Bone metastasis from noninvasive follicular thyroid neoplasm with papillary-like nuclear features (NIFTP); a case report.

BACKGROUND: The term non-invasive follicular thyroid neoplasm with papillary-like nuclear features (NIFTP) was recently proposed as a non-malignant thyroid lesion with indolent behavior that does not require post-operative radio-iodine treatment. We are reporting a case of NIFTP with bone metastasis that is the second case reported so far. CASE PRESENTATION: We describe a 38-year-old woman who presented with an indeterminate thyroid nodule and underwent total thyroidectomy with the finding of NIFTP on careful pathologic examination. However, her initial follow-up evaluation revealed a serum thyroglobulin level of > 300 ng/ml and a diagnostic whole body 131I scan demonstrated a focus of increased uptake in the left hemipelvis, confirmed on CT scan to be a lytic lesion in the left iliac bone. She was treated with 7.4GBq (200 mCi) of 131I and her follow-up 1 year later revealed an undetectable serum thyroglobulin and a negative whole body 131I scan with no visible uptake in the iliac bone indicating an excellent response. CONCLUSION: This case presentation reminds us to be alert to the rare occurrence of distant metastasis in NIFTP and the need for a case by case analysis and continuing post-operative follow-up for detection of residual or recurrent disease.

Comprehensive guidance on the diagnosis and management of primary mesenchymal tumours of the thyroid gland.

Most primary thyroid tumours are of epithelial origin. Primary thyroid mesenchymal tumours are rare but are being increasingly detected. A vast majority of thyroid mesenchymal tumours occur between the fourth and seventh decades of life, presenting as progressively enlarging thyroid nodules that often yield non-diagnostic results or spindle cells on fine needle aspiration biopsy. Surgery is the preferred mode of treatment, with adjuvant chemoradiotherapy used for malignant thyroid mesenchymal tumours. Benign thyroid mesenchymal tumours have excellent prognosis, whereas the outcome of malignant thyroid mesenchymal tumours is variable. Each thyroid mesenchymal tumour is characterised by its unique histopathology and immunohistochemistry. Because of the rarity and aggressive nature of malignant thyroid mesenchymal tumours, a multidisciplinary team-based approach should ideally be used in the management of these tumours. Comprehensive guidelines on the management of thyroid mesenchymal tumours are currently lacking. In this Review, we provide a detailed description of thyroid mesenchymal tumours, their clinical characteristics and tumour behaviour, and provide recommendations for the optimal management of these tumours.

Differentiated thyroid cancer and Hashimoto thyroiditis: Utility of the Afirma gene expression classifier.

BACKGROUND AND OBJECTIVES: The Afirma gene expression classifier (AGEC) has not been tested or validated in a high-risk group, such as patients with Hashimoto's thyroiditis (HT). We hypothesized that AGEC would perform worse in patients with HT. METHODS: A retrospective review of patient charts in a single academic institution who underwent thyroidectomy between 2012 and 2017 was conducted. Patients with HT who underwent AGEC were identified to calculate sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV). RESULTS: We identified 69 patients with HT and atypia of undetermined significance/follicular lesion of undetermined significance (AUS/FLUS) on cytology who underwent AGEC analysis. The mean age of AGEC cohort was 50 years (range, 26-77 years) with 90% female. The median nodule size was 1.9 cm (interquartile range [IQR], 1.2-2.7 cm). Of the 69 patients, 62 showed suspicious AGEC of which 26 showed TC on surgical pathology. Of the seven benign AGEC, two showed TC on surgical pathology. The sensitivity, specificity, PPV, and NPV were 93%, 12%, 42%, and 71%, respectively. Of the entire AGEC cohort, 17 (43%) showed multicentric disease. CONCLUSIONS: We observed a lower NPV for AGEC to rule out thyroid cancer in patients with HT, which reduces the utility of the test for this population.

Poor patient compliance with instructions for continuous sialogogues after 131 I therapy.

