Spontaneous and Treatment-Related Changes of Serum Calcitonin in Medullary Thyroid Cancer: Long-Term Experience in a Patient With Multiple Endocrine Neoplasia Type 2B

PURPOSE

Medullary thyroid carcinoma (MTC) in MEN2B syndrome is associated with germline RET mutation. Patients harboring de novo mutations are usually diagnosed at more advanced disease stages. We present a young woman with Met918Th mutation diagnosed with stage IV MTC at age 10 years.

METHODS

The disease progressed despite total thyroidectomy and multiple surgical interventions for cervical lymph node recurrences, leading to distant metastases in the fifth year after the initial diagnosis. Subsequently, she underwent five different types of tyrosine kinase inhibitor (TKI) treatments. The 17-year disease course was divided into periods defined by four surgical interventions and sequential treatment intervals with four multikinase (sunitinib, vandetanib, cabozantinib, and lenvatinib) and one RET-selective TKI (selpercatinib). Tumor growth for different phases of spontaneous development and drug treatment intervals was characterized by changes in serial log-transformed calcitonin measurements (n = 114).

RESULTS

Three operations (one for calcitonin-producing adrenal pheochromocytoma) were associated with drops in calcitonin levels. All of the nonselective TKIs were stopped due to adverse effects. As reflected by the negative calcitonin doubling rate, the best treatment response was observed with selpercatinib, which was associated with an initial large drop followed by a decreasing calcitonin trajectory over 514 days without any major side effects.

CONCLUSION

This case of MEN2B medullary thyroid cancer with long-term survival presents how the effectiveness of different treatment modalities can be estimated using log-transformed calcitonin levels. Furthermore, our experience supports the view that serial calcitonin measurements may be more sensitive than radiological follow-up in advanced MTC. Our patient also represents a new case of rarely reported calcitonin-producing pheochromocytomas.

Preoperative calcitonin testing improves the diagnosis of medullary thyroid carcinoma in female and male patients

AIM

Calcitonin (Ctn) measurement in patients with thyroid disease could potentially increase the detection rates of medullary thyroid carcinoma (MTC) but remains a controversial issue. The aim of this study was to evaluate routine preoperative Ctn measurements.

METHODS

All patients with thyroid surgery documented in the prospective StuDoQ|Thyroid registry between March 2017 and September 2020 were included. Cutoff levels for Ctn were determined with receiver-operating characteristic analyses to assess the preoperative diagnosis of MTC in subgroups for females and males.

FINDINGS

In 29 590 of 39 679 patients (75%) participating in the registry, routine preoperative Ctn testing was performed. In 357 patients (227 females and 130 males), histopathology confirmed MTC with a mean tumor size of 14.7 mm (±12.43). Biochemical cure was achieved in 71.4% of the patients. Ctn levels between 11 and 20 pg/mL were seen in 2.6% of the patients, and only 0.7% of the patients had Ctn levels above 21 pg/mL. Cutoff levels for the diagnosis of MTC were 7.9 pg/mL for females and 15 pg/mL for males (P < 0.001). The sensitivity and specificity for females were 95 and 98%, and 96 and 97% for males, respectively.

CONCLUSION

Routine Ctn testing is a reliable predictor for MTC and provides the opportunity for earlier thyroidectomy before lymph node metastases occur, resulting in a better prognosis. Females with Ctn levels >7.9 pg/mL and males >15 pg/mL without any other extrathyroidal sources for an elevated Ctn should be monitored. Thyroid surgery should be considered if Ctn levels are increasing or ultrasound detects suspicious thyroid lesions.

Thresholds of Basal- and Calcium-Stimulated Calcitonin for Diagnosis of Thyroid Malignancy

Since medullary thyroid carcinoma is an aggressive cancer, it is important to have an early detection based on stimulated calcitonin (CT), especially when basal-CT is slightly elevated. The objective of this work was to set specific thresholds for basal-CT- and calcium-stimulated calcitonin for prediction of thyroid malignancy in female population. The study included 2 groups: group A-women with elevated basal-CT (>9.82 pg/ml) and group B-women with normal basal-CT (control group). After calcium stimulation test precise protocol, histopathological reports of those that required surgery were correlated with both basal and stimulated calcitonin. The best basal and stimulated calcitonin cut-offs for distinguishing female patients with medullary thyroid carcinoma or C-Cell-hyperplasia from other pathologies or normal cases were: 12.9 pg/ml, respectively 285.25 pg/ml. For basal-CT above 30 pg/ml, malignancy was diagnosed in 9/9 patients (100%): 9 MTC. For stimulated calcitonin above 300 pg/ml, malignancy was diagnosed in 17/21 patients (80.95%): 12 MTC and 5 papillary thyroid carcinomas. The smallest nodule that proved to be medullary thyroid carcinoma had only 0.56/0.34/0.44 cm on ultrasound, with no other sonographic suspicious criteria. In conclusion, we have identified in Romanian female population basal and stimulated calcitonin thresholds to discriminate medullary thyroid carcinoma or C-Cell-hyperplasia from other cases. We recommend thyroid surgery in all women with stimulated calcitonin above 285 pg/ml. Further studies on larger groups are necessary to establish and confirm male and female cut-offs for early diagnosis of medullary thyroid carcinoma, and interestingly, maybe for macro-papillary thyroid carcinomas alike. The calcium administration has minimum side-effects, but continuous cardiac monitoring is required.

Basal and stimulated calcitonin for the diagnosis of medullary thyroid cancer: updated thresholds and safety assessment

PURPOSE

Reliable cut-offs for basal (bCT) and calcium stimulated calcitonin (casCT) are needed for an early and accurate diagnosis of medullary thyroid cancer (MTC).

PATIENTS AND METHODS

Fifty-four new patients with nodular goiter were enrolled and analysed together with those previously published by our group for a total of 135 cases. bCT and casCT were measured by a highly sensitive method and the results compared with histological findings. In a subgroup of patients, cardiac rhythm was recorded before and during the calcium test.

RESULTS

In both females (F) and males (M), there was a significant correlation between tumor size and bCT levels (P < 0.001). The receiver operating characteristic plot analyses showed that, for bCT, the new cut-off points able to separate non-MTC from MTC patients were > 30 (F) and > 34 pg/mL (M), whereas the best casCT thresholds were > 79 (F) and > 466 pg/mL (M). bCT was shown to harbour a high accuracy, though some cases were diagnosed only upon stimulation test. Importantly, combining bCT, below or above the cut-offs, with casCT above the cut-offs, all the MTC cases were correctly identified. A reversible sinus bradycardia was observed in 9% of cases during the test.

CONCLUSIONS

Refined cut-offs for bCT and casCT in patients with nodular goiter are reported. Sensitive bCT was shown to have a high accuracy, but the combination with casCT data was needed to identify all MTC cases. The reliability and safety of calcium test strongly favour the routine use of CT determination in nodular thyroid disease.

Prognostic Value of Preoperative Serum Calcitonin Levels for Predicting the Recurrence of Medullary Thyroid Carcinoma

BACKGROUND

Serum calcitonin level is a useful biomarker for predicting primary tumor size, the extent of lymph node, and distant metastasis in patients with medullary thyroid carcinoma (MTC). However, the association between preoperative serum calcitonin levels and long-term oncologic outcomes has not yet been established. The aims of this study were to determine the preoperative serum calcitonin cut-off value for predicting disease recurrence and to evaluate its prognostic value.

METHODS

Patients with MTC (n = 169) who were treated at a tertiary referral hospital in Korea between 1995 and 2019 were enrolled. To determine the preoperative serum calcitonin cut-off value for predicting structural recurrence, the maximum of the standardized log-rank statistics of all possible cut-off values was used. Multivariable Cox regression analysis was used to determine prognostic factors for disease-free survival.

RESULTS

The overall disease-free survival rate was 75.7%. The preoperative serum calcitonin cut-off value that predicted structural recurrence was 309 pg/mL. Preoperative serum calcitonin levels of > 309 pg/mL were the strongest independent predictor of disease recurrence (hazard ratio (HR) 5.33, 95% confidence interval (85% CI) 1.67-16.96; P = 0.005). Lateral lymph node metastasis (HR 3.70, 95% CI 1.61-8.51; P = 0.002) and positive resection margins (HR 3.57, 95% CI 1.44-8.88; P = 0.006) were also significant predictors of disease recurrence.

