 3 fatty acid supplementation with or without vitamin D reduced the autoimmune disease rate by 15% (not statistically significant). Both treatment arms showed larger effects than the reference arm (vitamin D placebo and omega 3 fatty acid placebo).

STUDY REGISTRATION

ClinicalTrials.gov NCT01351805 and NCT01169259.

Global Med Ed Café: A safe space for conversations

BACKGROUND

Communities of practice foster knowledge sharing, scholarly collaboration, mentoring and professional identify formation. Easier access to technology overall and the desire to engage with peers during the pandemic have increased opportunities to engage in virtual global conversations.

APPROACH

The Brigham Education Institute designed and implemented a series of six bimonthly, 1-hour 'Global Medical Education Cafés' between September 2020 and June 2021. They were offered on the Zoom platform and featured a core educational topic led by one or two discussants, followed by small group interactions surrounding specific questions or challenges. Discussants were selected based on their international reputation and recognition as health professions education scholars and leaders with expertise in specific areas. Each café was advertised through newsletters, social media, educational email lists and open to educators from any healthcare discipline or geographical region.

EVALUATION

Between 26 and 41 participants attended each session from 12 countries representing five continents. Content analysis of preliminary education evaluation data from chats and reflective narratives identified four key themes: (1) exciting interactive format; (2) sense of worldwide community; (3) safe space for conversations; and (4) strong moderators facilitating engaging peer conversations.

IMPLICATIONS

The series leaders aimed to emphasise inclusive, non-hierarchical and cross-cultural conversations. Preliminary evaluation suggests that this goal was achieved; these will remain priorities in future series. Educators worldwide can organise similar events with minimal resources. A safe space for conversations and open-mindedness to learning from a variety of learning and societal cultures are likely essential elements for success.

Point of Care Measurement of Body Mass Index and Thyroid Nodule Malignancy Risk Assessment

BACKGROUND

Large scale epidemiology studies have suggested obesity may increase the risk of thyroid cancer, though no prospective analyses using real-world measurement of BMI at a time proximate to initial thyroid nodule evaluation have been performed.

METHODS

We performed a prospective, cohort analysis over 3 years of consecutive patients presenting for thyroid nodule evaluation. We measured BMI proximate to the time of initial evaluation and correlated this with the final diagnosis of benign or malignant disease. We further correlated patient BMI with aggressivity of thyroid cancer, if detected.

RESULTS

Among 1,259 consecutive patients with clinically relevant nodules, 199(15%) were malignant. BMI averaged 28.6 kg/m² (SD: 6.35, range:16.46-59.26). There was no correlation between the measurement of BMI and risk of thyroid cancer (p=0.58) as mean BMI was 28.9 kg/m² and 28.6 kg/m² in cancerous and benign cohorts, respectively. Similarly, BMI did not predict aggressive thyroid cancer (p=0.15). While overall nodule size was associated with increased BMI (p<0.01), these data require further validation as obesity may hinder nodule detection until large.

CONCLUSION

In contrast to findings published from large scale association studies drawn from national databases, these prospective data of consecutive patients presenting for nodule evaluation detect no association of obesity (as measured by BMI) with thyroid cancer. Real time measurement of BMI at the time of thyroid nodule evaluation does not contribute to cancer risk assessment.

The Role of Thyroid in Renovascular Function: Independent Association of Serum TSH With Renal Plasma Flow

CONTEXT

There are well-established interactions between the thyroid and the kidney. Thyroid hypofunction is associated with reduced renal plasma flow (RPF), and hypothyroidism is highly prevalent in chronic kidney disease; however, less is known about the thyroid-kidney axis in the euthyroid state.

OBJECTIVE

This work aimed to study the association of thyroid function with renovascular parameters in a well-phenotyped cohort of euthyroid normotensive and hypertensive individuals.

METHODS

This cross-sectional, multicenter study of the HyperPATH Consortium took place in 5 US and European academic institutions. A total of 789 individuals, aged 18 to 65 years, with serum thyrotropin (TSH) 0.4 to 5.5 mIU/L, participated; individuals with uncontrolled or secondary hypertension or on medication affecting the hypothalamus-pituitary-thyroid axis were excluded. Hemodynamic parameters including RPF, thyroid function testing, and the Thr92Ala deiodinase 2 (D2) polymorphism were assessed in the setting of a liberal and restricted salt diet. We searched for associations between thyroid function and renovascular parameters and accounted for confounding factors, such as older age, hypertension, and diabetes.

RESULTS

Serum TSH was inversely associated with RPF assessed in the setting both of liberal and restricted salt diets. This association remained significant and independent when accounting for confounding factors, whereas free thyroxine index (fTI) and the Thr92Ala polymorphism, associated with lower D2 catalytic activity and disrupted thyroid hormone tissue availability, were not independently associated with RPF. Serum TSH remained an independent predictor of RPF on a liberal salt diet when the analysis was restricted to healthy young individuals.