OBJECTIVES: To analyze the role of patient compliance as a factor in evaluating the effectiveness of continuous sialogogues to prevent salivary side effects from 131 I therapy in differentiated thyroid cancer patients. METHODS: Differentiated thyroid cancer patients who were clinically scheduled for an 131 I therapy at MedStar Washington Hospital Center between 2012 and 2013 were given instructions for continuous sialogogues per standard clinical protocol. The prospective survey was given at multiple time points. RESULTS: Ninety-nine patients consented to participate of whom 94 participants had complete data. The mean prescribed 131 I activity was 121 ± 50 mCi (4.5 ± 1.9 GBq), range 27.5-288 mCi (1.0-10.7 GBq ). Overall, only 10% (9/94) of patients were compliant with continuous sialogogues. Even though all patients took sialogogues on the first day of post-therapy, 17% of participants did not continuously take sialogogues during the first day, 60% during the first night, and 72% on the second day despite rigorous instructions to continue for two days. CONCLUSION: Despite repetitive instructions to use sialogogues continuously, most patients (90%) were not compliant. In future studies, strict monitoring and evaluation of patient compliance will be crucial when assessing the effect of continuous versus intermittent or delayed initiation of sialogogues.

The effect of lithium on the progression-free and overall survival in patients with metastatic differentiated thyroid cancer undergoing radioactive iodine therapy.

OBJECTIVE: Pretreatment with lithium (Li) is associated with an increased residence time of radioactive iodine (RAI) in differentiated thyroid cancer (DTC) metastases. There are no data translating this observation into long-term outcomes. The study goal was to compare the efficacy of three methods of preparation for RAI therapy in metastatic DTC-thyroid hormone withdrawal (THW), THW with pretreatment with Li (THW+Li), and recombinant human TSH (rhTSH). DESIGN/PATIENTS/MEASUREMENTS: We performed a cohort study comparing overall survival (OS) and progression-free survival (PFS) between the three groups: THW (n = 52), THW+Li (n = 41) and rhTSH (n = 42). Kaplan-Meier analyses were performed to compare OS and PFS between the groups. Cox proportional hazards regression model with a stepwise variable selection was performed to study the contribution of age, gender, histology, TNM status, a location of distant metastases and RAI dose. RESULTS: During the follow-up of median 5.1 (IQR = 3.0-8.1) years, 52% of patients had disease progression and 12.6% died. Although THW+Li group was characterized by the longest OS (P = 0.007), only age (HR 1.05, CI 1.01-1.09, P = 0.01) and widespread disease (HR 3.8, CI 1.2-11.8, P = 0.02) were found to affect OS in a multivariate model. There was no difference in PFS between the groups (P = 0.47). Presence of distant metastases limited to the lungs only was associated with longer PFS (PFS HR 0.35, CI 0.20-0.60, P = 0.0002). CONCLUSION: The older age is associated with shorter OS, while disease burden affects OS and PFS in patients with metastatic thyroid cancer. The method of preparation for RAI therapy does not affect the outcome.

18F-FDG-PET SUV AS A PROGNOSTIC MARKER OF INCREASING SIZE IN THYROID CANCER TUMORS.

