[Progress and controversy on the extent of surgery for medullary thyroid carcinoma based on calcitonin levels].

Medullary thyroid carcinoma (MTC) is a neuroendocrine tumor originating from the parafollicular cells (C cells) of the thyroid gland, classified as sporadic and hereditary. Calcitonin (Ctn) secreted by the C cells is a specific serological marker for MTC, which is of great value in diagnosis, treatment and postoperative management of MTC. The effect of chemoradiotherapy and 131I therapy on MTC is limited, with surgery being the primary therapy. Given the aggressive nature and relatively poor prognosis of MTC, the reasonable surgical extent is crucial for improving cure rate and prognosis of patients. However, there are still some controversies regarding the extent of surgery for MTC. This article elaborates on the research progress and controversies of serum Ctn levels in assisting the evaluation of the extent of surgery for MTC.

Serum miR-375 for Diagnostic and Prognostic Purposes in Medullary Thyroid Carcinoma.

Purpose: Having previously demonstrated that tissue miR-375 expression in medullary thyroid carcinoma (MTC) tissues is linked to prognosis, the aim of this study was to assess the diagnostic and prognostic value of circulating miR-375 levels in MTC patients. Methods: A series of 68 patients with MTC was retrospectively retrieved and assessed in terms of their clinicopathological characteristics. MiR-375 levels were measured in all patients' presurgical blood samples. Both serum and tissue levels were tested prior to surgery in a subgroup of 57 patients. Serum miR-375 levels were also measured in serum from 49 patients with non-C-cell thyroid nodular diseases (non-CTN), 14 patients with pheochromocytoma, and 19 healthy controls. Results: Circulating miR-375 levels were 101 times higher in the serum of patients with MTC than in all other patients and controls, with no overlap (P < 0.01). No correlation emerged between serum and tissue miR-375 levels. Serum miR-375 levels were higher in MTC patients with N0 than in those with N1 disease (P = 0.01), and also in patients who were biochemically cured than in those who were not (P = 0.02). In the whole series of patients and controls, calcitonin (CT) and serum miR-375 levels were correlated at diagnosis (R2 = 0.40, P < 0.01), but in a U-shaped manner: a positive correlation was found with low CT levels, then the correlation turns negative as CT rises (in MTC patients). A negative correlation was indeed found in MTC patients between serum miR-375 and CT (R2 = -0.10, P = 0.01). On ROC curve analysis, a cut-off of 2.1 for serum miR-375 proved capable of distinguishing between MTC patients and the other patients and controls with a 92.6% sensitivity and a 97.6% specificity (AUC: 0.978, P < 0.01). Conclusions: Serum miR-375 levels can serve as a marker in the diagnosis of MTC, with a remarkable specificity. Serum miR-375 also proved a novel marker of prognosis in this disease. Further in vitro experiments to corroborate our results are currently underway.

Hereditary medullary thyroid carcinoma syndromes: experience from western India.

The data from the Indian subcontinent on Medullary thyroid carcinoma (MTC) and associated endocrinopathies in hereditary MTC (HMTC) syndromes are limited. Hence, we analyzed clinical and biochemical characteristics, management, and outcomes of HMTC and other associated endocrinopathies [Pheochromocytoma (PCC) and Primary hyperparathyroidism (PHPT)] and compared with apparently sporadic MTC. The records of 97 (51 sporadic and 46 hereditary) consecutive MTC patients were retrospectively analyzed. RET mutation was available in 38 HMTC patients. HMTC group was subclassified into Multiple endocrine neoplasia (MEN) 2A index (n = 25), MEN2B index (n = 8), and MEN2A detected by familial screening (n = 12). Patients with HMTC and MEN2B index were younger at presentation than sporadic MTC. MEN2A patients detected by familial screening, but not MEN2A index and MEN2B index patients, had significantly lower serum calcitonin, smaller thyroid nodule size, more frequent early stage presentation (AJCC Stage ≤ II), and higher cure rate than sporadic MTC, which emphasizes the need for early diagnosis. RET (REarranged during Transfection) 634 mutations were the most common cause of HMTC and more frequently associated with PCC (overall 54% and 100% in those aged ≥ 35 years). Patients in ATA-Highest (HST) group had a universal presentation in stage IV with no cure. In contrast, the cure rate and postoperative disease progression (calcitonin doubling time) were similar between ATA-High (H) and ATA- Moderate (MOD) groups, suggesting the need for similar follow-up strategies for the latter two groups. Increased awareness of endocrine (PCC/PHPT) and non endocrine components may facilitate early diagnosis and management.