CONCLUSION

Serum TSH levels, but not fTI nor the Thr92Ala D2 polymorphism, were independently inversely associated with RPF in individuals of the HyperPATH Consortium. These findings suggest a direct interconnection between TSH and renovascular dynamics even with TSH within reference range, warranting further investigation.

Building Longitudinal Relationships Into a Traditional Block Clerkship Model: A Mixed-Methods Study

PURPOSE

The authors describe the implementation of the novel Longitudinal Clinical Experiences with Patients (LCEP) curriculum, designed to integrate continuity and longitudinal patient relationships into a traditional block clerkship (BC), and present a mixed-methods analysis evaluating program effectiveness to assess its feasibility, value, and impact.

METHOD

This was a mixed-methods study of 54 Harvard Medical School students who participated in the LCEP during their core clerkship (third) year during the 2013-2014 academic year. Fifty-two students responded to an electronic survey about the patients they followed during the LCEP. Forty-two students completed confidential live interviews. Unique groups of 13-15 students were interviewed at 3 times during the year to assess students' perceptions of the LCEP over time. The data were analyzed using a content analysis framework.

RESULTS

On average, students followed 3.3 LCEP patients over the clerkship year. Ninety-four percent (n = 49/52) of students were able to follow 2 or more patients longitudinally. Most students met their longitudinal patient in the inpatient setting (71%, n = 37/52). Subsequent encounters were most often in the ambulatory setting. Students described scheduling logistics as key to the success or failure of the program. Many students described the challenges of competing priorities between their BC responsibilities and longitudinal opportunities. Students found the LCEP deepened their understanding of the patient experience, the health care system, and disease progression. Over the course of an academic year, an increased proportion of students (60%) highlighted understanding the patient experience as a core value obtained through the LCEP.

CONCLUSIONS

The LCEP was feasible and proved successful in promoting longitudinal patient relationships within a traditional BC model. Prioritizing the depth of experience with a smaller number of patients may reduce the barriers described by students. The results suggest that such a hybrid program promotes patient-centeredness.

Oncogenic Mutations in PI3K/AKT/mTOR Pathway Effectors Associate with Worse Prognosis in BRAFV600E -Driven Papillary Thyroid Cancer Patients

PURPOSE

The extent to which routine genomic sequencing can identify relevant secondary genomic alterations among BRAF^V600E -mutant papillary thyroid carcinoma (PTC) is unknown. Such markers would prove highly valuable for prognostic purposes.

EXPERIMENTAL DESIGN

We reviewed clinicopathologic data of 225 patients with BRAF^V600E -mutant PTC and integrated them with genomic data derived from targeted next-generation sequencing (NGS) on tumor specimens. We defined patient subgroups based on bona fide secondary oncogenic events (separate from BRAF^V600E ) and compared their clinical features and outcomes with those without additional oncogenic alterations.

RESULTS

Additional oncogenic alterations were identified in 16% of tumors. Patients in the "BRAF+additional mutations" group were more likely to be at high American Thyroid Association (ATA) risk of recurrence (48.6% vs. 17.6%; P = 0.0009), had larger baseline tumor (2.7 vs. 1.9 cm; P = 0.0005) and more advanced stage at presentation (14.3% vs. 1.1% stage 4; P < 0.0001). Importantly, over a 65-month follow-up, disease-specific mortality (DSM) was increased when additional mutations were identified (13.8% vs. 1.4% in the BRAF-only group; P = 0.005). Separately, we identified a subcluster of patients harboring oncogenic mutations in key effectors of the PI3K/AKT/mTOR pathway, which were independently associated with DSM (OR = 47.9; 95% confidence interval, 3.5-1,246.5; P = 0.0043).

CONCLUSIONS

Identification of additional PIK3/AKT/mTOR alterations in patients with BRAF^V600E -mutant PTC provides important and actionable prognostic risk stratification. These data support genomic profiling of PTC tumors to inform prognosis and clinical strategy.

Papillary Thyroid Carcinoma with High-Grade Features Versus Poorly Differentiated Thyroid Carcinoma: An Analysis of Clinicopathologic and Molecular Features and Outcome

Background: Similar to poorly differentiated thyroid carcinoma (PDTC), papillary thyroid carcinoma with high-grade features (PTC HGF) demonstrates increased mitotic activity and/or necrosis; however, PTC HGF is excluded from the World Health Organization (WHO) definition of PDTC based on maintained nuclear features of PTC. Methods: Consecutive tumors that met criteria for PTC HGF, defined as tumors with maintained nuclear features of PTC and mitoses numbering 5 or more per 10 contiguous high-power fields and/or tumor necrosis, and PDTC (defined as per the WHO criteria) were identified. Clinicopathologic characteristics, follow-up data, and targeted next-generation sequencing results were compared between groups. Results: There were 15 PTC HGF and 47 PDTC. PTC HGF was associated with a higher rate of pT4 disease (53% vs. 13%, p = 0.0027) and lymph node metastases (73% vs. 38%, p = 0.049). The disease-specific survival was worse for patients with PTC HGF compared with those with PDTC using Kaplan-Meier estimation (p < 0.001) and was worse in subgroup analysis evaluating patients with widely invasive PDTC (i.e., those with a similar rate of pT4 disease) and PTC HGF (p = 0.040). PTC HGF had a higher BRAF^V600E mutation rate (42% vs. 3%; p = 0.003), a trend toward more gene fusions (25% vs. 3%; p = 0.052), and a higher rate of relative gain of 1q (67% vs. 15%; p = 0.002) than PDTC. Conclusions: Our results demonstrate that PTC HGF are important to recognize based on their aggressive behavior. The molecular differences between PTC HGF and PDTC suggest that PTC HGF should be considered a distinct group from PDTC.