OBJECTIVE: Positron emission tomography/computed tomography (PET/CT) scans with 2-[fluorine-18] fluoro-2-deoxy-D-glucose (18F-FDG) are used in high-risk thyroid cancer patients to identify metastasis. The prognostic significance of increases in standardized uptake values (SUVs) has not been clearly defined. This pilot study investigated the correlation between SUV increases and subsequent changes in individual lesion size. METHODS: A retrospective chart review of patients with histologically confirmed thyroid cancer who were monitored with serial 18F-FDG-PET/CT scans from 2008 to 2013 was performed. Forty-seven patients were selected for analysis. A mixed-effects statistical model was used after data normalization. RESULTS: For a 10% increase in SUV, a 6% increase in tumor area was observed (P<.0001). Analysis on cube root-transformed data from serial scans was significant in 4 of 5 groups: scans 1 to 2 (P = .0001), scans 2 to 3 (P = .0005), scans 3 to 4 (P = .008), scans 4 to 5 (P = .66), and overall (P<.0001). After exclusion of outliers, for a 10% increase in SUV, the expected percentage increases in area on subsequent scans were found to be 3.4% (P = .0006), 2.6% (P = .005), 4% (P = .074), and 4.1% (P = .27) for the second, third, fourth, and fifth scans, respectively. The association was similarly significant in cases with a ≥25% increase in SUV. Secondary analysis showed a significant association of SUV with thyroglobulin (Tg) level (P = .035) but not with thyroid-stimulating hormone (TSH) level (P = .85). CONCLUSIONS: A significant positive correlation was noted between the increase in lesional SUV and subsequent increase in lesion area. An increase in lesional SUV in subsequent scans may portend tumor growth and could prompt consideration for earlier or more aggressive intervention. ABBREVIATIONS: DTC = differentiated thyroid cancer EORTC = European Organization for Research and Treatment of Cancer 18F-FDG = 2-[fluorine-18] fluoro-2-deoxy-D-glucose FNA = fine-needle aspiration MTC = medullary thyroid cancer PET/CT = positron emission tomography/computed tomography PVE = partial volume effect RAI = radioactive iodine SUV = standardized uptake value Tg = thyroglobulin TSH = thyroid-stimulating hormone.

[Myxedema coma]. / Coma mixedematoso.

Hypothyroidism is a frequently diagnosed and simply treated disease. If not recognised, however, in time it may develop into the most severe manifestation of hypothyroidism known as myxedema coma. The term "myxedema coma" is generally seen as misleading since most patients do not initially present in a coma. The typical progression is lethargy evolving into stupor and, eventually, into coma with respiratory failure and hypothermia. It mainly affects elderly women, often occurring in winter and is relatively rare. It can be considered a form of decompensated hypothyroidism often triggered by a variety of non-thyroid conditions or diseases provoking an extremely severe condition of multiple system failure with lethal consequences unless an early diagnosis is made and an aggressive treatment is administered.

A diagnostic scoring system for myxedema coma.

OBJECTIVE: To develop diagnostic criteria for myxedema coma (MC), a decompensated state of extreme hypothyroidism with a high mortality rate if untreated, in order to facilitate its early recognition and treatment. METHODS: The frequencies of characteristics associated with MC were assessed retrospectively in patients from our institutions in order to derive a semiquantitative diagnostic point scale that was further applied on selected patients whose data were retrieved from the literature. Logistic regression analysis was used to test the predictive power of the score. Receiver operating characteristic (ROC) curve analysis was performed to test the discriminative power of the score. RESULTS: Of the 21 patients examined, 7 were reclassified as not having MC (non-MC), and they were used as controls. The scoring system included a composite of alterations of thermoregulatory, central nervous, cardiovascular, gastrointestinal, and metabolic systems, and presence or absence of a precipitating event. All 14 of our MC patients had a score of ≥60, whereas 6 of 7 non-MC patients had scores of 25 to 50. A total of 16 of 22 MC patients whose data were retrieved from the literature had a score ≥60, and 6 of 22 of these patients scored between 45 and 55. The odds ratio per each score unit increase as a continuum was 1.09 (95% confidence interval [CI], 1.01 to 1.16; P = .019); a score of 60 identified coma, with an odds ratio of 1.22. The area under the ROC curve was 0.88 (95% CI, 0.65 to 1.00), and the score of 60 had 100% sensitivity and 85.71% specificity. CONCLUSION: A score ≥60 in the proposed scoring system is potentially diagnostic for MC, whereas scores between 45 and 59 could classify patients at risk for MC.

Sex-Specific Expression of Histone Lysine Demethylases (KDMs) in Thyroid Cancer.