CONCLUSIONS

The preoperative serum calcitonin cut-off value is useful in clinical practice. It is also the best predictive factor for disease-free survival. Preoperative serum calcitonin levels may help determine the optimal postoperative follow-up strategy for patients with MTC.

Case Report: Medullary Thyroid Cancer Workup Initiated by Unexpectedly High Procalcitonin Level-Endocrine Training Saves Life in the COVID-19 Unit

BACKGROUND

Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) is a novel coronavirus that has caused a worldwide pandemic. The majority of medullary thyroid cancers present as a thyroid nodule. At the time of diagnosis, cervical lymph nodes and distant metastases are frequently detected.

CASE REPORT

Here, we present a case of a 46-year-old man with coronavirus disease (COVID) pneumonia, who had persistently high serum procalcitonin levels despite normal C-reactive protein levels. The attending infectologist happened to be a colleague who spent some time, as part of her internal medicine rotation, in the Endocrine Ward and recalled that medullary thyroid cancer might be the cause. This led to the timely workup and treatment of the medullary cancer.

Albumin-to-Alkaline Phosphatase Ratio: Does It Predict Survival in Grade 1 and Grade 2 Neuroendocrine Tumors?

OBJECTIVES

Neuroendocrine tumors (NETs) are very heterogeneous tumors. This study aimed to evaluate prognostic value of an albumin-to-alkaline phosphatase (ALP) ratio (AAPR) in well-differentiated NETs.

METHODS

A total of 110 patients were included in this study. Albumin-to-alkaline phosphatase ratio was calculated by dividing albumin concentration (g/dL) to ALP level (U/L). Cutoff value for AAPR was determined by receiver operating characteristic analysis. Survival analysis was performed by Kaplan-Meier method with the log-rank test. A P value of less than 0.05 was considered statistically significant.

RESULTS

The optimum cutoff value for AAPR was 0.028. Patients were divided into 2 groups as patients with AAPR of 0.028 or less (n = 22, 20%) and with AAPR of greater than 0.028 (n = 88, 80%). Patients with AAPR of greater than 0.028 had statistically longer overall survival compared with patients with 0.028 or less (not reached vs 96.8 months, P = 0.001). In addition, AAPR has been shown to be an independent prognostic factor for overall survival in multivariate analysis (hazard ratio, 3.99; 95% confidence interval, 1.26-12.61, P = 0.018).

CONCLUSIONS

Patients with higher AAPR had more favorable prognosis compared with patients with lower AAPR. We demonstrated that AAPR can be of prognostic value in well-differentiated NETs.

Basal and Calcium-Stimulated Procalcitonin for the Diagnosis of Medullary Thyroid Cancers: Lights and Shadows

BACKGROUND

Procalcitonin (proCt) was recently proposed as an alternative or in addition to calcitonin (Ct) in medullary thyroid cancer (MTC) diagnostics.

METHODS

Serum basal Ct (bCt) and proCt (bproCt) levels were measured before surgery from a consecutive series of patients with (n=43) and without (n=75) MTC, retrospectively collected in Padua. Serum bproCt, bCt and stimulated proCt and Ct (sproCt and sCt) were measured in another consecutive series of 33 patients seen at three tertiary-level institutions undergoing a calcium stimulation test prior to surgery, 20 of them with a final diagnosis of MTC, and 13 with non-MTC nodular disease.

RESULTS

Median bproCt levels were higher in MTC than in non-MTC. A positive correlation was found for bproCt with bCt (P<0.01, R² = 0.75), and with tumor size (P<0.01, R² = 0.39). The cut-off for bproCt differentiating between MTC and non-MTC patients was >0.07 ng/ml (sensitivity: 85.7%, specificity: 98.9%, positive predictive value [PPV]: 98.2%, negative predictive value [NPV]: 90.6%, P<0.01). While bproCt was >0.07 ng/ml in 38/39 (97.4%) patients with MTC >10 mm, it was above said cut-off only in 15/23 (65.2%) patients with tumors ≤10 mm. A sproCt >0.19 ng/ml was able to identify MTC [sensitivity: 90.0%, specificity:100.0%, PPV: 100.0%, NPV: 86.7% (P<0.01)].

CONCLUSIONS

Our data suggest that bproCt can be a good adjunct to Ct for MTC diagnostic purposes. In consideration of its high specificity, it can be used in combination with Ct in MTC diagnostics, particularly in the case of mildly elevated basal Ct levels.

Serum Calcitonin-Negative Medullary Thyroid Carcinoma: A Case Series of 19 Patients in a Single Center

INTRODUCTION

Medullary thyroid carcinoma (MTC) is a rare cancer that accounts for 5% of thyroid cancers. Serum calcitonin is a good biomarker for MTC, which is used for diagnosis, prognosis, and monitoring of recurrence. Calcitonin-negative MTC (CNMTC) is rare but confounds diagnostic and prognostic directions. This study introduces 19 cases of CNMTC in a single center.

METHOD

From 2002 March to 2020 July, more than 76,500 patients had undergone thyroid surgery due to thyroid cancer at the Severance Hospital, and a total of 320 patients were diagnosed with MTC (0.4%). Serum calcitonin levels were obtained from every patient who was suspected with MTC. These patients had undergone either bilateral total thyroidectomy or unilateral thyroidectomy with central compartment lymph node dissection, and additional modified radical lymph node dissection if lateral lymph node metastasis was positive. Postoperative monitoring and out-patient clinic follow-up were performed with obtaining the serum calcitonin levels.

RESULT

Nineteen patients tested negative for calcitonin preoperatively (6%). The mean preoperative calcitonin level was 5.1pg/mL if undetectable level is regarded as 0pg/mL. Only two patients were males, and the female bias was significant (p = 0.017). No one except two patients with modified radical neck dissection showed central compartment lymph node metastasis. Every patient's postoperative calcitonin level remained low. The median follow-up period was 71 months. There was no recurrence and only one fatality, and the overall survival rate was 95%.

CONCLUSION

Since incidence of CNMTC is not negligible, MTC should not be ruled out in the diagnostic phase even if serum calcitonin is negative in preoperative examination. We presented 19 cases of CNMTC whose prognosis in general were favorable. Markers of serum and immunohistochemical samples other than calcitonin should be actively examined.

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.

Untargeted longitudinal analysis of a wellness cohort identifies markers of metastatic cancer years prior to diagnosis

We analyzed 1196 proteins in longitudinal plasma samples from participants in a commercial wellness program, including samples collected pre-diagnosis from ten cancer patients and 69 controls. For three individuals ultimately diagnosed with metastatic breast, lung, or pancreatic cancer, CEACAM5 was a persistent longitudinal outlier as early as 26.5 months pre-diagnosis. CALCA, a biomarker for medullary thyroid cancer, was hypersecreted in metastatic pancreatic cancer at least 16.5 months pre-diagnosis. ERBB2 levels spiked in metastatic breast cancer between 10.0 and 4.0 months pre-diagnosis. Our results support the value of deep phenotyping seemingly healthy individuals in prospectively inferring disease transitions.

Elevated procalcitonin levels in primary hepatic neuroendocrine carcinoma: Case report and literature review

RATIONALE

Procalcitonin (PCT) has been identified as a tumor biomarker in medullary thyroid carcinoma. Other neuroendocrine carcinomas with elevated PCT levels are relatively rare, and are mainly reported in the lung, digestive tract, and pancreas. No studies in the literature have reported a case of primary hepatic carcinoma complicated with unexpectedly elevated PCT levels.

PATIENT CONCERNS

A 78-year-old man with persistent fatigue and mild fever was complicated with an extremely high PCT level. Radiological examination revealed a single hypodense lesion in the left lobe of the liver with a "rapid enhancement and rapid washout" pattern. Pathological analysis showed a poorly differentiated neuroendocrine carcinoma (grade 3) with multiple genetic mutations.

DIAGNOSIS

Primary hepatic neuroendocrine carcinoma.

INTERVENTIONS

The patient received antibiotic therapy and subsequent transcatheter hepatic arterial chemoembolization; a PCT assessment and computed tomography were performed during the follow-up.

OUTCOMES

The PCT level did not decline after antibiotic therapy but greatly declined in response to effective transcatheter hepatic arterial chemoembolization. The patient survived and is still being followed up.