Role of Sonographic Characteristics of Thyroid Bed Lesions Identified Following Thyroidectomy in the Diagnosis or Exclusion of Recurrent Cancer

Background US of the thyroid bed in patients with thyroid cancer often depicts small lesions, but it is unclear whether US characteristics of lesions can help predict cancer recurrence. Purpose To determine whether size or US features of lesions in the thyroid bed after thyroidectomy in conjunction with clinical features can help predict thyroid cancer recurrence. Materials and Methods With use of a US reporting database, all patients imaged between July 2006 and June 2016 with an indication of post-thyroidectomy follow-up were retrospectively identified. Recorded data included patient demographic characteristics; date of thyroidectomy; thyroid cancer type; presence, size, and US characteristics of thyroid bed lesions; and results of fine-needle aspiration (FNA). Images were reviewed for lesions that underwent FNA. The Fisher exact test was used for analysis. Results A total of 1885 patients (mean age ± standard deviation, 48 years ± 15; 1493 female patients) underwent 5732 US examinations. Most patients (1541 of 1885 [82%]) had papillary cancer. Overall, 3163 thyroid bed lesions were reported in 5732 US examinations (40.4%). More than half of these lesions (1860 of 3163 [58.8%]) had a maximum measurement of 6 mm or greater. FNA was performed in 144 of the 3163 lesions (4.6%), of which 61 (42.4%) were malignant, 33 (22.9%) were benign, and 50 (34.7%) were nondiagnostic. Five nondiagnostic lesions eventually proved malignant. Only the presence of punctate echogenicities in the lesion (28 of 61 malignant lesions [45.9%]; three of 33 benign lesions [9%]; 12 of 50 nondiagnostic lesions [24%]; P < .001) or the history of positive lymph nodes at thyroidectomy (44 of 61 malignant lesions [72.1%]; 10 of 33 benign lesions [30%]; 19 of 50 nondiagnostic lesions [38%]; P < .001) were associated with malignancy. Of 3019 thyroid bed lesions that did not undergo FNA, three were malignant and 2248 showed no growth at follow-up US ranging from 6 months to 10 years and are presumed benign. Of the 1303 lesions smaller than 6 mm, only two (0.2%) were malignant. Conclusion Small lesions are commonly found in the thyroid bed after thyroidectomy, and most are likely to be benign. Lesions smaller than 6 mm with no punctate echogenicities had a minimal risk for malignancy. © RSNA, 2021 See also the editorial by Grant and Malhi in this issue.

Consequences of Iodine Deficiency and Excess in Pregnancy and Neonatal Outcomes: A Prospective Cohort Study in Rio de Janeiro, Brazil

Background: Insufficient or excessive iodine intake during gestation may compromise adaptive mechanisms in maternal thyroid function and lead to adverse pregnancy outcomes. In this context, we aimed to study the effects of maternal iodine status in the first and third trimesters of gestation on obstetric and neonatal outcomes in an iodine-sufficient population in Rio de Janeiro, Brazil. Methods: A total of 214 pregnant women in the first trimester of gestation were enrolled and prospectively followed until delivery between 2014 and 2017. All participants were ≥18 and ≤35 years, had a spontaneous single pregnancy, and had no history of thyroid or other chronic diseases, nor were they taking iodine-containing supplements at enrollment. In the first trimester, we obtained clinical information and determined thyroid function and the urinary iodine concentration (UIC) of the participants. Thyroid function and UIC were reassessed in the third trimester. Iodine status was determined by the median of UIC obtained from six urine spot samples by the inductively coupled plasma mass spectrometry method. Pregnancy and neonatal outcomes and delivery information were obtained from medical records. Results: The median UIC in the whole population was 219.7 μg/L. The prevalence of UIC <150 μg/L was 17.2%, and 38.7% had UIC ≥250 μg/L. Gestational diabetes (GDM) was higher in the group with UIC 250-499 μg/L (n = 77) compared with the group with UIC 150-249 μg/L (n = 94) (20.3% vs. 9.7%, p < 0.05). Ultimately, UIC ≥250 μg/L was an independent risk factors for GDM (relative risk [RR] = 2.9 [confidence interval, CI = 1.1-7.46], p = 0.027) and hypertensive disorders of pregnancy (HDP) (RR = 4.6 [CI = 1.1-18.0], p = 0.029). Among 196 live-born newborns, lower birth length was observed in infants whose mothers had UIC <150μg/L (n = 37) in the first trimester compared with those with UIC 150-249 μg/L (n = 86) (median interquartile range: 48.0 [2.2] vs. 49.0 [4.0] cm, p = 0.01). Maternal UIC <150 μg/L was negatively associated with birth length of newborns (Exp (B) = 0.33 [CI = 0.1-0.9], p = 0.03). Conclusions: In a population whose median iodine intake is sufficient, extensive individual variation occurs. Such abnormalities are associated with increased GDM and HDP when UIC is ≥250 μg/L, and lower infant birth length when UIC is <150 μg/L.