BACKGROUND: The incidence of thyroid cancer in women is 3-4-fold higher than in men. To characterize sex-specific molecular alterations in thyroid cancer, we examined the expression of sex-biased genes in normal thyroids and thyroid tumors. METHODS: Ingenuity pathways analysis was used to define sex-biased gene networks using data from the Cancer Genome Atlas (TCGA). Confirmatory studies were performed through the analysis of histone lysine demethylases (KDMs) expression by real-time PCR and immunostaining. RESULTS: In normal thyroids, 44 sex-biased genes were comparatively upregulated in male and 28 in female patients. The expressions of 37/72 (51%) sex-biased genes were affected in cancer tissues compared with normal thyroids. Gene network analyses revealed sex-specific patterns in the expressions of KDM5C, KDM5D, and KDM6A. In confirmatory studies, KDM5D mRNA and protein were detected only in males, whereas KDM5C and KDM6A were detected in samples from male and female patients. Nuclear staining with anti-KDMs was found in normal thyroids, but a loss of nuclear expression with a concomitant gain of cytoplasmic staining was observed in cancer tissues. CONCLUSIONS: Normal thyroids have a sex-specific molecular signature, and the development of thyroid cancer is associated with a differential expression of sex-biased genes. The sex-specific expression of KDMs, coupled with cancer-related alterations in their intracellular localization, may contribute to mechanisms underlying sex differences in thyroid tumorigenesis.

Association of Free Thyroxine with Progression-Free Survival in Intermediate and High Risk Differentiated Thyroid Cancer.

CONTEXT: Supraphysiologic thyroxine (T4) doses are used in intermediate and high-risk patients with differentiated thyroid cancer (IR/HR-DTC) to suppress tumor progression by thyrotropin (TSH). However, preclinical data suggest that T4 can also act as a growth stimulus for cancer, but there is no clinical evidence supporting this claim. OBJECTIVE: We analyzed the association between free T4 (FT4) and progression-free survival (PFS) in patients with IR/HR-DTC. METHODS: This longitudinal cohort study, approved by multi-institutional review board, included patients with IR/HR-DTC treated uniformly with total thyroidectomy, radioiodine (RAI), and TSH suppression therapy, with at least three TSH and FT4 values available. Association between FT4 and PFS at landmarks 6, 12, and 18 months was assessed by Kaplan-Meier survival curves, while competing risks were assessed through Cox proportional hazards model. RESULTS: From 739 screened patients 382 met the inclusion criteria and were characterized by a median age of 46 (34-59) years, 64.1% women, treated with a median RAI dosage of 159 (110-410) mCi. During follow up of 7.1 (3.4-12.7) years 34.6% experienced disease progression.Elevated FT4, observed in 29.3% of patients, was not associated with worse PFS (HR 0.9, CI 0.54-1.5, p=0.69), while age (HR 1.02, CI 1.004-1.04, p=0.01), tumor size (HR 1.15, CI 1.04-1.28, p=0.01), and metastases to the lateral neck lymph nodes (HR 2.9, CI 1.7-4.74, p<0.001), bones (HR 4.87, CI 1.79-13.3, p=0.002), and brain (HR 5.56, CI 2.54-12.2, p<0.001) were associated with shorter PFS. CONCLUSIONS: Contrary to preclinical evidence, elevated FT4 levels do not affect PFS in patients with IR/HR-DTC.

Improved sexual function after parathyroidectomy in women with primary hyperparathyroidism.

BACKGROUND: The study aimed to evaluate whether women with primary hyperparathyroidism (PHPT) experience improvement in their sexual function after parathyroidectomy. METHODS: Women with PHPT or benign thyroid nodules (controls) undergoing surgery were administered the validated Parathyroidectomy Assessment Score (PAS), Patient-Reported Outcomes Measurement Information System-29 (PROMIS-29) and Female Sexual Function Index (FSFI) pre-operatively, at 3 months and 6 months postoperatively. RESULTS: Of the 26 PHPT and 18 control patients, PHPT patients were older (53.1 vs 45.3 years, p â€‹= â€‹0.008). Post-operatively, both PHPT (pre-op 2.4 vs 3-month 3.0 vs 6-month 2.4, p â€‹= â€‹0.022) and control patients (pre-operative 2.4 vs 3-month 3.3 vs 6-month 3.6, p â€‹= â€‹0.032) reported increased desire for sexual activities. In addition, PHPT patients experienced increased arousal (pre-operative 2.7 vs 3-month 3.9 vs 6-month 3.6, p â€‹= â€‹0.047) and satisfaction (pre-operative 3.0 vs 3-month 4.8 vs 6-month 4.0, p â€‹= â€‹0.006). CONCLUSIONS: The current study indicates that women with PHPT may experience improved sexual function after parathyroidectomy.