LESSONS

An extremely elevated PCT level may raise a suspicion of a neuroendocrine carcinoma and plays an indicative role as a biomarker during therapy.

Calcitonin levels by ECLIA correlate well with RIA values in higher range but are affected by sex, TgAb, and renal function in lower range

Calcitonin (CT) is a marker for both initial diagnosis and monitoring of patients with residual or recurrent medullary thyroid carcinoma (MTC). In Japan, serum CT had been measured by radioimmunoassay (RIA) until recently. Electrochemiluminescence immunoassay (ECLIA) became commercially available in 2014, and this technique is now the only method used to examine CT concentration. The purposes of this study were to investigate the correlations between the CT concentration measured with ECLIA (ECLIA-CT) and RIA (RIA-CT) and to explore the clinical characteristics of patients with elevated ECLIA-CT. CT concentrations of 348 sera samples from 334 patients with various thyroid disorders including nine MTC were measured using both assays. The correlation analysis revealed an excellent correlation between ECLIA-CT and RIA-CT among the cases with CT level >150 pg/mL by both assays (r_s = 0.991, p < 0.001). However, 63% of all samples exhibited undetectable ECLIA-CT, while their RIA-CTs were measured between 15 and 152 pg/mL. The ECLIA-CTs in all patients who underwent total thyroidectomy for non-MTC showed low concentrations. High ECLIA-CT was observed in patients with MTC or pancreas neuroendocrine tumor. ECLIA-CT was also increased in 14 other male patients with non-MTC, including four with renal failure. Multivariate logistic regression analysis showed that male sex, negative TgAb, and lower estimated glomerular filtration rate were independent factors to predict detectable ECLIA-CT (≥0.500 pg/mL). These results indicate that ECLIA-CT correlates well with RIA-CT in higher range and is affected by sex, TgAb, and renal function.

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.

Importance of Complete Pathology Reporting for Neuroendocrine Carcinoma: WHO Guidelines Are a Good Start but Not Enough

BACKGROUND

Neuroendocrine carcinomas (NECs) are diagnosed through a combination of immunohistochemistry (IHC) and morphology according to WHO guidelines. The presence of these crucial components for classification in the pathology report is critical for appropriate understanding of the report especially since terminology and definitions of NEC have been changing a lot lately.

OBJECTIVES

The aim of this study is to assess the effect of WHO 2010 on the quality of pathology reporting for NEC and to assess the relevance of the criteria demanded.

METHODS

Patients registered with a NEC (gastrointestinal or unknown origin) in the Netherlands Cancer Registry (NCR) between 2008 and 2012 were included. Local pathology reports were reviewed for reporting of morphology and IHC comparing 2008-2010 (baseline) with 2011-2012. The diagnosis of NEC was confirmed according to WHO 2010, if synaptophysin or chromogranin were positive in a majority of cells and Ki-67 or mitotic count confirmed a grade 3 tumour.

RESULTS

591 patients were registered with a NEC in the NCR. 436 pathology reports were reviewed. 62.2% of reports described morphology, IHC and grading in accordance with WHO 2010. Reporting of these parameters increased from 50.0% in 2008 to 69.2% in 2012. Large-cell NEC could be confirmed in 45.0% of patients, increasing from 31.7% in 2008 to 56.7% in 2012 (p = 0.02). Other diagnoses included neuroendocrine tumour (NET) G1/2 13.3%, small-cell carcinoma 2.8%, no neuroendocrine neoplasm (NEN) 17.7%, NEN grade unknown 21.3%. Mean survival was 1.1 years in large cell NEC versus 2.2 years in NET G1/2 (p = 0.005).

CONCLUSION

Implementation of the WHO 2010 guideline is associated with a significant increase in reporting parameters needed for classification. Stratification of patients is more reliable based on reports containing all parameters. Guidelines alone however are not enough to warrant complete reporting; synoptic reports might be needed.

Variability in Medullary Thyroid Carcinoma in RET L790F Carriers: A Case Comparison Study of Index Patients

Background: Previous studies have suggested that the variability in age of onset and aggressiveness of medullary thyroid carcinoma (MTC) in patients with multiple endocrine neoplasia type 2A (MEN 2A) carrying the same REarranged during Transfection (RET) mutation may be caused by additional RET germline variants or somatic variants. Methods: This study was a retrospective case comparison study of all MEN 2A index patients (n = 2) with the RET L790F germline mutation in Denmark. Whole blood and MTC tissue were analyzed for RET germline variants and other somatic variants (>500), respectively. Results: Patient 1 presented with MTC (T1aN1bM0) at age 14 years, while patient 2 presented with MTC (T1bN0M0) at age 70 years. No germline RET germline variants nor other variants were found to explain this MTC variability. Conclusions: We could not confirm the previously reported finding of a somatic RET variant as likely responsible for the early onset and aggressiveness of MTC in a RET germline mutation carrier. Also, we found no RET germline variants that could explain the MTC variability among our index patients. We did, however, identify a somatic FLT3 R387Q variant with an unknown potential as genetic modifier. Further large-scale studies are needed to investigate genetic modifiers in RET L790F carriers.

F-18-Dopa Positron Emission Tomography/Computed Tomography Is More Sensitive Than Whole-Body Magnetic Resonance Imaging for the Localization of Persistent/Recurrent Disease of Medullary Thyroid Cancer Patients

Background: Elevated postoperative serum calcitonin (Ctn) level indicates persistent/recurrent disease in patients with medullary thyroid carcinoma (MTC). Its location is a challenge. The aim of our study was to compare the disease detection rates of F-18-Dopa (fluoro dihydroxyphenylalanine) positron emission tomography (PET)/computed tomography (CT), whole-body (WB) magnetic resonance imaging (MRI), F-18-FDG (fluorodeoxyglucose) PET/CT, WB CT scanning, neck ultrasonography, and bone scintigraphy in MTC patients with increased Ctn levels and unknown localization of the source. Methods: We compared the independent reading of each imaging procedure with a reference assessment for structural disease defined by pathology or concordance between two imagings or with subsequent follow-up. The detection rate of each imaging modality was determined in per patient, per organ, and per lesion analysis. Results: Thirty-six consecutive patients (21 females, mean age: 57 years, sporadic MTC in 26 cases, median serum Ctn level: 760 pg/mL; range: 21-10,121) were analyzed. The reference assessment localized disease in 24 (64%) patients with 74 lesions detected in the thyroid bed (8), in neck lymph nodes (15), mediastinal lymph nodes (6), lungs (1), liver (2), bones (3), and other site (1). At the patient level, the detection rates were 64% (CI 0.48-0.80) for F-18-Dopa PET/CT with early acquisitions, 40% (CI 0.24-0.56) for F-18-FDG PET/CT, 40% (CI 0.24-0.56) for WB MRI, and 48% (CI 0.31-0.66) for WB CT scan. Conclusions: In MTC patients with increased Ctn and no known distant metastases, F-18-Dopa PET/CT is more sensitive to detect structural disease than any other imaging modality, including WB MRI.

Diagnosis and pathologic characteristics of medullary thyroid carcinoma-review of current guidelines

Background

Medullary thyroid carcinoma (mtc) is a rare malignancy of the thyroid gland, and raising awareness of the recommended diagnostic workup and pathologic characteristics of this malignancy is therefore important.

Methods

We reviewed the current clinical practice guidelines and recent literature on mtc, and here, we summarize the recommendations for its diagnosis and workup. We also provide an overview of the pathology of mtc.

Results

A neuroendocrine tumour, mtc arises from parafollicular cells ("C cells"), which secrete calcitonin. As part of the multiple endocrine neoplasia (men) type 2 syndromes, mtc can occur sporadically or in a hereditary form. This usually poorly delineated and infiltrative tumour is composed of solid nests of discohesive cells within a fibrous stroma that might also contain amyloid. Suspicious nodules on thyroid ultrasonography should be assessed with fine-needle aspiration (fna). If a diagnosis of mtc is made on fna, patients require baseline measurements of serum calcitonin and carcinoembryonic antigen. Calcitonin levels greater than 500 pg/mL or clinical suspicion for metastatic disease dictate the need for further imaging studies. All patients should undergo dna analysis for RET mutations to diagnose men type 2 syndromes, and if positive, they should be assessed for possible pheochromocytoma and hyperparathyroidism.