The Harvard Medical School Pathways Curriculum: Reimagining Developmentally Appropriate Medical Education for Contemporary Learners

As the U.S. health care system changes and technology alters how doctors work and learn, medical schools and their faculty are compelled to modify their curricula and teaching methods. In this article, educational leaders and key faculty describe how the Pathways curriculum was conceived, designed, and implemented at Harvard Medical School. Faculty were committed to the principle that educators should focus on how students learn and their ability to apply what they learn in the evaluation and care of patients. Using the best evidence from the cognitive sciences about adult learning, they made major changes in the pedagogical approach employed in the classroom and clinic. The curriculum was built upon 4 foundational principles: to enhance critical thinking and provide developmentally appropriate content; to ensure both horizontal integration between courses and vertical integration between phases of the curriculum; to engage learners, foster curiosity, and reinforce the importance of student ownership and responsibility for their learning; and to support students' transformation to a professional dedicated to the care of their patients and to their obligations for lifelong, self-directed learning.The practice of medicine is rapidly evolving and will undoubtedly change in multiple ways over the career of a physician. By emphasizing personal responsibility, professionalism, and thinking skills over content transfer, the authors believe this curriculum will prepare students not only for the first day of practice but also for an uncertain future in the biological sciences, health and disease, and the nation's health care system, which they will encounter in the decades to come.

Clinical considerations for the treatment of secondary differentiated thyroid carcinoma in childhood cancer survivors

The incidence of differentiated thyroid carcinoma (DTC) has increased rapidly over the past several years. Thus far, the only conclusively established risk factor for developing DTC is exposure to ionizing radiation, especially when the exposure occurs in childhood. Since the number of childhood cancer survivors (CCS) is increasing due to improvements in treatment and supportive care, the number of patients who will develop DTC after surviving childhood cancer (secondary thyroid cancer) is also expected to rise. Currently, there are no recommendations for management of thyroid cancer specifically for patients who develop DTC as a consequence of cancer therapy during childhood. Since complications or late effects from prior cancer treatment may elevate the risk of toxicity from DTC therapy, the medical history of CCS should be considered carefully in choosing DTC treatment. In this paper, we emphasize how the occurrence and treatment of the initial childhood malignancy affects the medical and psychosocial factors that will play a role in the diagnosis and treatment of a secondary DTC. We present considerations for clinicians to use in the management of patients with secondary DTC, based on the available evidence combined with experience-based opinions of the authors.

Histopathologic Features and Clinical Outcome of Anaplastic Thyroid Carcinoma with a Minor Anaplastic Component

Although prior studies have reported that patients with anaplastic thyroid carcinoma (ATC) with a focal anaplastic component may have a prolonged survival compared to other ATC patients, the outcome data are limited. We evaluated a cohort of ATC resected between 2003 and 2018. Tumor slides were reviewed to confirm the diagnosis and to identify cases with a minor ATC component (defined as comprising < 10% of the tumor). We evaluated the clinical outcome of these patients compared to that of all other cohort patients (characterized as having conventional ATC). Our cohort was composed of 24 cases of ATC that underwent resection, including 8 (33%) with a minor ATC component. Tumors with a minor ATC component were predominantly associated with papillary thyroid carcinoma. For patients with tumors with a minor ATC component, the 1-year and 2-year survival rates and median survival for patients who died of disease were 88%, 43%, and 17 months (range 6-73 months), respectively. In comparison, for patients with conventional ATC, the 1-year and 2-year survival rates and median survival for patients who died of disease were 56%, 44%, and 7 months (range 2-26 months), respectively. There was no difference in 1- and 2-year survival or overall survival by Kaplan-Meier analysis for patients with tumors with a minor ATC component and those with conventional ATC. In conclusion, the difference in overall survival between ATC groups in our cohort was not significant; however, this could be due to the small cohort size or due to characteristics of our group with a minor ATC component; that is, no tumors in this group were limited to the thyroid (stage IVA), resectability with negative margins was infrequent, and 38% of this group had distant metastases at diagnosis (stage IVC).