Efficacy of machine learning to identify clinical factors influencing levothyroxine dosage after total thyroidectomy.

BACKGROUND: We employed Machine Learning (ML) to evaluate potential additional clinical factors influencing replacement dosage requirements of levothyroxine. METHOD: This was a retrospective study of patients who underwent total or completion thyroidectomy with benign pathology. Patients who achieved an euthyroid state were included in three different ML models. RESULTS: Of the 487 patients included, mean age was 54.1 ± 14.1 years, 86.0% were females, 39.0% were White, 53.0% Black, 2.7% Hispanic, 1.4% Asian, and 3.9% Other. The Extreme Gradient Boosting (XGBoost) model achieved the highest accuracy at 61.0% in predicting adequate dosage compared to 47.0% based on 1.6 mcg/kg/day (p < 0.05). The Poisson regression indicated non-Caucasian race (p < 0.05), routine alcohol use (estimate = 0.03, p = 0.02), and osteoarthritis (estimate = -0.10, p < 0.001) in addition to known factors such as age (estimate = -0.003, p < 0.001), sex (female, estimate = -0.06, p < 0.001), and weight (estimate = 0.01, p < 0.001) were associated with the dosing of levothyroxine. CONCLUSIONS: Along with weight, sex, age, and BMI, ML algorithms indicated that race, ethnicity, lifestyle and comorbidity factors also may impact levothyroxine dosing in post-thyroidectomy patients with benign conditions.

Efficacy of Levothyroxine Sodium Soft Gelatin Capsules in Thyroidectomized Patients Taking Proton Pump Inhibitors: An Open-Label Study.

Background: Treatment with proton pump inhibitors (PPIs) and antacids affects the gastrointestinal absorption of levothyroxine sodium (LT4) tablets. Patients with hypothyroidism taking LT4 and PPIs or antacids, thus, require appropriate monitoring. The objective of this study was to determine whether a soft gelatin capsule of LT4 (Tirosint®) would obviate the effect of PPIs on LT4 absorption. The objective was achieved by assessing the effects of a switch from a conventional LT4 tablet form to the same dose as soft capsules in thyroidectomized patients on treatment with LT4 and PPIs. Methods: Patients with history of hypothyroidism due to total thyroidectomy on stable treatment with LT4 tablets, and with gastrointestinal disease treated with PPIs, were switched to a 12-week treatment with Tirosint at the same dose of the LT4 tablets, while maintaining treatment with PPIs. Serum thyrotropin (TSH) levels were the primary endpoint of the study. Secondary efficacy endpoints were: serum levels of free thyroxine (fT4), total thyroxine (TT4), free triiodothyronine (fT3), total triiodothyronine (TT3), creatine-phosphokinase (CPK), sex-hormone binding globulin, ferritin, angiotensin converting enzyme, and a lipid panel. Results: Forty-seven patients (36 females and 11 males, mean age 55.4 years) were enrolled and 45 of them completed the study (2 patients withdrew consent). During treatment with Tirosint, mean TSH levels demonstrated a statistically significant decrease (mean changes from baseline: -0.32 mIU/L at week 6 and -0.68 mIU/L at week 12) and concomitant increases in thyroid hormone (TH) levels from baseline to week 12, which were statistically significant for fT3 and TT3 (mean changes from baseline: 0.26 pmol/L and 0.10 nmol/L, respectively). Significant decreases of serum low-density lipoprotein, total cholesterol, and CPK levels were observed at week 12. No signs/symptoms arose during the study that could be specifically correlated to either hypo- or hyperthyroidism. Conclusions: In thyroidectomized patients taking PPIs and replacement LT4, a switch from conventional LT4 tablets to LT4 soft capsules at the same dose was associated with a significant decrease in TSH and increase in TH, indicating that LT4 absorption may be less affected by PPIs when given in the form of soft capsules. Clinical Trial Registration: NCT03094416.

