Expression of the Calcium-Sensing Receptor on Normal and Abnormal Parathyroid and Thyroid Tissue.

INTRODUCTION: Current imaging techniques have several limitations in detecting parathyroid glands. We have investigated the calcium-sensing receptor (CaSR) as a potential target for specifically labeling parathyroid glands for radiologic detection. For accurate imaging it is vital that a large differential expression exists between the target tissue and adjacent structures. We sought to investigate the relative abundance of the CaSR in normal and abnormal parathyroid tissue, as well as normal and abnormal thyroid. METHODS: Existing clinical specimens were selected that represented a wide variety of pathologically and clinically confirmed malignant and benign thyroid and parathyroid specimens. Sections were stained for the CaSR using immunohistochemistry and scored for intensity and abundance of expression. (H score = intensity scored from 0 to 3 multiplied by the % of cells at each intensity. Range 0-300). RESULTS: All parathyroid specimens expressed the CaSR to a high degree. Normal parathyroid had the highest H score (271, s.d. 25.4). Abnormal parathyroid specimens were slightly lower but still much higher than normal thyroid (H score 38.3, s.d. 23.3). Medullary thyroid cancer also expressed the CaSR significantly higher than normal thyroid (H score 182, s.d. 69.1, P < 0.001) but below parathyroid levels. Hürthle cell carcinoma expressed the CaSR to a lesser degree but higher than normal thyroid (H score 101, s.d. 46.4, P = 0.0037). CONCLUSIONS: The CaSR is differentially expressed on parathyroid tissue making it a feasible target for parathyroid imaging. False positives might be anticipated with medullary and Hürthle cell cancers.

Update on Pheochromocytoma and Paraganglioma from the SSO Endocrine/Head and Neck Disease-Site Work Group. Part 1 of 2: Advances in Pathogenesis and Diagnosis of Pheochromocytoma and Paraganglioma.

This first part of a two-part review of pheochromocytoma and paragangliomas (PPGLs) addresses clinical presentation, diagnosis, management, treatment, and outcomes. In this first part, the epidemiology, prevalence, genetic etiology, clinical presentation, and biochemical and radiologic workup are discussed. In particular, recent advances in the genetics underlying PPGLs and the recommendation for genetic testing of all patients with PPGL are emphasized. Finally, the newer imaging methods for evaluating of PPGLs are discussed and highlighted.

Update on Pheochromocytoma and Paraganglioma from the SSO Endocrine and Head and Neck Disease Site Working Group, Part 2 of 2: Perioperative Management and Outcomes of Pheochromocytoma and Paraganglioma.

This is the second part of a two-part review on pheochromocytoma and paragangliomas (PPGLs). In this part, perioperative management, including preoperative preparation, intraoperative, and postoperative interventions are reviewed. Current data on outcomes following resection are presented, including outcomes after cortical-sparing adrenalectomy for bilateral adrenal disease. In addition, pathological features of malignancy, surveillance considerations, and the management of advanced disease are also discussed.

Chronic Fatigue After Thyroidectomy: A Patient-Centered Survey.

BACKGROUND: Fatigue after thyroidectomy is common, but there is a paucity of data regarding its prevalence and duration. We hypothesized that total thyroidectomy (TT) patients would have more long-term fatigue than thyroid lobectomy (TL) patients. METHODS: Statewide survey of thyroidectomy patients (2004-2017) was carried out. RESULTS: 281 patients completed the survey. 216 respondents (77%) had TT and 65 (23%) had TL. Within one year of surgery, 172 (61%) respondents recalled being troubled by new fatigue all, most, or some of the time. Total thyroidectomy patients were more likely to report new fatigue (69% vs. 44%, aOR 2.72, 95% CI 1.44 to 5.18). Of patients (n = 172) reporting new fatigue, 67 (39%) reported at least moderate improvement. Nineteen (28%) saw improvement within 1 year, 35 (52%) saw improvement in 1-2 years, and 11 (16%) saw improvement after 2 years. CONCLUSION: Long-term fatigue after TT can be debilitating, long-lasting, and less prevalent after TL.

Use and disparities in parathyroidectomy for symptomatic primary hyperparathyroidism in the Medicare population.