Completion Thyroidectomy is Less Common Following Updated 2015 American Thyroid Association Guidelines

BACKGROUND

The 2015 American Thyroid Association (ATA) guidelines recommended that low-risk, differentiated thyroid cancers (DTC) between 1 and 4 cm may be treated with thyroid lobectomy alone. We sought to determine the effect of these guideline changes on the rate of completion thyroidectomy (CT) for low-risk DTC and factors influencing surgical decision-making.

METHODS

All patients from 2014 to 2018 who received an initial thyroid lobectomy at our institution with final pathology demonstrating DTC were included. Patients were divided into "pre" and "post" guideline cohorts (2014-2015 and 2016-2018, respectively). The rate of CT was compared between the two cohorts. Patient demographics and tumor characteristics were examined for association with CT.

RESULTS

A total of 163 patients met study criteria: 63 patients in the 2014-2015 ("pre") and 100 in the 2016-2018 ("post") group. In the "pre" period, 41 (65.1%) patients received CT compared with 43 (43.0%) in the "post" period (p < 0.01)-a 34% decrease in the rate of completion surgery (p < 0.01). Of low-risk patients with DTC between 1 and 4 cm in size, 17 of 35 (48.6%) received CT in the "pre" period compared with 15 of 60 (25.0%) in the post period-a 48.6% decrease in the rate of completion surgery (p = 0.02). Greater tumor size, capsular invasion, and multifocality were associated with CT in low-risk "post" guideline patients (p < 0.05 for all).

CONCLUSIONS

The rate of CT decreased significantly by 48.6% for low-risk patients with DTC between 1 and 4 cm, demonstrating recognition of the 2015 ATA guidelines. However, 25% of these patients underwent CT, suggesting additional factors influencing the decision for further treatment.

Association of maternal thyroid function with birthweight: a systematic review and individual-participant data meta-analysis

BACKGROUND

Adequate transplacental passage of maternal thyroid hormone is important for normal fetal growth and development. Maternal overt hypothyroidism and hyperthyroidism are associated with low birthweight, but important knowledge gaps remain regarding the effect of subclinical thyroid function test abnormalities on birthweight-both in general and during the late second and third trimester of pregnancy. The aim of this study was to examine associations of maternal thyroid function with birthweight.

METHODS

In this systematic review and individual-participant data meta-analysis, we searched MEDLINE (Ovid), Embase, Web of Science, the Cochrane Central Register of Controlled Trials, and Google Scholar from inception to Oct 15, 2019, for prospective cohort studies with data on maternal thyroid function during pregnancy and birthweight, and we issued open invitations to identify study authors to join the Consortium on Thyroid and Pregnancy. We excluded participants with multiple pregnancies, in-vitro fertilisation, pre-existing thyroid disease or thyroid medication usage, miscarriages, and stillbirths. The main outcomes assessed were small for gestational age (SGA) neonates, large for gestational age neonates, and newborn birthweight. We analysed individual-participant data using mixed-effects regression models adjusting for maternal age, BMI, ethnicity, smoking, parity, gestational age at blood sampling, fetal sex, and gestational age at birth. The study protocol was pre-registered at the International Prospective Register of Systematic Reviews, CRD42016043496.

FINDINGS

We identified 2526 published reports, from which 36 cohorts met the inclusion criteria. The study authors for 15 of these cohorts agreed to participate, and five more unpublished datasets were added, giving a study population of 48 145 mother-child pairs after exclusions, of whom 1275 (3·1%) had subclinical hypothyroidism (increased thyroid stimulating hormone [TSH] with normal free thyroxine [FT4]) and 929 (2·2%) had isolated hypothyroxinaemia (decreased FT4 with normal TSH). Maternal subclinical hypothyroidism was associated with a higher risk of SGA than was euthyroidism (11·8% vs 10·0%; adjusted risk difference 2·43%, 95% CI 0·43 to 4·81; odds ratio [OR] 1·24, 1·04 to 1·48; p=0·015) and lower mean birthweight (mean difference -38 g, -61 to -15; p=0·0015), with a higher effect estimate for measurement in the third trimester than in the first or second. Isolated hypothyroxinaemia was associated with a lower risk of SGA than was euthyroidism (7·3% vs 10·0%, adjusted risk difference -2·91, -4·49 to -0·88; OR 0·70, 0·55 to 0·91; p=0·0073) and higher mean birthweight (mean difference 45 g, 18 to 73; p=0·0012). Each 1 SD increase in maternal TSH concentration was associated with a 6 g lower birthweight (-10 to -2; p=0·0030), with higher effect estimates in women who were thyroid peroxidase antibody positive than for women who were negative (pinteraction=0·10). Each 1 SD increase in FT4 concentration was associated with a 21 g lower birthweight (-25 to -17; p<0·0001), with a higher effect estimate for measurement in the third trimester than the first or second.

INTERPRETATION

Maternal subclinical hypothyroidism in pregnancy is associated with a higher risk of SGA and lower birthweight, whereas isolated hypothyroxinaemia is associated with lower risk of SGA and higher birthweight. There was an inverse, dose-response association of maternal TSH and FT4 (even within the normal range) with birthweight. These results advance our understanding of the complex relationships between maternal thyroid function and fetal outcomes, and they should prompt careful consideration of potential risks and benefits of levothyroxine therapy during pregnancy.