Summary

Although the initial diagnosis of a suspicious thyroid nodule is the same for differentiated thyroid carcinoma and mtc, the remainder of the workup and diagnosis for mtc is distinct.

Low-serum prostate-specific antigen level predicts poor outcomes in patients with primary neuroendocrine prostate cancer

BACKGROUND

The rarities of primary neuroendocrine prostate cancer (NEPC) and primary adenocarcinoma with neuroendocrine differentiation (NE differentiation) mean that their clinical characteristics have not been fully elucidated.

MATERIALS AND METHODS

A total of 449 patients with NEPC, including 352 cases of pure NEPC and 97 cases of NE differentiation, together with 408 629 cases of prostate adenocarcinoma at diagnosis were retrieved from the Surveillance, Epidemiology, and End Results program (2010-2015). Clinical parameters and prognoses were compared between patients with different histological types of NEPC using the χ² test and Kaplan-Meier analysis, respectively. The prognostic value of prostate-specific antigen (PSA) in NEPC and adenocarcinoma was evaluated using Cox regression and the Kaplan-Meier method.

RESULTS

Pure NEPC had higher rates of visceral metastases (brain, lung, and liver: 4.58%, 26.72%, and 36.64%, respectively) but a lower rate of bone metastasis (65.65%) compared with NE differentiation and prostate adenocarcinoma. Moreover, patients diagnosed with pure NEPC had a poorer outcome (median survival time: 10 months) compared with patients with NE differentiation (26 months) and prostate adenocarcinoma (median survival time not reached). Using PSA 4.1 to 10 ng/mL as the reference, the adjusted hazard ratios (HRs) for PSA lower than or equal to 4.0 ng/mL were 2.24 (95% confidence interval [CI]: 1.11-4.55, P = .025) in the NE differentiation group and 1.57 (95% CI: 1.11-2.23, P = .011) in the pure NEPC group.

CONCLUSIONS

Patients with NE differentiation had different clinical characteristics and a better prognosis than patients with pure NEPC. In addition, low-serum PSA levels were associated with a poorer prognosis in patients with either NEPC or NE differentiation.

Fifty Years After the First Description, MEN 2B Syndrome Diagnosis Is Still Late: Descriptions of Two Recent Cases

BACKGROUND

Multiple endocrine neoplasia type 2B (MEN 2B) is a very rare syndrome characterized by a very peculiar phenotype with mucosal neuromas, marfanoid habitus, and bumpy lips associated with medullary thyroid cancer (MTC) and pheochromocytoma (PHEO). Although the syndrome was first described 50 years ago, it is still diagnosed too late, when the MTC is metastatic and frequently when the PHEO has already developed.

CASE PRESENTATIONS

We report on two cases of MEN 2B that were diagnosed too late, preventing a cure. The cases involve two females who were 25 and 12 years old. Both were previously treated for congenital skeletal abnormalities; however, despite their bumpy lips and mucosal neuromas, MEN 2B syndrome was not recognized. When they arrived at our center for both the presence of thyroid nodules and elevated serum calcitonin values, the MTC was already metastatic, and the older patient had already developed a bilateral PHEO. After 3 years and 1 year of follow-up, the two patients are still alive but with persistent structural and biochemical disease.

DISCUSSION

These two cases show that knowledge of this syndrome is still insufficient and that the lack of knowledge impairs the ability to obtain an early diagnosis and cure. Because most patients with MEN 2B have no familial history, the only way to ensure a timely diagnosis is to recognize the MEN 2B phenotype on a clinical basis.

Calcitonin negative Medullary Thyroid Carcinoma: a challenging diagnosis or a medical dilemma?

BACKGROUND

Medullary thyroid carcinoma is a neuroendocrine tumor belonging form a malignant growth of the thyroid parafollicular C-cells, representing from 1 to 10% of all thyroid cancer. The biochemical activity of medullary thyroid carcinoma includes the production of calcitonin and carcinoembryogenic antigen, which are sensitive tumor markers, facilitating the diagnosis, follow-up and prognostication. The diagnosis is reached through the identification of high basal calcitonin serum level or after pentagastrin stimulation test. Medullary thyroid carcinoma is able to produce other relevant biomarkers as procalcitonin, carcinoembryionic antigen and chromogranin A. In Literature are described few cases of medullary thyroid carcinoma without elevation of serum calcitonin, an extremely rare event. The aim of this study was to analyse the presentation, the main features and therapeutic management of medullary thyroid carcinoma associated with negative serum calcitonin levels.

METHODS

Using the PubMed database, a systematic review of the current Literature was carried out, up to February 2018. Finally, nineteen articles met our inclusion criteria and were selected according to the modified Newcastle-Ottawa scale.

RESULTS

Fourty-nine patients with definitive pathology confirming medullary thyroid carcinoma and with calcitonin serum level in the normal range were identified (24 female, 24 male and not reported gender in 1 case). Mean age was 51.7 years. Serum calcitonin levels were reported for 20 patients with a mean value of 8.66 pg/mL and a range of 0.8-38 pg/mL. Despite the low or undetectable calcitonin serum level, at immunochemistry in almost the half of the cases reported by the Authors, the tumors presented diffuse or focal positivity for calcitonin and carcinoembryionic antigen, while was reported a chromogranin A positivity in 41 of the 43 tested patients.

CONCLUSIONS

Calcitonin negative medullary thyroid carcinoma is an extremely rare pathology. The diagnosis and the surveillance is often challenging and delayed, due to the lack of elevation of serum markers as calcitonin and carcinoembryionic antigen. Further studies are needed, to better define options for management of non secretory medullary thyroid carcinoma and to identify new and reliable biomarkers associated to diagnosis and relapse of this medical dilemma.

[Routine serum calcitonin measurement in thyroid nodules]

There is much controversy about the benefits of the use of serum calcitonin (CT) in the initial evaluation of patients with thyroid nodules. The objective of the study was to early identify medullary thyroid carcinoma (MTC) through the routine measurement of CT in thyroid nodular pathology in a large cohort of patients from Buenos Aires, Argentina. Consecutive patients with nodular thyroid disease (n=1017) were studied. CT was measured by chemiluminescence, normal value: up to 18 pg/ml in men and 12 pg/ml in women. In two patients, hypercalcitoninemia was confirmed in repeated measurements. Fine needle aspiration with CT measurement in the needle wash fluid identified MTC in nodules with citology abnormalities. The genetic study was positive in one patient (mutation exon 14, Val804Met, MTC familiar). The other presented a polymorphism (exon 13 L769L heterozygous - exon 15 S904S heterozygous). In both cases, CT was normalized 3 months after surgery and remained normal after 6 years of follow-up. The routine measurement of CT in thyroid nodular pathology was useful to detect two cases of MTC, one of them sporadic and the other familiar in this cohort. The prevalence of MTC was 0.2%.

Serum level of dipeptidyl peptidase-4 as a potential biomarker for medullary thyroid cancer

AIM

Adipokines are the proteins secreted from adipose tissue and play an important role in the control of metabolism. Dipeptidyl peptidase-4 (DPP4) is a novel adipokine with different biological role. As indicated by various studies, serum levels of DPP4 had been associated with body mass index (BMI), insulin resistance, metabolic syndrome and malignancy. The aim of this study was to assess the serum levels of DPP4 in patients with medullary thyroid cancer (MTC) in comparison with these in the control group.

MATERIALS AND METHODS

This study was performed on 45 MTC patients (24 females and 21 males) and 45 healthy controls (21 females and 24 males). DPP4 and insulin serum levels were measured by ELISA, fasting glucose serum levels by enzyme-calorimetric method and insulin resistance index (HOMA-IR) by calculation using relevant equation. BMI (kg/m2) was also calculated.

RESULTS

Our data did not demonstrate a significant difference between serum DPP4 levels in MTC and healthy group (41.06 ± 22.08 ng/ml vs 39.94 ± 20.77 ng/ml, p > 0.05). Additionally, no significant difference was found in serum insulin and HOMA-IR concentrations between MTC patients and the controls (p > 0.05).

CONCLUSIONS

This study suggests that the fluctuation in the levels of DPP4 does not play an important role in prognosis, early detection and diagnosis of MTC. Furthermore, higher levels of DPP4 cannot be considered as a risk factor for MTC.