Basal and pentagastrin-stimulated calcitonin cut-off values in diagnosis of preoperative medullary thyroid cancer

Background/aim: Medullary thyroid cancer (MTC) originates from parafollicular cells (C cell) and produces calcitonin (CT). Basal serum CT was used in the diagnosis and treatment of MTC. If basal CT level is 100 pg/mL or higher, it is likely to have MTC, but if basal CT level is below 10 pg/mL, the probability of developing thyroid disease is low. In cases with basal CT level between 10­100 pg/mL, pentagastrin-stimulated (PS) CT level is studied to evaluate MTC and C cell hyperplasia (CHH). This study aimed to determine cut-off value for basal and PS peak CT level for diagnosis of MTC. Materials and methods: We retrospectively reviewed files of patients presented to endocrine outpatient clinic of Ege University, Medicine School, between 2010 and 2019; 176 patients with basal CT level of 10­100 pg/mL and patients with PS test were included to the study. Results: The receiver operating characteristic curve (ROC) analysis was used to determine cut-off value for basal CT that can discriminate cases with MTC and those with nodular goiter. Cut-off value for basal CT was calculated as 46.5 pg/mL (specificity; 100 %, sensitivity; 74 %). In the ROC analysis for peak PS CT, cut-off value was calculated as 285 pg/mL (specificity:100 %; sensitivity:82 %). When peak CT level was > 290 pg/mL in PS test, both specificity and sensitivity for MTC were determined as 100 %. The PS peak CT level > 285 pg/ mL was significant for MTC diagnosis while range of 117­274 pg/mL was significant for CHH. Conclusion: In this study, cut-off value was calculated as 46.5 pg/mL for basal CT, whereas 285 pg/mL for PS peak CT in the diagnosis of preoperative MTC.

Calcitonin testing for detection of medullary thyroid cancer in people with thyroid nodules.

BACKGROUND: Thyroid nodules are very common in general medical practice, but rarely turn out to be a medullary thyroid carcinoma (MTC). Calcitonin is a sensitive tumour marker for the detection of MTC (basal calcitonin). Sometimes a stimulation test is used to improve specificity (stimulated calcitonin). Although the European Thyroid Association's guideline advocates calcitonin determination in people with thyroid nodules, the role of routine calcitonin testing in individuals with thyroid nodules is still questionable. OBJECTIVES: The objective of this review was to determine the diagnostic accuracy of basal and/or stimulated calcitonin as a triage or add-on test for detection of MTC in people with thyroid nodules. SEARCH METHODS: We searched CENTRAL, MEDLINE, Embase and Web of Science from inception to June 2018. SELECTION CRITERIA: We included all retrospective and prospective cohort studies in which all participants with thyroid nodules had undergone determination of basal calcitonin levels (and stimulated calcitonin, if performed). DATA COLLECTION AND ANALYSIS: Two review authors independently scanned all retrieved records. We extracted data using a standard data extraction form. We assessed risk of bias and applicability using the QUADAS-2 tool. Using the hierarchical summary receiver operating characteristic (HSROC) model, we estimated summary curves across different thresholds and also obtained summary estimates of sensitivity and specificity at a common threshold when possible. MAIN RESULTS: In 16 studies, we identified 72,368 participants with nodular thyroid disease in whom routinely calcitonin testing was performed. All included studies performed the calcitonin test as a triage test. Median prevalence of MTC was 0.32%. Sensitivity in these studies ranged between 83% and 100% and specificity ranged between 94% and 100%. An important limitation in 15 of the 16 studies (94%) was the absence of adequate reference standards and follow-up in calcitonin-negative participants. This resulted in a high risk of bias with regard to flow and timing in the methodological quality assessment. At the median specificity of 96.6% from the included studies, the estimated sensitivity (95% confidence interval (CI)) from the summary curve was 99.7% ( 68.8% to 100%). For the median prevalence of MTC of 0.23%, the positive predictive value (PPV) for basal calcitonin testing at a threshold of 10 pg/mL was 7.7% (4.9% to 12.1%). Summary estimates of sensitivity and specificity for the threshold of 10 pg/mL of basal calcitonin testing was 100% (95% CI 99.7 to 100) and 97.2% (95% CI 95.9 to 98.6), respectively. For combined basal and stimulated calcitonin testing, sensitivity ranged between 82% and 100% with specificity between 99% and 100%. The median specificity was 99.8% with an estimated sensitivity of 98.8% (95% CI 65.8 to 100) . AUTHORS' CONCLUSIONS: Both basal and combined basal and stimulated calcitonin testing have a high sensitivity and specificity. However, this may be an overestimation due to high risk of bias in the use and choice of reference standard The value of routine testing in patients with thyroid nodules remains questionable, due to the low prevalence, which results in a low PPV of basal calcitonin testing. Whether routine calcitonin testing improves prognosis in MTC patients remains unclear.