FUNDING

Netherlands Organization for Scientific Research (grant 401.16.020).

A phase II study of nivolumab (N) plus ipilimumab (I) in radioidine refractory differentiated thyroid cancer (RAIR DTC) with exploratory cohorts in anaplastic (ATC) and medullary thyroid cancer (MTC)

6513

Background: Treatment options for aggressive TC are limited. Pre-clinical data suggests efficacy of CTLA-4 plus PD-1 blockade in aggressive RAIR TC. Methods: This investigator initiated phase II study tested N (3mg/kg every 2 weeks) plus I (1mg/kg every 6 weeks) until disease progression or completion of 24 mo of treatment in RAIR differentiated TC including poorly differentiated TC (PDTC) with exploratory cohorts in anaplastic (ATC) and medullary TC (MTC). Radiographic response rate by RECIST v1.1 (CR+PR) was primary endpoint. At least 6 pts with disease response among n=32 DTC provided 84% power to distinguish between a 10% and a 25% RR (one-sided 9% binomial test). Results: Accrual is complete with n=32 patients with DTC, 10 with ATC and 7 with MTC enrolled between October 2017 and May 2019. Thirty-two DTC included: n=17 papillary, n=7 Hurthle, n=4 follicular TC, n=4 PDTC. Among n=49, median (range) age was 65 (30-88), 51% (25/49) were female. To date, in DTC, 3/32 achieved a PR (n=2 Hurthle and n=1 PDTC), 9.4% RR (.95CI:2%-25%). One near complete response has been observed. Among pts w ATC, 3/ 10 profound PR by RECIST occurred (30% RR, .95CI: 7%-65%). Among them, two remain without clear evidence of disease at 26 and 13 mo after treatment start. No PR's were observed in MTC. Most frequent grade 3-4 TRAEs were as expected and included increased lipase (n=8), increased serum amylase (n=4). There was an unexpected number of treatment related adrenal insufficiency (AI) (n=4) which was associated with long PFS (range 10.1—16.4+mo). Conclusions: N+I appears to have considerable activity in ATC. In unselected RAIR DTC, activity was low but responses were seen in PDTC and Hurthle cell TC. Exceptional responses with prolonged remissions were observed. Clinical trial information: NCT03246958 .

Defining thyroid spherules: A benign cytomorphologic feature that mimics microfollicles

BACKGROUND

Distinctive rounded structures termed spherules have been observed in thyroid fine-needle aspiration (FNA) samples. Although they are often small and interpreted as microfollicles, spherules are notable for the even spacing of the follicular cells along the perimeter of the structure. Because they have an orderly architectural arrangement, it has been hypothesized that spherules are benign and do not carry the same risk of malignancy that traditional microfollicles do. The aim of this study was to identify the clinical significance and histopathologic correlate of spherules.

METHODS

Thyroid FNAs (n = 637) with an interpretation of atypia of undetermined significance (AUS) were reviewed for the presence of spherules, which were defined as small follicles with a rounded, smooth, sharply defined outer contour, evenly spaced nuclei, and a 3-dimensional appearance. Cases were included if spherules accounted for >50% of follicular cell arrangements. Clinical, histopathologic, molecular, and sonographic follow-up data were obtained.

RESULTS

Twenty-five spherule cases were identified, and they represented 3.9% of all AUS cases reviewed. All 24 cases with follow-up had a benign outcome. Eleven were tested with the Afirma gene expression classifier; 8 were benign according to the gene expression classifier, and 3 were suspicious but histologically benign after surgical resection. Four additional cases were histologically benign after surgery. Five patients had repeat benign cytology. Four patients had repeat stable ultrasound findings.

CONCLUSIONS

Thyroid nodules diagnosed as AUS, if composed predominantly of spherules, are associated with a benign outcome. Recognizing this distinctive cytomorphologic finding may help to reduce the number of FNAs interpreted as AUS and save patients from unnecessary additional testing and surgery.

A Cohort Analysis of Clinical and Ultrasound Variables Predicting Cancer Risk in 20,001 Consecutive Thyroid Nodules

CONTEXT

Assessing thyroid nodules for malignancy is complex. The impact of patient and nodule factors on cancer evaluation is uncertain.

OBJECTIVES

To determine precise estimates of cancer risk associated with clinical and sonographic variables obtained during thyroid nodule assessment.

DESIGN

Analysis of consecutive adult patients evaluated with ultrasound-guided fine-needle aspiration for a thyroid nodule ≥1 cm between 1995 and 2017. Demographics, nodule sonographic appearance, and pathologic findings were collected.

MAIN OUTCOME MEASURES

Estimated risk for thyroid nodule malignancy for patient and sonographic variables using mixed-effect logistic regression.