Hashimoto thyroiditis: an evidence-based guide to etiology, diagnosis and treatment.

Hashimoto thyroiditis (HT) is a common autoimmune disorder, affecting women 7-10 times more often than men, that develops because of genetic susceptibility, Xchromosome inactivation patterns modulated by environmental factors as well as microbiome composition, and leads to an imbalance in self­tolerance mechanisms. The consequential thyroid infiltration by lymphocytes, potentiated by antibody­mediated autoimmune response through the antibodies against thyroid peroxidase (TPOAbs), leads to a destruction of thyrocytes. The presence of TPOAbs is associated with a 2 to 4­fold increase in the risk of recurrent miscarriages and preterm birth in pregnant women. The clinical presentation of HT includes: (A) thyrotoxicosis, when stored thyroid hormones are released to circulation from destroyed thyroid follicles; (B) euthyroidism, when preserved thyroid tissue compensates for destroyed thyrocytes; and (C) hypothyroidism, when thyroid hormone production by the affected thyroid gland is insufficient. The management of Hashitoxicosis is based on symptoms control usually with ß­blockers, euthyroidism requires periodical thyroid stimulating hormone measurements to assess for progression to hypothyroidism, and hypothyroidism is treated with thyroid hormone replacement therapy. The dose of levothyroxine (LT4) used for treatment is based on the degree of preserved thyroid functionality and lean body mass, and usually ranges from 1.4 to 1.8 mcg/kg/day. There is insufficient evidence to recommend for or against therapy with triiodothyronine (T3), apart from in pregnancy when only levothyroxine is indicated, as T3 does not sufficiently cross fetal blood­brain barrier. HT is associated with 1.6 times higher risk of papillary thyroid cancer and 60 times higher risk of thyroid lymphoma than in general the population.

Sex Differences in Differentiated Thyroid Cancer.

Background: Sex dimorphism strongly impacts tumor biology, with most cancers having a male predominance. Uniquely, thyroid cancer (TC) is the only nonreproductive cancer with striking female predominance with three- to four-fold higher incidence among females, although males generally have more aggressive disease. The molecular basis for this observation is not known, and current approaches in treatment and surveillance are not sex specific. Summary: Although TC has overall good prognosis, 6-20% of patients develop regional or distant metastasis, one third of whom are not responsive to conventional treatment approaches and suffer a 10-year survival rate of only 10%. More efficacious treatment strategies are needed for these aggressive TCs, as tyrosine kinase inhibitors and immunotherapy have major toxicities without demonstrable overall survival benefit. Emerging evidence indicates a role of sex hormones, genetics, and the immune system in modulation of both risk for TC and its progression in a sex-specific manner. Conclusion: Greater understanding of the molecular mechanisms underlying sex differences in TC pathogenesis could provide insights into the development of sex-specific, targeted, and effective strategies for prevention, diagnosis, and management. This review summarizes emerging evidence for the importance of sex in the pathogenesis, progression, and response to treatment in differentiated TC with emphasis on the role of sex hormones, genetics, and the immune system.

Comparing the rate and extent of malignancy in surgically excised thyroid nodules across race and ethnicity.

BACKGROUND: Few studies have compared the features of thyroid cancer among races and ethnicities. We hypothesized that race and ethnicity may influence the frequency and features of thyroid malignancy in thyroid nodules. METHOD: This was a retrospective chart review of patients between 2013 and 2020 who underwent thyroidectomy. RESULTS: In the analysis of 2737 patients, thyroid cancer was less prevalent among Blacks (24.0% vs Whites 52.1%, Hispanics 58.7%, Asians 71.7%, and Others 57.9%, p < 0.001). Thyroid cancer in Blacks was less likely to have extrathyroidal extension (9.7% vs Whites 18.6%, Hispanics 25.8%, Asians 18.2%, and Others 17.8%, p = 0.01), overall nodal involvement (12.4% vs Whites 31.1%, Hispanics 37.5%, Asians 36.3%, and Others 30.1%, p < 0.01), and lateral neck metastasis (4.4% vs Whites 10.8%, Hispanics 6.3%, Asians 13.2%, and Others 9.6%, p = 0.02). CONCLUSIONS: Race and ethnicity may play important roles in the risk of malignancy as well as in the extent of thyroid cancer.