Medullary Thyroid Carcinoma: Prognostic Variables And Tumour Markers Affecting Survival

BACKGROUND

Medullary thyroid carcinoma (MTC) is a relatively rare thyroid malignancy and its clinical course varies among patients due to its familial association. A number of prognostic factors have been studied, but the significance of these factors remains controversial. We evaluated the progression free survival (PFS) and overall survival (OS) of MTC and its association with tumour marker rising velocity and serum calcitonin (Ct) doubling time (DT).

METHODS

Analysis of 83 (8.7%) consecutive MTC patients registered at a single centre between 1995 and 2015. The impact of tumour respectability, TNM stage, multiple endocrine neoplasia (MEN) syndrome, local recurrence, Ct DT and Ct rising velocity on PFS and OS was analysed. Median follow-up was 4.3 years (range: 1-18 years).

RESULTS

Eighty-three (8.7%) of all thyroid cancers registered at our centre were MTC. Fifty-five males, 28 females. Mean age 39 years [range: 17-72 years]. Twenty-two were unresectable and 61 resectable. Five-year and 10-year OS was 84% and 77% respectively. Of 68 with follow up greater than a year; 20 (29.4%) were cured, 15 (22.1%) had biochemical evidence of disease, three (4.4%) had stable macroscopic disease and 30 (44.1%) had recurrent/progressive disease. Sixteen (23.5%) died. On multivariate analysis, T4 tumour, male gender, nodal and distant metastases, tumour resectibility, Ct DT less than two years and tumour marker rising velocity of greater than 0.05pg/ml/month were poor prognostic factors (pvalue <0.05). Age and association with MEN syndrome had no statistically significant survival impact. Radiotherapy reduced local relapse in patients with nodal disease. Total thyroidectomy with nodal clearance lessened relapses.

CONCLUSION

Clinical stage and pathological aspects are predictors of disease progression. Persistent biochemical evidence of MTC does not affect OS, however, Ct DT < 2 years and rapid rate of tumour marker rise predict disease progression.

Esophageal neuroendocrine carcinoma complicated with unexpected hyperprocalcitonin: Case report and literature review

RATIONALE

Neuroendocrine tumors (NETs) with hyperprocalcitonin are relatively rare with a low incidence rate.

PATIENT CONCERNS

An afebrile 63-year-old male with persistent low back pain unexpectedly presented with an extreme hyperprocalcitonin. Radiological assessment revealed thickening of the esophageal wall with vertebral bone destruction and liver lesions. Endoscopy showed an irregular-shaped esophageal lesion which turned out to be poorly-differentiated NETs.

DIAGNOSIS

Esophageal NETs with multiple metastases.

INTERVENTIONS

The patient was treated with chemotherapies, and was evaluated by procalcitonin level and radiology within follow-up.

OUTCOME

The procalcitonin levels were altered in line with the therapeutic response and disease progression during the treatment course.

LESSONS

Increased procalcitonin occurs in several malignancies with neuroendocrine components, such as NETs of the digestive system.

CALCITONIN SECRETORY INDEX AND UNSUSPECTED NODAL DISEASE IN MEDULLARY THYROID CARCINOMA

OBJECTIVE

Medullary thyroid carcinoma (MTC) is a rare thyroid malignancy originating from parafollicular C-cells with the potential for aggressive behavior. The extent of lymph node (LN) dissection at the time of surgery is controversial, with different schools of thought prevailing. Some systematically perform LN dissections, whereas others base their decision on radiologic evidence of disease and some with the assistance of pre-operative calcitonin (CT) levels.

METHODS

We retrospectively assessed the correlation between pre-operative CT levels and clinico-pathologic factors among 42 patients with MTC between 1994 and 2015. Furthermore, we refined the use of pre-operative serum CT levels and explored for the first time a test called the Calcitonin Secretory Index (CSI, ng/mL/mm).

RESULTS

Pre-operative CT levels correlated independently with tumor size ( P<.0001), number of metastatic LNs ( P<.01), and increased rates of distant metastasis. The CSI better predicted early LN disease ( P<.045). Patients with early LN metastasis had a CSI >30 ng/mL/mm, a representative threshold above which the surgical cure declines considerably.

CONCLUSION

In our experience, pre-operative CT levels and now the CSI appear as sensitive and specific risk stratification markers for MTC. Despite negative findings on dedicated pre-operative neck imaging in addition to total thyroidectomy, a CSI >30 ng/mL/mm would prompt bilateral central node dissection. Due to the small sample size, our study provides preliminary evidence of the value of CSI in clinical practice.

ABBREVIATIONS

ANOVA = analysis of variance; ATA = American Thyroid Association; CSI = Calcitonin Secretory Index; CT = calcitonin; LN = lymph node; MTC = medullary thyroid carcinoma; ROC = receiver operating characteristic.

Circulating miR-375 as a novel prognostic marker for metastatic medullary thyroid cancer patients

This study aimed to identify circulating miRNAs as novel non-invasive biomarkers for prognosis and vandetanib response in advanced medullary thyroid cancer (MTC) patients. We prospectively recruited two independent cohorts of locally advanced/metastatic MTC patients including a subgroup of vandetanib-treated subjects: a discovery cohort (n = 20), including matched plasma/tissue samples (n = 17/20), and a validation cohort, yielding only plasma samples (n = 17). Plasma samples from healthy subjects (n = 36) and MTC patients in remission (n = 9) were used as controls. MTC (n = 17 from 8 patients included in discovery cohort) and non-neoplastic thyroid specimens (n = 3) were assessed by microarray profiling to identify candidate circulating miRNAs. qRT-PCR and in situ hybridization were carried out to validate the expression and localization of a selected miRNA within tissues, and qRT-PCR was also performed to measure miRNA levels in plasma samples. By microarray analysis, we identified 51 miRNAs differentially expressed in MTC. The most overexpressed miR, miR-375, was highly expressed by C cells compared to other thyroid cells, and more expressed in MTC than in reactive C-cell hyperplasia. MTC patients had significantly higher miR-375 plasma levels than healthy controls (P < 0.0001) and subjects in remission (P = 0.0004) as demonstrated by qRT-PCR analysis. miR-375 plasma levels were not predictive of vandetanib response, but, notably, high levels were associated with significantly reduced overall survival (HR 10.61, P < 0.0001) and were a strong prognostic factor of poor prognosis (HR 6.24, P = 0.00025) in MTC patients. Overall, our results unveil plasma miR-375 as a promising prognostic marker for advanced MTC patients, to be validated in larger cohorts.

Measurement of Basal Serum Calcitonin for the Diagnosis of Medullary Thyroid Cancer

Calcitonin (CT), a tumor marker for medullary thyroid cancer (MTC), can be stimulated with pentagastrin or calcium. Because of the unavailability of pentagastrin, basal CT measurement is frequently used for the preoperative diagnosis of MTC. The aim of the study was to define basal serum calcitonin (bCT) cut-off thresholds for diagnosing MTC. Within a retrospective analysis, 114 patients (51 males) were included fulfilling the criteria of an increased preoperative bCT level (>10 pg/ml) and the criteria of an available postoperative histology analysis. Based on a ROC plot analysis, the cut-off values for the diagnosis of MTC vs. non-malignancy (C cell hyperplasia and goiter) were identified. The most precise bCT thresholds for the identification of MTC were ≥46 pg/ml for males (sensitivity: 93.6%, specificity: 95.0%, PPV: 97%, NPV: 90%) and ≥35 pg/ml for females (sensitivity: 87.3%, specificity: 87.5%, PPV: 98%, NPV: 50%). Using these cut-offs, only 6% of male patients were not identified of having MTC, whereas 5% were false positive (having instead C cell hyperplasia). In females, the discrepancy was higher since 13% of female MTC patients were false negative by using the cut-off of ≥35 pg/ml, and 13% had false positive results (suffering from C cell hyperplasia). Gender-specific bCT cut-offs for the identification of MTC vs. C cell hyperplasia and non-malignancy were defined, which can be used in clinical routine. In female patients, however, the accuracy is much lower compared to males.