Early Diagnosis of Medullary Thyroid Cancer: Are Calcitonin Stimulation Tests Still Indicated in the Era of Highly Sensitive Calcitonin Immunoassays?

Background: Measurements of both basal (b) calcitonin (CT) and calcium (Ca)-stimulated CT (Ca-sCT) levels are performed to identify medullary thyroid cancer (MTC) at an early stage when used as part of the diagnostic workup of thyroid nodules (CT screening). Novel immunochemiluminometric assays, which are highly sensitive and specific for monomeric CT and avoid cross-reactivity, have been introduced over the past decade. No prospectively generated data have so far become available to answer the frequently raised question as to whether Ca-sCT in contrast to bCT alone is helpful and, therefore, still indicated for the early detection of MTC. Methods: Ca-stimulation tests were performed in 149 consecutive patients with thyroid nodules and elevated bCT. Regardless of Ca-sCT levels, all patients had an operation applying a uniform surgical protocol, including thyroidectomy and systematic lymph node dissection. Recently published sex-specific cutoff levels for the differentiation of MTC and other C-cell pathologies (C-cell hyperplasia [CCH]) were used to compare the diagnostic performance of bCT or Ca-sCT alone and in combination using receiver-operating characteristic (ROC) analysis. In addition, CT cutoff levels to predict lateral lymph node metastasis were evaluated for bCT compared with Ca-sCT. Follow-up for all patients was documented and correlated with initial CT levels. Results: MTC was identified in 76 (50.1%) patients, in 21/76 (27.6%) with lymph node and in 4 (5.3%) with distant metastasis. Using predefined cutoff levels, patients could effectively be subdivided into a group above the cutoff level with definitive diagnosis of MTC (100%) and below (gray zone) with a significant overlap of CCH and MTC (all classified as pT1a; males: 19/58 [37.5%], females: 7/41 [17.1%]). The areas under the ROC curve (AUC) were excellent for the diagnosis of MTC in all tests. Determination of bCT proved to be superior for both diagnosing MTC in males (AUC for bCT: 0.894; AUC for Ca-sCT: 0.849) and females (bCT: 0.935; Ca-sCT: 0.868) and also for diagnosing lymph node metastasis in the lateral compartment (males: bCT: 0.925; Ca-sCT: 0.810; females: bCT: 0.797; Ca-sCT: 0.674). Combining both tests did not improve diagnostic accuracy. Using a cutoff level of >85 pg/mL for females and >100 pg/mL for males, the sensitivity for diagnosing lateral neck lymph node metastasis was 100%. Below these cutoff levels, no patient showed persistent or recurrent disease (median follow-up: 46 [ ± 27] months). Conclusions: Predefined sex-specific bCT cutoff levels are helpful for the early detection of MTC and for predicting lateral neck lymph node metastasis. Ca-sCT did not improve preoperative diagnostics. bCT levels >43 and >100 pg/mL for males and of >23 and >85 pg/mL for females are relevant for advising patients and planning the extent of surgery.