RESULTS

In 9967 patients [84% women, median age 53 years (range 18 to 95)], thyroid cancer was confirmed in 1974 of 20,001 thyroid nodules (9.9%). Significant ORs for malignancy were demonstrated for patient age <52 years [OR: 1.82, 95% CI (1.63 to 2.05), P < 0.0001], male sex [OR: 1.68 (1.45 to 1.93), P < 0.0001], nodule size [OR: 1.30 (1.14 to 1.49) for 20 to 19 mm, OR: 1.59 (1.34 to 1.88) for 30 to 39 mm, and OR: 1.71 (1.43 to 2.04) for ≥40 mm compared with 10 to 19 mm, P < 0.0001 for all], cystic content [OR: 0.43 (0.37 to 0.50) for 25% to 75% cystic and OR: 0.21 (0.15 to 0.28) for >75% compared with predominantly solid, P < 0.0001 for both], and the presence of additional nodules ≥1 cm [OR: 0.69 (0.60 to 0.79) for two nodules, OR: 0.41 (0.34 to 0.49) for three nodules, and OR: 0.19 (0.16 to 0.22) for greater than or equal to four nodules compared with one nodule, P < 0.0001 for all]. A free online calculator was constructed to provide malignancy-risk estimates based on these variables.

CONCLUSIONS

Patient and nodule characteristics enable more precise thyroid nodule risk assessment. These variables are obtained during routine initial thyroid nodule evaluation and provide new insights into individualized thyroid nodule care.

Discordance of serological and sonographic markers for Hashimoto's thyroiditis with gold standard histopathology

OBJECTIVE

To investigate the concordance of serologic and sonographic evidence of Hashimoto's thyroiditis with its gold standard histopathologic identification.

DESIGN

We performed a retrospective analysis on a cohort of 825 consecutive patients in whom TPOAb and thyroid ultrasound were performed, and in whom thyroid nodule evaluation led to surgical and histopathologic analysis. The presence or absence of Hashimoto's thyroiditis on histopathology was correlated with serologic and sonographic markers. We further assessed the impact of low versus high titers of TPOAb upon this concordance.

RESULTS

Of 825 patients, 277 (33.5%) had histologic confirmation of Hashimoto's thyroiditis, 235 patients (28.4%) had elevated serum levels of TPOAb, and 197 (23.8%) had sonographic evidence of diffuse heterogeneity. Of those with histopathologic evidence, only 64% had elevated TPOAb (sensitivity: 63.9%; specificity: 89.4%), while only 49% were sonographically diffusely heterogeneous (sensitivity: 49.1%; specificity: 88.9%). A subset of only 102 of 277 (37%) with histologically proven Hashimoto's thyroiditis was positive for both TPOAb and diffusely heterogeneous. Concordance analysis demonstrated that TPOAb and histopathology had higher agreement (κ = 0.55) than did ultrasound and histopathology (κ = 0.40) for the diagnosis of Hashimoto's thyroiditis. Higher titers of TPOAb correlated with a higher likelihood of Hashimoto's thyroiditis, with a best cutoff of 2.11-fold the upper normal level of TPOAb.

CONCLUSION

Only moderate concordance exists between serological evidence of Hashimoto's thyroiditis and histopathologic findings, though it increases with higher TPOAb concentration. Diffuse heterogeneity on ultrasound is a less-sensitive diagnostic tool than elevated TPOAb.

Prognostic Significance of Extent of Invasion in Poorly Differentiated Thyroid Carcinoma

Background: The 2017 World Health Organization (WHO) Classification of Tumors of Endocrine Organs defines poorly differentiated thyroid carcinoma (PDTC) as a tumor with conventional criteria of malignancy (capsular penetration or vascular invasion) with solid, insular, or trabecular growth, a lack of nuclear features of papillary thyroid carcinoma, and increased mitotic activity, tumor necrosis, or convoluted nuclei. The extent of invasion has been shown to be prognostic in follicular thyroid carcinoma and Hürthle cell carcinoma. Our aim was to evaluate how extent of invasion impacts clinical outcome for PDTC. Methods: We retrospectively identified 47 consecutively diagnosed cases of PDTC that were resected between 2005 and 2018. All cases were reviewed to confirm that the tumors met the 2017 Endocrine WHO criteria of PDTC. In addition, tumors were categorized as follows: encapsulated with capsular penetration only, encapsulated with focal vascular invasion (fewer than four foci), encapsulated with extensive vascular invasion (four or more foci), or widely invasive. Histopathologic characteristics and clinical outcome data were recorded. Results: A total of 47 cases of PDTC, including 15 oncocytic tumors, were identified from 28 (60%) women and 19 (40%) men (mean age of 57 years at diagnosis). The mean tumor size was 4.3 cm. Mitoses numbered 8 per 10 high-power fields (HPF) on average (range: 1-34), and necrosis was present in 21 (45%) cases. Eight (17%) cases were encapsulated with capsular penetration only, 5 (11%) were encapsulated with focal vascular invasion, 18 (38%) were encapsulated with extensive vascular invasion, and 16 (34%) were widely invasive. Of the 42 (89%) patients with follow-up data, 7 (17%) died of disease (with a mean survival time of 6.4 years), 11 (26%) have distant metastatic disease, and 24 (57%) have no evidence of disease (mean follow-up 5.6 years). Eight (19%) patients presented with M1 disease at diagnosis. The 5-year disease-free survival (DFS) for patients with M0 disease at diagnosis was 100% for patients with tumors with capsular invasion only or focal vascular invasion (n = 7), 73% for patients with encapsulated tumors with extensive vascular invasion (n = 11), and 17% for patients with widely invasive PDTCs (n = 6). DFS estimates by Kaplan-Meier analysis were significantly different between these groups (p = 0.0016). Conclusions: Extent of invasion appears to be an important parameter that affects clinical outcome for patients with PDTC. In our cohort, patients with encapsulated PDTC with capsular invasion only or focal vascular invasion had an excellent outcome.