Preclinical Evaluation of AdVince, an Oncolytic Adenovirus Adapted for Treatment of Liver Metastases from Neuroendocrine Cancer

Cancer immunotherapy is becoming a cornerstone in the clinical care of cancer patients due to the breakthrough trials with immune checkpoint blockade antibodies and chimeric antigen receptor T cells. The next breakthrough in cancer immunotherapy is likely to be oncolytic viruses engineered to selectively kill tumor cells and deceive the immune system to believe that the tumor is a foreign entity that needs to be eradicated. We have developed AdVince, an oncolytic adenovirus for treatment of liver metastases from neuroendocrine tumor (NET). AdVince includes the gene promoter from human chromogranin A for selective replication in neuroendocrine cells, miR122 target sequences for reduced liver toxicity, and a cell-penetrating peptide in the capsid for increased infectivity of tumor cells and optimized spread within tumors. This paper describes the preclinical evaluation of AdVince on freshly isolated human gastrointestinal NET cells resected from liver metastases and freshly isolated human hepatocytes as well as in fresh human blood. AdVince selectively replicates in and kills NET cells. Approximately 73-fold higher concentration of AdVince is needed to induce a similar level of cytotoxicity in NET cells as in hepatocytes. AdVince did not activate complement or induce considerable amount of proinflammatory cytokines or chemokines in human blood. The data presented herein indicate that AdVince can be safely evaluated in a phase I/IIa clinical trial for patients with liver-dominant NET.

Long-Term Follow-Up and Treatment of Postoperative Permanent Hypoparathyroidism in Patients with Medullary Thyroid Carcinoma: Differences in Complete and Partial Disease

This study aimed to identify factors influencing long-term outcome in complete or partial postoperative hypoparathyroidism (parathyroid hormone ≤10 or >10 ng/l, respectively) in medullary thyroid carcinoma (MTC). It was designed as retrospective, long-term follow-up with single-center outpatient visits. Quality of treatment, renal calcification, and function were evaluated. In 33 patients with MTC and postoperative hypoparathyroidism, current medication includes: calcium (73%), calcitriol (73%), alfacalcidol (6%), dihydrotachysterol (3%), and cholecalciferol supplements (21%). Mean hypoparathyroidism duration was 15.9±9.4 years. Initially, 15% of patients received high cholecalciferol dosages. Initial calcium dosages were higher (1 542±1 179 mg/day) than final dosages (1 188 ± 595 mg/day) (p<0.05); calcitriol dosages remained constant. Over the median observation period of about 12 years it was found that serum calcium was within the target range (2.0-2.3 mmol/l) in 63% of visits, decreased (<2.0 mmol/l) in 20.4%, high-normal (2.4-2.6 mmol/l) in 15.8%, and increased (>2.65 mmol/l) in 0.9% of visits. Calcitriol dosages were 0.73±0.22 μg/day and 0.47±0.20 μg/day in patients with complete (n=13) and partial (n=20) hypoparathyroidism, respectively (p=0.008). Renal function decreased slightly during follow-up (eGFR: 102±22 vs. 90±27 ml/min). eGFR was negatively correlated with hypoparathyroidism duration (r=-0.35, p=0.05). Of 9 patients with renal calcification, 5 had received high initial cholecalciferol doses. eGFR was lower in patients with than in those without calcification (77±17 vs. 95±29 ml/min) (p=0.07). At least one tetanic episode occurred in 60.6% of patients, and 9% had repeated tetanic complaints. In conclusion, severity of hypoparathyroidism affects treatment: Partial hypoparathyroidism required lower calcitriol dosages than complete hypoparathyroidism. Renal calcifications occurred more frequently in patients treated initially with high cholecalciferol dosages. Impaired renal function was related to hypoparathyroidism duration and renal calcification.

Analytical Performance of a Gene Expression Classifier for Medullary Thyroid Carcinoma

BACKGROUND

The aim of this study was to demonstrate the analytical validity of an RNA classifier for medullary thyroid carcinoma (MTC).

METHODS

Fresh-frozen tissue specimens were obtained from commercial sources, and MTC diagnoses were confirmed by histopathology review. De-identified patient fine-needle aspiration biopsies (FNABs) and whole blood from normal donors were obtained. Total RNA was extracted, amplified, and hybridized to custom microarrays for gene expression analysis. Gene expression data were normalized and classified via a machine learning algorithm. Positive control materials were produced from MTC tissues and tested across multiple experiments and laboratories. Twenty-seven MTC tissue specimens were used to evaluate the sensitivity of the MTC classifier. Gene expression data from tissues and FNABs were used to model classifier response to mixtures of MTC samples with normal thyroid tissue, a benign thyroid nodule, a Hürthle cell adenoma, and whole blood. Select mixture conditions were confirmed in vitro. Assay tolerance to RNA input variation (5-25 ng) and genomic DNA contamination (30% by mass) was evaluated. The intra- and inter-run reproducibility and inter-laboratory accuracy of MTC classifier results were characterized.

RESULTS

The MTC classifier sensitivity of 96.3% [confidence interval 81.0-99.9%] was determined retrospectively using 27 MTC confirmed tissue specimens. One false-negative result in a necrotic tissue implicated sample necrosis in reduced classifier sensitivity. Dilution modeling of MTC samples with normal or benign tissues showed consistent detection of MTC down to 20% sample proportions, with in vitro confirmation of 20% analytical sensitivity. Classifier tolerance to RNA input variation (5-25 ng), genomic DNA contamination (30% by mass), and an interfering substance (blood) was demonstrated with 100% accurate classifier results under all tested conditions. The maximum observed run-to-run score difference for a single FNAB sample was ∼1 unit compared with the average score difference between 38 MTC and non-MTC FNABs of ∼32 units. MTC classifier results for 20 tissues processed from total RNA in two different laboratories showed 100% concordance.

CONCLUSIONS

The MTC classifier, offered as part of the routine molecular testing of cytology-indeterminate thyroid nodules, demonstrates robust analytical sensitivity, specificity, accuracy, and reproducibility.

Reference values of serum calcitonin with calcium stimulation tests by electrochemiluminescence immunoassay before/after total thyroidectomy in Japanese patients with thyroid diseases other than medullary thyroid carcinoma

Calcitonin is a very sensitive tumor marker of medullary thyroid carcinoma (MTC). MTC patients usually have very high values of serum calcitonin that can be used to diagnose the disease. To improve the diagnostic sensitivity in family members with small MTCs and to evaluate the postoperative biochemical cure status, a calcium stimulation test is widely used. Serum calcitonin has been measured using several methods, but in Japan, only an electrochemiluminescence immunoassay (ECLIA) is currently performed to determine serum calcitonin. Reference values for the calcium stimulation test using an ECLIA have not been reported. Here we conducted a calcium stimulation tests in 26 patients without MTC before and after total thyroidectomy. Preoperatively, the basal calcitonin values of all patients were within normal limits and increased to a mean of 14.4 pg/mL after calcium stimulation. We transformed the peak values before total thyroidectomy to a logarithmic distribution and calculated the normalized mean ± 1.96× standard deviation; the reference upper limit was thus expressed. In the female patients with non-MTC, the reference upper limit was 67.6 pg/mL. In all patients, the calcium stimulation test results after total thyroidectomy showed undetectable basal and stimulated calcitonin values (<0.5 pg/mL). This is the first study to determine reference values to be used for the calcium stimulation test along with an ECLIA in non-MTC patients. We propose that female patients are regarded as biochemically cured or normal when the stimulated calcitonin values by ECLIA are <67.6 pg/mL before surgery and <0.5 pg/mL after total thyroidectomy.

Calcitonin doubling time in medullary thyroid carcinoma after the detection of distant metastases keenly predicts patients' carcinoma death

Therapy using tyrosine-kinase inhibitors (TKIs) is now available for recurring or advanced medullary thyroid carcinoma (MTC). Here we investigated the calcitonin doubling time (Ct-DT) of MTC patients with distant recurrence postoperatively and for those with distant metastasis at the initial surgery. Of the 13 patients, six died due to the MTC at 5-93 months after the detection of distant metastasis. Their Ct-DTs were ≤ 1.58 years. The remaining seven patients have been alive for 73-123 months after the detection of metastasis, and their Ct-DTs were low at -4, -2.25 years and 9.17-33.92 years. Similar results were obtained by analyzing the value of 1/Ct-DT to avoid discontinuity in the DT values among the patients with increasing serum Ct values over time and those with decreasing Ct values over time. These findings suggest that it is appropriate to use TKIs only for patients with a short Ct-DT and a large 1/Ct-DT with a cutoff at around 1.5 years and 0.67/year, respectively, even if they have distant metastases.