Expressions of IL-17 and TNF-α in patients with Hashimoto's disease combined with thyroid cancer before and after surgery and their relationship with prognosis.

OBJECTIVE: This study aimed to investigate expressions and clinical significance of IL-17 and TNF-α after surgery in patients with Hashimoto's disease (HD) combined with thyroid cancer (TC). PATIENTS AND METHODS: From June 2010 to October 2012, 38 patients with HD combined with TC admitted to the oncology department of Tongji Hospital were selected as an experimental group, including three males and 35 females, aged 24-78 years. Forty adults undergoing physical examination during the same period were selected as a control group. All patients in the experimental group were given total endoscopic TC resection. Real-time fluorescence quantification (qRT-PCR) and enzyme-linked immunosorbent assay (ELISA) were used to detect the expression levels of serum IL-17 and TNF-α before and 14 days after surgery. Patients with HD combined with TC were divided into high and low expression groups according to the median values of preoperative IL-17 mRNA and TNF-α mRNA. The relationship between IL-17, TNF-α, and prognosis of patients was analyzed through K-M survival curve. RESULTS: The concentrations of IL-17 and TNF-α in serum were also higher than those in control group 14 days after surgery (p < 0.05). qRT-PCT showed that the relative expressions of IL-17 and TNF-α in serum 14 days after surgery were higher than those in control group (p < 0.05). According to the relative expression median of mRNA in IL-17 and TNF-α before surgery, they were divided into high and low expression groups. It was found that the survival rate of high expression groups of IL-17 and TNF-α was lower than that of low expression groups (IL-17, p = 0.028; TNF-α, p = 0.014). CONCLUSIONS: The protein and mRNA of IL-17 and TNF-α in serum of HD patients with TC are higher than those of healthy control group. Expressions of IL-17 and TNF-α can be reduced by surgical resection of focal tissue. IL-17 and TNF-α may be used as potential prognostic indicators of HD patients with TC.

Sentinel lymph node biopsy in medullary thyroid microcarcinomas.

The aim of this prospective study was to analyze accuracy of sentinel lymph node biopsy with methylene blue dye for intraoperative detection of lateral metastases in clinically N0M0 medullary microcarcinomas with calcitonin <1,000 pg/mL and selection of true-positive patients for one-time therapeutic lateral dissection. In addition to total thyroidectomy and central neck dissection, all patients had bilateral sentinel biopsy of jugulo-carotid regions after methylene blue injection to decide upon necessity for lateral dissection. If sentinels were benign on frozen section, additional non-sentinels were extirpated, with no further lateral dissection. If sentinels were malignant, one-time lateral dissection was performed. 20 patients were included in this study. Hereditary disease form was observed in 3/20 (15%) of patients with RET proto-oncogene mutation C634F; remaining 17/20 (85%) were negative for germline mutations. There were no allergic reactions to methylene blue and identification rate of sentinels was 100%. In total, 2/20 (10%) cN0 patients had lymphonodal metastases, thus were reclassified as pN1b. Remaining 18/20 (90%) were classified pN0 based on standard pathohistology. Frozen section findings on sentinels were 100% match with standard pathohistology, and there were no skip metastases in lateral compartments. Sensitivity, specificity and accuracy of sentinel biopsy method with methylene dye and frozen section were 100%. Dzodic's sentinel lymph node biopsy method can be used for intraoperative assessment of lateral compartments and optimization of initial surgery of medullary microcarcinomas with calcitonin <1,000 pg/mL. This way, cN0 patients with sentinel metastases can receive one-time lateral dissection, and those without benefit from less extensive surgery.