Thyroid Nodules and Thyroid Cancer in the Pregnant Woman

Thyroid nodules and thyroid cancer are common conditions and may be identified during pregnancy. The comprehensive evaluation of thyroid nodules during pregnancy includes a medical history, physical examination, ultrasound assessment, and (when indicated) an ultrasound-guided fine-needle aspiration biopsy. Most thyroid cancers detected during pregnancy will not grow nor pose significant risk during gestation, and thyroid surgery in pregnant women poses higher risks than in nonpregnant women. Through a balanced and informed approach to the clinical care of this unique population, outcomes can be optimized for both the mother and the fetus.

Association of Thyroid Function Test Abnormalities and Thyroid Autoimmunity With Preterm Birth: A Systematic Review and Meta-analysis

Importance

Maternal hypothyroidism and hyperthyroidism are risk factors for preterm birth. Milder thyroid function test abnormalities and thyroid autoimmunity are more prevalent, but it remains controversial if these are associated with preterm birth.

Objective

To study if maternal thyroid function test abnormalities and thyroid autoimmunity are risk factors for preterm birth.

Data Sources and Study Selection

Studies were identified through a search of the Ovid MEDLINE, EMBASE, Web of Science, the Cochrane Central Register of Controlled Trials, and Google Scholar databases from inception to March 18, 2018, and by publishing open invitations in relevant journals. Data sets from published and unpublished prospective cohort studies with data on thyroid function tests (thyrotropin [often referred to as thyroid-stimulating hormone or TSH] and free thyroxine [FT4] concentrations) or thyroid peroxidase (TPO) antibody measurements and gestational age at birth were screened for eligibility by 2 independent reviewers. Studies in which participants received treatment based on abnormal thyroid function tests were excluded.

Data Extraction and Synthesis

The primary authors provided individual participant data that were analyzed using mixed-effects models.

Main Outcomes and Measures

The primary outcome was preterm birth (<37 weeks' gestational age).

Results

From 2526 published reports, 35 cohorts were invited to participate. After the addition of 5 unpublished data sets, a total of 19 cohorts were included. The study population included 47 045 pregnant women (mean age, 29 years; median gestational age at blood sampling, 12.9 weeks), of whom 1234 (3.1%) had subclinical hypothyroidism (increased thyrotropin concentration with normal FT4 concentration), 904 (2.2%) had isolated hypothyroxinemia (decreased FT4 concentration with normal thyrotropin concentration), and 3043 (7.5%) were TPO antibody positive; 2357 (5.0%) had a preterm birth. The risk of preterm birth was higher for women with subclinical hypothyroidism than euthyroid women (6.1% vs 5.0%, respectively; absolute risk difference, 1.4% [95% CI, 0%-3.2%]; odds ratio [OR], 1.29 [95% CI, 1.01-1.64]). Among women with isolated hypothyroxinemia, the risk of preterm birth was 7.1% vs 5.0% in euthyroid women (absolute risk difference, 2.3% [95% CI, 0.6%-4.5%]; OR, 1.46 [95% CI, 1.12-1.90]). In continuous analyses, each 1-SD higher maternal thyrotropin concentration was associated with a higher risk of preterm birth (absolute risk difference, 0.2% [95% CI, 0%-0.4%] per 1 SD; OR, 1.04 [95% CI, 1.00-1.09] per 1 SD). Thyroid peroxidase antibody-positive women had a higher risk of preterm birth vs TPO antibody-negative women (6.6% vs 4.9%, respectively; absolute risk difference, 1.6% [95% CI, 0.7%-2.8%]; OR, 1.33 [95% CI, 1.15-1.56]).

Conclusions and Relevance

Among pregnant women without overt thyroid disease, subclinical hypothyroidism, isolated hypothyroxinemia, and TPO antibody positivity were significantly associated with higher risk of preterm birth. These results provide insights toward optimizing clinical decision-making strategies that should consider the potential harms and benefits of screening programs and levothyroxine treatment during pregnancy.