BACKGROUND: Few studies assess use of parathyroidectomy among older adults with symptomatic primary hyperparathyroidism. Our objective was to determine national usage and disparities in parathyroidectomy for symptomatic primary hyperparathyroidism among insured older adults. METHODS: We identified older adult patients with symptomatic primary hyperparathyroidism using Medicare claims (2006-2017). Primary study variables were race/ethnicity, rurality, and zip-code socioeconomic status. We calculated cumulative incidence of parathyroidectomy and used multivariable Cox proportional hazards regression models to assess the adjusted association of our study variables with parathyroidectomy. RESULTS: We included 94,803 patients. The median age at primary hyperparathyroidism diagnosis was 76 years (interquartile range 71-82). The majority of patients were female (72%), non-Hispanic White (82%), from metropolitan areas (82%), and had a Charlson Comorbidity score ≥3 (62%). Nine percent of patients (n = 8,251) underwent parathyroidectomy during follow-up. After adjustment, non-Hispanic Black patients, compared to non-Hispanic White (hazard ratio 0.80; 95% confidence interval 0.74, 0.87), and living in a low socioeconomic status neighborhood (low socioeconomic status vs highest socioeconomic status hazard ratio 0.89; 95% confidence interval 0.83, 0.95) were both associated with lower incidences of parathyroidectomy. Patients from non-metropolitan areas were more likely to undergo parathyroidectomy. CONCLUSION: Parathyroidectomy is underused for symptomatic primary hyperparathyroidism in older adults. Quality improvement efforts, rooted in equitable care, should be undertaken to increase access to parathyroidectomy for this disease.

ACR Appropriateness Criteria® Parathyroid Adenoma.

Hyperparathyroidism is defined as excessive parathyroid hormone production. The diagnosis is made through biochemical testing, in which imaging has no role. However, imaging is appropriate for preoperative parathyroid gland localization with the intent of surgical cure. Imaging is particularly useful in the setting of primary hyperparathyroidism whereby accurate localization of a single parathyroid adenoma can facilitate minimally invasive parathyroidectomy. Imaging can also be useful to localize ectopic or supernumerary parathyroid glands and detail anatomy, which may impact surgery. This document summarizes the literature and provides imaging recommendations for hyperparathyroidism including primary hyperparathyroidism, recurrent or persistent primary hyperparathyroidism after parathyroid surgery, secondary hyperparathyroidism, and tertiary hyperparathyroidism. Recommendations include ultrasound, CT neck without and with contrast, and nuclear medicine parathyroid scans. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

ACB-PCR quantification of K-RAS codon 12 GAT and GTT mutant fraction in colon tumor and non-tumor tissue.

K-RAS mutation is being developed as a cancer biomarker and tumor K-RAS is being used to predict therapeutic response. Yet, levels of K-RAS mutation in normal and pathological tissue samples have not been determined rigorously, nor inter-individual variation in these levels characterized. Therefore, K-RAS codon 12 GAT and GTT mutant fractions were measured in colonic mucosa of individuals without colon cancer, tumor-distal mucosa, tumor-proximal mucosa, normal tumor-adjacent tissues, colonic adenomas, and carcinomas. The results indicate K-RAS codon 12 GAT mutation is present at measurable levels in normal appearing mucosa. All tumors carried K-RAS mutation, in most cases as a mutant subpopulation.

Assessing the efficacy of the fundamentals of research and career development course overseas.

BACKGROUND: As the Fundamentals of Research and Career Development Course (FRCDC) is conducted internationally, questions have arisen regarding the cultural appropriateness of the United States (US) course. We therefore assessed the US-based teaching methodology during the FRCDC in Abuja, Nigeria. We hypothesized that the US-based instructional methods would be effective. METHODS: Twenty questions were distributed to attendees of the FRCDC prior to commencement. The same 20 questions were administered at the conclusion of the course after random reordering. Differences between the pre- and post-test results were assessed for normalcy and compared using the paired t-test. RESULTS: There were 89 attendees, of whom 60 completed the pre-test and 77 completed the post-test. The pre-test group answered 12.3 ± 2.6 questions correctly, which improved to 15.0 ± 2.6 in the post-test group (P < 0.001). On the pre-test, the least common correct answers were for questions regarding type 1 and 2 error (16.7% correct), the definition of health services and outcomes research (26.7%), and how to best address missing data (26.7%). On the post-test, the questions with the least common correct answers were regarding the definition of health services and outcomes research (35%), and the components of an NIH grant (37.7%). CONCLUSIONS: Our results suggest that the FRCDC in Nigeria as given by US faculty has short-term efficacy. Attendees were able to improve their scores despite the cultural differences between them and the lecturers. Our next goal will be to demonstrate long-term efficacy at future courses in the region using similar questionnaire strategies.

Outcome of radioiodine therapy in thyroid cancer patients with recent contrasted computed tomography.