Serum calcitonin negative medullary thyroid carcinoma: a systematic review of the literature

Generally, calcitonin (CT) values below the upper reference limit rule-out medullary thyroid carcinoma (MTC) with very high accuracy. However, sparse cases of serum-calcitonin-negative MTC (CT-NEG-MTC) have been reported. Here we reviewed CT-NEG-MTC reported in literature, discussed the potential causes and proposed a practical laboratory and clinical approach. A comprehensive literature search was conducted by using the terms "medullary thyroid carcinoma" AND "non-secreting calcitonin" OR "undetectable calcitonin". The search was updated until December 2014. Original articles that described CT-NEG-MTC were eligible for inclusion. Only MTC cases with preoperative CT below the upper reference limit were included in the present review. Eleven papers with 18 CT-NEG-MTC cases (age 50 years, size 26 mm) were retrieved. Four patients with poorly differentiated MTC died within 3 years. Different CT assays were employed and different reference values were adopted. Preoperative serum CT values were below the institution cut-off levels in all cases, and undetectable in four patients. In some papers negative CT results were confirmed by additional tests. Further laboratory investigations were performed in some of the included studies. In patients with well founded suspicious of MTC and within the reference limits/undetectable CT other laboratory investigations [carcinoembryonic antigen (CEA), procalcitonin, CT stimulation, CT in washout of nodule's aspiration] have to be performed. Surgical approach to CT-NEG-MTC does not differ from those secreting CT. Postoperative follow-up of these rare cases should include periodical imaging and measurement of all potential markers. Patients with poorly differentiated MTC are at higher risk of disease-related death, and require more aggressive follow-up strategy.

Dynamic risk stratification for medullary thyroid cancer according to the response to initial therapy

Detecting persistent/recurrent disease of medullary thyroid carcinoma (MTC) is important. The tumor-node-metastasis (TNM) staging system is useful for predicting disease-specific mortality, but is a static system and does not include postoperative serum calcitonin levels. We have focused on the clinical usefulness of dynamic risk stratification (DRS) using the best response to the initial therapy in MTC patients. A total of 120 MTC patients were classified into three DRS groups based on their responses to initial therapy. Clinical outcomes were assessed according to TNM staging and DRS. In the DRS, 70, 23 and 7 % of the MTC patients were classified into excellent, biochemical incomplete, or structural incomplete response groups, respectively. On TNM staging, 37, 16, 13 and 35 % of patients were stages I-IV, respectively. There were significant differences in survivals according to TNM staging (p = 0.03) and DRS (p = 0.005). During the median follow-up of 6.2 years, 75 patients (63 %) demonstrated no evidence of disease (NED). About 60 and 17 % of patients in stages III and IV were NED, respectively. DRS predicted NED better than TNM staging according to the proportion of variance explained (PVE) (49.1 vs. 28.7 %, respectively). At the final follow-up, 88, 4 and 0 % of patients in excellent, biochemical incomplete, and structural incomplete response groups attained NED, respectively. DRS based on the best response to the initial therapy can provide useful prognostic information in addition to initial TNM staging for predicting of mortality, as well as the likelihood of NED in MTC patients.

Usefulness of Serum Calcitonin in Patients Without a Suspicious History of Medullary Thyroid Carcinoma and with Thyroid Nodules Without an Indication for Fine-Needle Aspiration or with Benign Cytology

This study evaluated the usefulness of serum calcitonin (Ctn) in subjects without a suspicious history of medullary thyroid carcinoma (MTC) and with nodular thyroid disease without an indication for fine-needle aspiration (FNA) or with benign cytology. This was a prospective study that evaluated 421 patients with nodular disease without an indication for FNA and 602 patients with benign cytology. Patients with basal Ctn>10 pg/ml were submitted to calcium stimulation testing. Patients with stimulated Ctn>100 pg/ml were submitted to total thyroidectomy. Basal Ctn was<10 pg/ml in 1001 patients (97.8%). Among patients with basal Ctn>10 pg/ml, 16/22 exhibited stimulated Ctn>100 pg/ml. Two of these 16 patients had MTC. The 2 patients with MTC had undetectable basal Ctn 6 months after surgery. Using a cut-off of 30 pg/ml in women and 60 pg/ml in men for basal Ctn, the 2 cases of MTC of our series would have been identified and there would have been no false-positive case. It should be noted that 14/16 patients with stimulated Ctn>100 pg/ml were false-positive cases. Although uncommon, even subjects without a suspicious history and with nodular thyroid disease without an indication for FNA or with benign cytology can have MTC. The measurement of Ctn permits the diagnosis of these cases. Our results favor the hypothesis that basal Ctn could be superior to stimulated Ctn.

Postoperative biochemical remission of serum calcitonin is the best predictive factor for recurrence-free survival of medullary thyroid cancer: a large-scale retrospective analysis over 30 years

CONTEXT

The increase in thyroid screening in the general population may lead to earlier detection of medullary thyroid carcinoma (MTC).

OBJECTIVE

We aimed to evaluate secular trends in clinicopathological characteristics and long-term prognosis of MTC and its prognostic factors.

DESIGN

This was a retrospective analysis from 1982 to 2012.

PATIENTS

Three hundred and thirty-one patients with MTC were included and grouped based on the year of diagnosis (1982-2000, 2001-2005, 2006-2010 and 2011-2012).

MEASUREMENTS

These included recurrence and mortality as well as biochemical remission (BCR) of serum calcitonin.

RESULTS

Mean tumour size (from 2·5 cm to 1·7 cm, P < 0·001) and percentage of extrathyroidal extension (from 52·0% to 26·0%, P = 0·026) decreased. The percentage of patients achieving BCR within six postoperative months (po-BCR) increased with time (from 39·6% to 76·1%, P < 0·001). The 5-year overall recurrence rate significantly decreased in 2006-2012 compared to 1982-2005 (10% vs 18%, respectively, P = 0·031), although the 5-year survival rate did not improve (92% vs 92%, P = 0·929). Failure to achieve po-BCR was the strongest predictive factor associated with recurrence (hazard ratio [HR] = 58·04, 95% CI 7·14-472·11; P < 0·001). Male gender (HR = 3·18, 95% CI 1·18-8·56; P = 0·022), tumour size >2 cm (HR = 18·33, 95% CI 2·35-143·06; P = 0·006) and distant metastasis (HR = 4·00, 95% CI 1·31-12·21; P = 0·015) were significant prognostic factors for mortality.

CONCLUSIONS

Clinicopathological characteristics and recurrence of MTC improved with time. Po-BCR was the best predictive factor for recurrence-free survival.

Macrocalcitonin Is a Novel Pitfall in the Routine of Serum Calcitonin Immunoassay

CONTEXT

Calcitonin (CT) is a sensitive marker of medullary thyroid carcinoma (MTC) and is used for primary diagnosis and follow-up after thyroidectomy. However, persistently elevated CT is observed even after complete surgical removal without evidence of a recurrent or persistent tumor.

OBJECTIVE

To investigate the presence of assay interference in the serum CT of MTC patients who are apparently without a structural disease.

PATIENTS AND METHODS

We studied three index MTC cases for CT assay interference and 14 patients with metastatic MTC. The CT level was measured using an immunofluorometric assay. Screening for assay interference was performed by determination of CT levels before and after serum treatment with polyethylene glycol. Additionally, samples were analyzed by chromatography on ultra-performance liquid chromatography and protein A-Sepharose.

RESULTS

Patients with biochemical and structural disease showed CT mean recovery of 84.1% after polyethylene glycol treatment, whereas patients suspected of interference showed recovery from 2-7%. The elution profile on UPLC showed that the immunometric CT from these three patients behaved like a high molecular mass aggregate (>300 kDa). Additionally, when these samples were applied to the protein A-Sepharose, CT immunoreactivity was retained on the column and was only released after lowering the pH.

CONCLUSIONS

For the first time, our results show the presence of a novel pitfall in the CT immunoassay: "macrocalcitonin." Its etiology, frequency, and meaning remain to be defined, but its recognition is of interest and can help clinicians avoid unnecessary diagnostic investigations and treatment during the follow-up of MTC.