Clinical Factors Predictive of Lymph Node Metastasis in Thyroid Cancer Patients: A Multivariate Analysis.

BACKGROUND: Early-stage thyroid cancers have excellent survival. However, lymph node metastases (LNM) confer a worse prognosis and are not always known preoperatively. Therefore, investigation on the clinical and histological factors predictive of LNM in thyroid cancers was conducted to tailor the extent of surgery and radioactive iodine therapy. STUDY DESIGN: Multivariate logistic regressions were performed based on retrospective data from thyroid cancer patients seen between 2013 and 2020 at a single institution. RESULTS: Among 913 patients, mean age was 49.4 years, 76.5% were female, 58.3% were White, 21.2% were Black, and 27.9% had LNM. In the multivariate analyses in which the outcome was LNM, White (odds ratio [OR] 1.74, 95% CI 0.98 to 3.15, p = 0.064) and Hispanic patients (OR 2.36, 95% CI 0.97 to 5.77, p = 0.059) trended toward higher risk of LNM compared to Black patients, whereas age (OR 0.98, 95% CI 0.97 to 1.00, p = 0.008) showed protective effect. Tumor size (OR 1.04, 95% CI 1.01 to 1.07, p = 0.007), extrathyroidal extension (OR 2.46, 95% CI 1.53 to 3.97, p < 0.001), lymphovascular invasion (OR 6.30, 95% CI 3.68 to 11.14, p < 0.001), and multifocality (OR 1.47, 95% CI 1.01 to 2.12, p = 0.042) were associated with higher risk of LNM. In another model with outcome as >5 LNM, tumor size (OR 1.07, 95% CI 1.03 to 1.11, p = 0.001), age (OR 0.95, 95% CI 0.93 to 0.97, p < 0.001), extrathyroidal extension (OR 3.20, 95% CI 1.83 to 5.61, p < 0.001), and lymphovascular invasion (OR 6.82, 95% CI 3.87 to 12.17, p < 0.001) remained significant predictors. CONCLUSION: Our analyses demonstrated and confirmed that age, tumor size, extrathyroidal extension, and lymphovascular invasion are independent predictors of significant LNM, thereby conferring higher risk of recurrence. Risk of LNM based on these patient characteristics should be considered when planning an operative approach.

Metastatic Differentiated Thyroid Cancer Survival Is Unaffected by Mode of Preparation for 131I Administration.

Context: Recombinant human thyrotropin (rhTSH) is currently not Food and Drug Administration approved for the treatment of high-risk patients with differentiated thyroid cancer (DTC). Objective: The goal of our study was to compare the outcomes in higher-risk patients with metastatic DTC prepared for radioiodine (RAI) therapy with rhTSH vs thyroid hormone withdrawal (THW). Methods: A retrospective chart review was performed of patients with metastatic DTC in follow-up at MedStar Washington Hospital Center and MedStar Georgetown University Hospital from 2009 to 2017. Patients were divided according to their preparation for RAI therapy, with assessment of progression-free survival (PFS) and overall survival (OS). Results: Fifty-five patients with distant metastases (16 men, 39 women) were prepared for RAI therapy exclusively either with rhTSH (n = 27) or with THW (n = 28). There were no statistically significant differences between the groups regarding clinicopathological features and history of RAI therapies. The median follow-up time for patients with rhTSH-aided therapies was 4.2 years (range, 3.3-5.5 years) and for patients with THW-aided therapies was 6.8 years (range, 4.2-11.6 years) (P = .002). Multivariate analysis showed that the method of thyrotropin stimulation was not associated with a difference in PFS or OS. Conclusion: As has been shown previously for low-risk DTC, this study indicates that the mode of preparation for RAI therapy does not appear to influence the outcomes of patients with metastatic DTC. PFS and OS were similar for patients with THW-aided or rhTSH-aided RAI therapies.