OBJECTIVE: To document the outcome of radioiodine therapy (RIT) in differentiated thyroid cancer (DTC) patients with recent contrasted computed tomography (CCT). METHODS: Eighteen patients with DTC and recent thyroidectomy who underwent RIT within 90 days after a CCT were included. Disease status following RIT and whether the expected response to RIT was achieved were documented. Disease status was classified into one of three categories based on the patient's thyroglobuline level, radioiodine scan (RIS), and other imaging modalities: no evidence of disease (NED), microscopic residual disease (MRD), or gross residual disease (GRD). Expected response to RIT was based on the overall interpretation of the referring physicians of follow up thyroglobuline values, RIS findings and clinical assessment as reflected in progress notes. Follow-up stimulated thyroglobuline and (or) RIS was performed on average 10.8 months after RIT (median 12 months). The last progress note reviewed was on average 33.3 months after RIT (median 31 months). RESULTS: There were 12 patients with NED, two with MRD and four with GRD. Expected response to RIT was achieved in 17 patients. In one patient, the effectiveness of RIT could not be determined. CONCLUSION: RIT in postthyroidectomy setting can be successfully performed within 90 days after CCT. Further research is needed to confirm our findings.

Practical Guide to Quality Control in Surgical Trials.

This Guide to Statistics and Methods outlines the elements of clinical trial quality control that are important to safeguarding data integrity and addressing the unique challenges of procedural trials.

Considerations in incorporating office-based ultrasound of the head and neck.

OBJECTIVE: The purpose of this study was to determine the cost considerations and strategies for incorporating ultrasound (US) in a head and neck practice. STUDY DESIGN AND SETTING: A retrospective chart review of office-based US procedures from 2001 to 2005 was completed at our academic medical center. Billing and coding for US and US guided fine needle aspiration (USFNA) were examined. RESULTS: The appropriate CPT codes are 76536 for US and 76942 and 10022 for USFNA-related procedures. The USFNA codes should be used repeatedly for correct coding of biopsies from multiple sites. Cost (equipment) sharing between specialties is a potential strategy for office-based US incorporation. CONCLUSION: Based on practice volume, specific CPT coding, and Medicare reimbursements, office-based US equipment and certification costs could be offset in 1 year. SIGNIFICANCE: Office-based US can be readily incorporated with significant benefits to patients. Billing and usage strategies were identified that would improve the economics of providing office-based US.

Direct phosphorylation of proliferative and survival pathway proteins by RET.

BACKGROUND: Gain-of-function mutations in the RET tyrosine kinase receptor cause the multiple endocrine neoplasia syndromes type 2a and 2b, and medullary thyroid cancer. We have previously shown that RET signals through focal adhesion kinase (FAK) in medullary thyroid cancer cells and that extracellular signal-regulated kinase (ERK) activity can be blocked by pp2, an inhibitor of both Src and RET. We hypothesized that RET could directly phosphorylate FAK and ERK. METHODS: RET and ERK kinase activity were measured with the use of an in vitro kinase assay. The relative contribution of RET in phosphorylation of ERK was tested by treating cells with PD98059, an inhibitor of MEK, and the RET inhibitor PP2, then measuring ERK activity. RESULTS: Immunoprecipitated, mutant RET from cells or the recombinant RET kinase domain was able to directly phosphorylate tyrosine residues on FAK. Specifically Y576/577, Y861, and Y925, but not the autophosphorylation site Y397 of FAK, were phosphorylated by RET. Similarly ERK 2 could be phosphorylated at Y187 (Y204 in ERK1). Inhibition of both MEK (upstream of ERK) and RET was more potent than inhibition of either alone in decreasing ERK activity. Furthermore, tyrosine residues in DOK1, the p85 subunit of phosphatidylinositol 3' kinase, JNK 1 and 2, P-38, and phospholipase-gamma were directly phosphorylated by RET. CONCLUSIONS: RET directly phosphorylates tyrosine residues on FAK, ERK 1/2, DOK1, the p85 subunit of of phosphatidylinositol 3' kinase, JNK 1 and 2, P-38, and phospholipase-gamma. These data indicate a direct interaction between RET and a broad range of effector molecules that may contribute to tumor pathogenesis.

Use of BRAF v600e immunocytochemistry on FNA direct smears of papillary thyroid carcinoma.

BACKGROUND: Mutations of v-Raf murine sarcoma viral oncogene homolog B1 (BRAF) are identified in almost half of all papillary thyroid carcinomas (PTCs). These mutations are specific for PTC and may confer a worse prognosis. An immunohistochemical (IHC) stain for BRAF is commercially available and has been validated in surgical specimens. Fine-needle aspiration (FNA) is frequently used as a diagnostic tool for risk stratification of thyroid nodules. Therefore, the authors evaluated the performance of immunostaining with the anti-BRAF antibody VE1 on FNA direct smears. METHODS: The authors identified 51 FNA specimens that had subsequent surgical resection specimens with a diagnosis of PTC. BRAF VE1 IHC was performed on the surgical specimens to determine their mutation status. The corresponding direct smears were then stained using the same VE1 stain to assess correlation. RESULTS: Twenty-two of the 46 included surgical specimens were positive for BRAF mutations (47.8%) by IHC, consistent with the published rates. The paired cytologic smears from these cases revealed 65.3% concordance. The overall sensitivity of BRAF staining on cytologic smears was 63.6%, and the specificity was 58.3%. Concordance rates were highest in specimens that were diagnosed as malignant or suspicious for malignancy (75% and 85.7%, respectively). The negative predictive value increased to 77.8% when suspicious for follicular neoplasm/suspicious cases were combined. CONCLUSIONS: Specimens that were malignant or suspicious on FNA were most likely to be BRAF concordant. Limitations to the interpretation of smears included low cellularity and obscuring blood, macrophages, or colloid. With further refinement, it is possible that BRAF immunocytochemistry can be applied prospectively to thyroid FNAs for risk stratification and to reduce false-negative rates.