Current surgical management in RET mutation carriers [Aktualne postepowanie chirurgiczne u nosicieli mutacji proto-onkogenu RET].

Medullary thyroid carcinoma (MTC) still remains a rare endocrine tumor. 20-25% of MTC cases are genetically determined. The detection of the RET proto-oncogene mutation in 1993 allowed to understand the unique genotype-phenotype relationships in hereditary medullary thyroid carcinoma (HMTC) and formed the basis for therapeutic decisions based on the molecular results. Currently, prophylactic thyroidectomy is a commonly adopted and accepted therapeutic method. The decision on the time and extent of surgery should be made based on the results of molecular examination, the assessment of calcitonin (Ct) concentration and family history. Treatment of patients with HMTC requires the cooperation of a multidisciplinary team of experts and should be done in specialized centers only. The study is a review of the current guidelines for surgical management in the MEN2 syndrome.

Genetic analysis of a hereditary medullary thyroid carcinoma case with normal preoperative serum calcitonin levels.

CONTEXT: Serum calcitonin is often elevated in medulla thyroid carcinoma (MTC) and thus serves as an indicator of primary and recurrent disease. However, there are MTC patients with normal Serum calcitonin and the underlying mechanisms are largely unknown. CASE DESCRIPTION: A 48-year-old female patient presenting with a right anterior cervical mass was diagnosed with medullary carcinoma. She had elevated carcinoembryonic antigen (CEA) but normal Serum calcitonin levels. Next generation sequencing (NGS) of paired tumor and peripheral blood revealed a germline pathogenic RET mutation, indicating the hereditary nature of MTC in this patient. Two somatic loss-of-function mutations in DICER1 gene were also found, which we postulated to account for the normal calcitonin levels found in this patient. To our knowledge, this is the first report of a hereditary MTC case displaying a normal Serum calcitonin. CONCLUSIONS: The case suggests NGS can be used in the diagnosis of hereditary MTC and exploring the reasons of normal Serum calcitonin in these patients.

[Clinical significance and cost-benefit analysis of serum calcitonin assay in diagnosis and treatment of medullary thyroid carcinoma].

Objective: To study the clinical significance of serum calcitonin in the diagnosis and treatment of medullary thyroid carcinoma and to analyze its cost-benefit. Methods: One hundred and forty one patients with medullary thyroid carcinoma who undertook calcitonin test and frozen pathological examination were enrolled in this study from Oct 2012 to Mar 2018. Using the method of χ(2) test, the positive rate of calcitonin test and frozen pathological examination in diagnosis of medullary thyroid carcinoma(MTC) were compared. Firstly, we compared the correct checkout cost of calcitonin test and that of frozen pathological examination (total number of patients×cost of examination/the correctly detected number of patients) . Secondly, we calculated whether calcitonin test help patients save money(average cost of treatment in hospital for MTC×number of patients who were evaluated to be candidate for surgery-cost of calcitonin test×total number of patients)/total number of patients. Results: 139 patients were positive in calcitonin test among 141 patients, and the positive rate was 98.58%. 91 patients were positive in frozen pathological examination, and the positive rate was 64.54% (χ(2)=97.821, P<0.000 1) . Cost-benefit analysis showed that the correct checkout cost of calcitonin test and frozen pathological examination were 71.01 yuan and 426.10 yuan, also,1 371 938.64 yuan could be saved totally and 9 730.06 yuan could be saved per patient because of calcitonin test. Conclusion: Serum calcitonin test had a significant effect on the diagnosis and treatment of medullary thyroid carcinoma and was economical and practical.

Dysregulation in IGF-1R, FGFR4 and ßKlotho signaling in patients with medullary thyroid cancer.