Antiproliferative effects of Src inhibition on medullary thyroid cancer.

There is no effective treatment for recurrent or metastatic medullary thyroid cancer (MTC). Hereditary MTC is associated with mutations in the RET protooncogene, which encodes for a tyrosine kinase. We postulated that Src tyrosine kinases regulate MTC proliferation. Proliferation of the human MTC cell line, TT, was examined in the presence of a Src-specific tyrosine kinase inhibitor, PP2, or genistein. Cell counts were performed with a Coulter counter or by flow cytometry. DNA synthesis was evaluated by bromodeoxyuridine incorporation. A cell death ELISA was used to assess apoptosis. Akt phosphorylation was determined by Western immunoblot. MAPK activity was measured using an immunoprecipitation kinase assay, and MAPK inhibition was achieved with SB202190 (p38 MAPK) and PD098059 (MAPK kinase). Data were analyzed by ANOVA. Compared with controls, PP2 reduced DNA synthesis, abolished Akt phosphorylation, and increased apoptosis. The MAPK kinase inhibitor, PD098059, attenuated DNA synthesis, whereas genistein caused modest declines in cell count and DNA synthesis and minimal changes in apoptosis. We conclude that Src-dependent MTC proliferation occurs via increased DNA synthesis and reduced apoptosis. The latter effect may be mediated by Akt survival signals. Modulation of Src activity is a potential therapeutic target in MTC.

RET signals through focal adhesion kinase in medullary thyroid cancer cells.

BACKGROUND: The RET proto-oncogene is implicated in medullary thyroid cancer (MTC) and has been shown to signal indirectly to focal adhesion kinase (FAK) in cell types other than MTC. We have previously shown that FAK is phosphorylated in MTC cells. We hypothesized that inhibition of RET with pharmacologic inhibitors or by depletion with siRNA would decrease FAK phosphorylation in MTC cells, thereby implicating a RET-FAK signaling pathway. METHODS: Human MTC cells (TT cells) were treated with pharmacologic inhibitors or transfected with RET siRNA. Total protein was detected by immunoblotting. Phosphorylated FAK was detected by immunoprecipitating total FAK and immunoblotting with antiphosphotyrosine. RESULTS: Treatment of MTC cells with the inhibitor PP2 significantly inhibited RET phosphorylation and, to a lesser extent, FAK phosphorylation. Imatinib mesylate inhibited FAK phosphorylation only at high doses. RET siRNA significantly decreased RET expression and FAK phosphorylation. CONCLUSIONS: RET signals through FAK in MTC cells. Whether this is due to a direct or indirect interaction is not yet clear. PP2 or a similar inhibitor might be a useful treatment for MTC.

American Thyroid Association design and feasibility of a prospective randomized controlled trial of prophylactic central lymph node dissection for papillary thyroid carcinoma.

BACKGROUND: The role of prophylactic central lymph node dissection in papillary thyroid cancer (PTC) is controversial in patients who have no pre- or intraoperative evidence of nodal metastasis (clinically N0; cN0). The controversy relates to its unproven role in reducing recurrence rates while possibly increasing morbidity (permanent hypoparathyroidism and unintentional recurrent laryngeal nerve injury). METHODS AND RESULTS: We examined the design and feasibility of a multi-institutional prospective randomized controlled trial of prophylactic central lymph node dissection in cN0 PTC. Assuming a 7-year study with 4 years of enrollment, 5 years of average follow-up, a recurrence rate of 10% after 7 years, a 25% relative reduction in the rate of the primary endpoint (newly identified structural disease; i.e., persistent, recurrent, or distant metastatic disease) with central lymph node dissection and an annual dropout rate of 3%, a total of 5840 patients would have to be included in the study to achieve at least 80% statistical power. Similarly, given the low rates of morbidity, several thousands of patients would need to be included to identify a significant difference in rates of permanent hypoparathyroidism and unintentional recurrent laryngeal nerve injury. CONCLUSION: Given the low rates of both newly identified structural disease and morbidity after surgery for cN0 PTC, prohibitively large sample sizes would be required for sufficient statistical power to demonstrate significant differences in outcomes. Thus, a prospective randomized controlled trial of prophylactic central lymph node dissection in cN0 PTC is not readily feasible.