BACKGROUND: Medullary thyroid cancer (MTC) is a relatively rare thyroid neoplasm derived from neuroendocrine C cells which secrete calcitonin. αKlotho (αKL) and ßKlotho (ßKL) are transmembrane proteins which modulate different signaling systems, such as endocrine FGFs and IGF1 pathways. Dysregulation of the FGF19/FGFR4/ßKL and IGF-1/IGF-1R/αKL signaling axes has been implicated in the pathogenesis of several cancers. However, their role in the pathogenesis of MTC has not been determined. METHODS: The aim of this study was to assess αKL, ßKL, FGF19, IGF-1, FGFR4, and IGF-1R concentrations in a group of 11 patients with medullary thyroid cancer (MTC). The control group consisted of 20 healthy volunteers. Serum concentrations of these factors were measured using specific ELISA methods. RESULTS: Significantly lower concentrations of ßKL and higher concentrations of FGFR4 and IGF-1R were found in patients with MTC as compared to controls. CONCLUSIONS: Our results indicate that a disrupted signaling pathway for ßKL, FGFR4 and IGF-1R may play a role in the development of medullary thyroid cancers. However, further studies are required to confirm these findings and to use this knowledge in clinical practice.

Long-term outcome after DNA-based prophylactic neck surgery in children at risk of hereditary medullary thyroid cancer.

Advances in sequencing technology, providing unprecedented insights into cancer progression, have shifted the treatment paradigm towards precision medicine for hereditary medullary thyroid cancer (MTC), away from the 'one-size-fits-all' approach predicated on genetic risk alone. The DNA-based/biochemical concept, factoring serum calcitonin into the benefit-risk equation, optimizes biochemical cure while minimizing extent of prophylactic surgery and operative morbidity in children at risk. The transformative effect that has taking effect on medical practice has been impressive: Increasingly earlier molecular diagnosis and more limited prophylactic neck operations yielded excellent clinical outcomes at expert facilities 7-16 years postoperatively: biochemical cure rates approximating 100%; absence of residual structural disease or recurrence; and rarely any permanent operative morbidity. These excellent results, contingent on proper health care funding and pediatric surgical specialization, make a case for early prophylactic thyroidectomy in experienced hands once calcitonin serum levels exceed the upper normal limit of the assay in young gene carriers.

68Ga-DOTANOC and 18F-FDG PET/CT in metastatic medullary thyroid carcinoma: novel correlations with tumoral biomarkers.

OBJECTIVE: Metastatic disease is common in medullary thyroid carcinoma (MTC) and it is usually detected by raising calcitonin and carcinoembryonic antigen (CEA) levels. Nuclear medicine imaging has an important role in lesion identification/characterisation. We aim to compare 68Ga-DOTANOC PET/CT and 18F-FDG PET/CT performance and to explore the correlations between tumoral markers and functional imaging. METHODS: This a retrospective cross-sectional study including 13 patients with MTC and high calcitonin/CEA levels that underwent both 68Ga-DOTANOC PET/CT and 18F-FDG PET/CT. RESULTS: 68Ga-DOTANOC PET/CT identified MTC metastases in 2twopatients that were 18F-FDG-negative (sensitivity of 69.2% vs. 53.9%, respectively). 68Ga-DOTANOC PET/CT also detected a higher number of lesions than 18F-FDG PET/CT in seven patients, with only one patient showing the opposite pattern. Both differences lacked statistical significance (p = 0.50 and p = 0.86, respectively) but 68Ga-DOTANOC PET/CT better performance allowed changes in patients' management. 68Ga-positive/18F-FDG-negative patients were the ones with the lowest calcitonin doubling time and presented a CEA doubling time >24 months, while the patient with more 18F-FDG-positive lesions was the one with the highest CEA/calcitonin ratio. The number of lesions found in 68Ga-DOTANOC PET/CT were correlated with calcitonin levels (r = 0.73; p < 0.01) but not with CEA ones (r = 0.42; p = 0.15). The number of 18F-FDG hypermetabolic focus were correlated with CEA levels (r = 0.60; p < 0.05) but not with calcitonin (r = 0.48; p = 0.09). CONCLUSIONS: This is the first study to describe a positive correlation between 68Ga-positive lesions and calcitonin levels and between 18F-FDG-positivity and CEA levels. Tumoral markers pattern in metastatic MTC could help clinicians to decide which exam to perform first.

Anlotinib for the Treatment of Patients with Locally Advanced or Metastatic Medullary Thyroid Cancer.

BACKGROUND: The prognosis of advanced or metastatic medullary thyroid carcinoma (MTC) is poor, and there are few therapeutic options. Anlotinib has previously shown promising antitumor activity on MTC in preclinical models and a Phase I study. This Phase II clinical trial was devised to confirm the antitumor activity of anlotinib in patients with advanced or metastatic MTC. METHODS: Patients with unresectable locally advanced or metastatic MTC received once daily oral anlotinib 12 mg, two weeks on/one week off, until disease progression, death, unacceptable toxicity, or withdrawal of consent for any reason. The dose was adjusted on the basis of observed toxicity. The primary endpoint was progression-free survival (PFS). RESULTS: Fifty-eight patients received anlotinib treatment. The primary endpoint PFS has not yet been reached at the time of analysis. On the basis of investigator assessments, 56.9% of patients experienced a partial response. PFS rate at 48 weeks was 85.5%. Forty-five patients had a ≥50% decrease in serum calcitonin concentration from baseline. The most common adverse events were hand-foot syndrome, hypertriglyceridemia, cholesterol elevation, fatigue, and proteinuria. CONCLUSIONS: Anlotinib demonstrated a durable antitumor activity with a manageable adverse event profile in locally advanced or metastatic MTC.

[Recommendation for Calcitonin Screening in Nodular Goiter]. / Empfehlung zum Calcitonin-Screening bei Struma nodosa.

Medullary thyroid cancer (MTC) arises from parafollicular C cells of the thyroid gland and is characterized by a calcitonin secretion. Basal calcitonin correlates with the tumor mass and is used as highly sensitive and specific tumor marker for MTC. Based on former assays, unspecific calcitonin increase has frequently been seen in Hashimoto's thyroiditis, kidney insufficiency, proton pump inhibitors etc. This phenomenon is now less often seen with modern assays. The consequent use of calcitonin measurement in nodular goiter helps to identify the rare MTC at an early stage. The best cut-off values to differentiate micro-MTC from C-cell hyperplasia and other unspecific calcitonin elevations were achieved by the use of a 30 pg/ml and a 60 pg/ml threshold in women and men, respectively. This approach is not less sensitive than formerly used pentagastrin stimulation. A calcitonin value > 100 pg/ml is nearly 100 % predictive for MTC. Therefore, the Thyroid Section of the German Society of Endocrinology recommends a thyroidectomy in woman with serum calcitonin values > 30 pg/ml (grey zone 20 - 30 pg/ml) and in man with serum calcitonin values > 60 pg/ml (grey zone 30 -60 pg/ml). Lower calcitonin values should be re-evaluated in intervals of 3 - 6 months; rising calcitonin levels may indicate an MTC. In this case, thyroid operation should be performed. The cure rate of MTC with calcitonin values < 100 pg/ml is nearly 100 % done by high volume surgeons.

Radioguided hepatic resection with 18F-DOPA in a patient with metastatic medullary thyroid carcinoma. / Resección hepática radioguiada con 18F-DOPA en un paciente con carcinoma medular de tiroides metastásico.

INTRODUCTION: Medullary carcinoma accounts for 1-2% of all thyroid malignancies. 13-20% of patients present with distant metastasis, with 45% of the cases affecting the liver. CLINICAL CASE: A 50-year-old woman, diagnosed with medullary thyroid carcinoma, was treated with total thyroidectomy and a modified neck dissection in 1999. Two lymph node recurrences in the neck were treated with surgical resection; during surveillance, she developed elevated calcitonin levels, the recurrence site was identified with 18F-DOPA PET/CT in the liver. Metabolic activity was not associated with a visible lesion in CT, MRI nor ultrasound. Radioguided surgery with 18F-DOPA allowed an anatomic resection of segments IVb and V. DISCUSSION: In patients with medullary carcinoma and elevated calcitonin during surveillance, 18F-DOPA PET/CT is an option to evaluate the site of recurrence. Radioguided resection was feasible in this patient, whose hepatic recurrence was not visible with any other imaging method. CONCLUSION: Radioguided hepatic resection with 18F-DOPA in metastatic medullary thyroid carcinoma is feasible when the recurrence site is not anatomically identified by any other imaging studies.

Preoperative Clinical and Sonographic Predictors for Lateral Cervical Lymph Node Metastases in Sporadic Medullary Thyroid Carcinoma.

BACKGROUND: Total thyroidectomy and cervical lymph node (LN) dissection is generally recommended in patients with medullary thyroid carcinoma (MTC). However, there is no clear evidence for whom to perform prophylactic lateral neck dissection in MTC patients without evident lateral cervical lymph node (LCLN) metastasis in preoperative images. This study evaluated the preoperative features for predicting the LCLN metastasis of MTC. METHODS: The study included 26 MTC patients with LCLN metastasis at initial surgery (N1b group) and 47 MTC patients without any LN metastasis or recurrence of disease (N0-NED group). The association between LCLN metastasis and preoperative clinical and sonographic characteristics (size, location, solid component, shape, margin, echogenicity, calcification, and subcapsular location of the tumor) were evaluated. RESULTS: There were no significant differences in age and sex between the N1b and N0-NED groups. Preoperative serum levels of calcitonin >65 pg/mL were associated with LCLN metastasis (p < 0.001). In preoperative neck ultrasonography (US), patients in the N1b group were more commonly found with a larger tumor (>1.5 cm) of irregular shape with a spiculated margin and a subcapsular location than those in the N0-NED group (p = 0.029, p < 0.001, p < 0.001, and p < 0.001, respectively). Increases in the number of these LCLN metastasis-related features were significantly associated with higher risk for LCLN metastasis (p < 0.001). The presence of two or more predictors was an appropriate cutoff point for predicting LCLN metastasis of MTC with 73.1% sensitivity and 91.5% specificity. CONCLUSIONS: MTC tumors with high preoperative calcitonin levels (>65 pg/mL), larger size (>1.5 cm), irregular shape, spiculated margins, and subcapsular locations in the neck US are at higher risk for LCLN metastasis. MTC patents with fewer than two predictors might be suitable for treatment without prophylactic LCLN dissection.

Intraoperative calcitonin stimulation testing in the surgical treatment of C-cell disease.

OBJECTIVE: The prognosis of medullary thyroid carcinoma (MTC), derived from parafollicular C-cells, depends on the completeness of the initial surgical excision. The C-cells produce calcitonin, a peptide hormone used as a biochemical and immunohistochemical tumor marker. The aim of the study was to evaluate an individualized approach to patients with C-cell disease, i.e. MTC and C-cell hyperplasia (CCH), using the intraoperative calcitonin testing-assisted surgical strategy as a predictor of the final outcome. STUDY DESIGN: A unicentre cross-sectional study. METHODS: From June 2009 to May 2015, thirty one patients with MTC/CCH were surgically treated primarily (n=24) or reoperated for persistence of the disease (n=7). Depending on the result of intraoperative calcitonin stimulation testing (iCST), patients underwent total thyroidectomy with or without lymph node dissection. All patients were tested repeatedly in the postoperative period (range 1 to 48 months). RESULTS: The iCST was true negative in all CCH, and ten out of eleven N0 MTC primarily operated patients, and true positive in one N0 patient and six of the seven reoperated patients. The test was false negative in two patients preoperatively evaluated as N+, one primarily operated and one reoperated, respectively. CONCLUSION: The results encourage the use of an individualised approach on patients with MTC/CCH, e.g. to be less radical surgically in cases of negative iCST, and to be more radical in those patients with persistent increase of serum calcitonin. The absence of post-stimulation calcitonin elevation in iCST seems to be a good prognosis indicator in patients with an early-stage C-cell disease, but longer follow-up is needed.