A Phase II Trial of the Multitargeted Tyrosine Kinase Inhibitor Lenvatinib (E7080) in Advanced Medullary Thyroid Cancer

PURPOSE

Positive results of phase I studies evaluating lenvatinib in solid tumors, including thyroid cancer, prompted a phase II trial in advanced medullary thyroid carcinoma (MTC).

EXPERIMENTAL DESIGN

Fifty-nine patients with unresectable progressive MTC per Response Evaluation Criteria In Solid Tumors (RECIST) v1.0 within the prior 12 months received lenvatinib (24-mg daily, 28-day cycles) until disease progression, unmanageable toxicity, withdrawal, or death. Prior anti-VEGFR therapy was permitted. The primary endpoint was objective response rate (ORR) by RECIST v1.0 and independent imaging review.

RESULTS

Lenvatinib ORR was 36% [95% confidence interval (CI), 24%-49%]; all partial responses. ORR was comparable between patients with (35%) or without (36%) prior anti-VEGFR therapy. Disease control rate (DCR) was 80% (95% CI, 67%-89%); 44% had stable disease. Among responders, median time to response (TTR) was 3.5 months (95% CI, 1.9-3.7). Median progression-free survival (PFS) was 9.0 months (95% CI, 7.0-not evaluable). Common toxicity criteria grade 3/4 treatment-emergent adverse events included diarrhea (14%), hypertension (7%), decreased appetite (7%), fatigue, dysphagia, and increased alanine aminotransferase levels (5% each). Ret proto-oncogene status did not correlate with outcomes. Low baseline levels of angiopoietin-2, hepatocyte growth factor, and IL8 were associated with tumor reduction and prolonged PFS. High baseline levels of VEGF, soluble VEGFR3, and platelet-derived growth factor BB, and low baseline levels of soluble Tie-2, were associated with tumor reduction.

CONCLUSIONS

Lenvatinib had a high ORR, high DCR, and a short TTR in patients with documented progressive MTC. Toxicities were managed with dose modifications and medications.

Ultrasonographic Features of Medullary Thyroid Carcinoma: Do they Correlate with Pre and PostOperative Calcitonin Levels?

PURPOSE

To correlate ultrasonographic (US) features of medullary thyroid carcinoma (MTC) with pre operative and postoperative calcitonin levels.

MATERIALS AND METHODS

A total of 130 thyroid nodules diagnosed as MTC were evaluated. Two radiologists retrospectively evaluated preoperative US features according to size, shape, margin, echogenicity, type of calcification, and lymph node status. Postoperative clinical and imaging followup (mean duration 31.9 ± 22.5 months) was performed for detection of tumor recurrence. US features, presence of LN metastasis, and tumor recurrence were compared between MTC nodules with and without elevated preoperative calcitonin (>100 pg/mL). Those with normalized and nonnormalized postoperative calcitonin levels groups were also compared.

RESULTS

Common US features of MTCs were solid internal content (90.8%), irregular shape (44.6%), circumscribed margin (46.2%), and hypoechogenicity (56.2%). Comparing MTC nodules with and without elevated preoperative calcitonin levels, the size and shape of MTC nodule and lymph node metastasis showed statistical significance (p<0.05). Postoperative calcitonin normalization correlated with US features of tumor size (p=0.002), margin (p=0.034), shape (p≤0.001), and presence of calcification (p=0.046). Tumor recurrence and LN metastasis were more prevalent in patients without normalization of postoperative calcitonin than in those with normalization (p=0.001).

CONCLUSIONS

Serum calcitonin measurement is helpful for early diagnosis and predicting prognosis. Postoperative calcitonin measurement is also important for postoperative US follow up, especially in cases with larger nodule size, presence of calcification, irregular shape, and irregular margin.

Lack of Association between Serum Adiponectin/Leptin Levels and Medullary Thyroid Cancer

BACKGROUND

Adipokines are bioactive proteins that mediate metabolism, inflammation and angiogenesis. Changes in the secretion of key serum adipokines - adiponectin and letpin - may be associated with obesity, cancer and metabolic disorders. Thyroid cancer is one of the most important types of endocrine cancer. Therefore, investigating the association between serum levels of adiponectin and leptin and thyroid cancer might be important. The purpose of this study was to assess adiponectin and leptin levels in medullary thyroid carcinoma (MTC) cases in order to identify novel tumor markers.

MATERIALS AND METHODS

This research was based on a case-control study, including 45 patients with medullary thyroid cancer (21 men and 24 women) and 45 healthy controls (24 males and 21 females). Adiponectin and leptin levels were measured by ELISA in both groups. Height and weight were measured and body mass index (kg/m2) was calculated.

RESULTS

Adiponectin and leptin levels were not significantly different between medullary thyroid carcinomas and the control group. Also, there was no correlation among age and body mass index and the disease.

CONCLUSIONS

These results suggest that changes in serum adiponectin and leptin levels do not play an important role in the diagnosis or could act as as biomarkers for medullary thyroid cancer.

Integration of a postoperative calcitonin measurement into an anatomical staging system improves initial risk stratification in medullary thyroid cancer

OBJECTIVE

Staging systems applied to medullary thyroid cancer (MTC) rely on initial clinical and pathological features and do not consider the response to treatment. To determine whether MTC staging can be improved by incorporating the first postoperative calcitonin measurement.

PATIENTS AND MEASUREMENTS

Eighty-five patients being monitored for MTC (median follow-up 5 years) were retrospectively classified according to both the American Joint Committee on Cancer (AJCC) and the proposed combined risk stratification system (low, intermediate and high risk), which incorporates the first postoperative calcitonin measurement, using the outcomes no evidence of disease (NED), biochemical evidence of disease, structurally identifiable disease and death.

RESULTS

Ninety per cent of AJCC I patients were classified as NED at final follow-up. When we added a postoperative calcitonin measurement, 95% low-risk patients were classified as NED at final follow-up. AJCC stages I and IV were associated, respectively, with no occurrence and a high rate (63%) of structurally identifiable disease. Stages II and III yielded similar predictions of structurally identifiable disease, 13% and 14%, respectively. When we included the postoperative calcitonin level, the patients with structural evidence of disease included none from the low-risk group, 10% from the intermediate group and 63% from the high-risk group. The proportion of variance explained analysis (PVE) was better for the combined risk stratification system (54%) than for the AJCC system alone (32%).

CONCLUSION

Including the first postoperative calcitonin measurement with the anatomical staging system can better predict the clinical outcome of patients with MTC and refine the follow-up of these patients.

Prognostic Value of Serum Tumor Markers in Medullary Thyroid Cancer Patients Undergoing Vandetanib Treatment

Tyrosine kinase inhibitors (TKIs) such as vandetanib have shown clinical effectiveness in advanced medullary thyroid cancer (MTC). During TKI treatment, fluctuations in the tumor markers carcinoembryonic antigen (CEA) and calcitonin (CTN) are frequently observed. Their role for treatment monitoring and the decision-making process has not been fully elucidated yet.Twenty-one patients (male, 16, female, 5; mean age, 49 ± 13 years) with progressive MTC receiving vandetanib (300 mg orally per day) were considered. Tumor restaging was performed every 3 months including contrast-enhanced computed tomography (CT). Response was assessed according to recent criteria (Response Evaluation Criteria in Solid Tumors, RECIST 1.1). Additionally, CEA and CTN were measured at the day of CT imaging and alterations observed in tumor markers were compared to respective imaging findings (partial response, PR; stable disease, SD; progressive disease, PD).During long-term follow-up (510 ± 350 days [range, 97-1140 days]), CTN and CEA levels initially dropped in 71.4% and 61.9% of the patients followed by fluctuations in serum marker levels. A rise in CTN ≥39.5% between 2 subsequent measurements (defined by ROC analysis) had a sensitivity of 70.6% and a specificity of 83.2% in predicting PD with an accuracy of 82.0% (area under the curve (AUC), 0.76). Oscillations in CEA levels were not predictive for PD.Whereas tumor marker fluctuations in MTC patients undergoing TKI treatment are a frequent phenomenon, a significant rise in CTN ≥40% turns out to as an early indicator of tumor progression.

Serum Thyroglobulin Measured With a Second-Generation Assay in Patients Undergoing Total Thyroidectomy Without Radioiodine Remnant Ablation: A Prospective Study

BACKGROUND

Follow-up consisting of the measurement of nonstimulated serum thyroglobulin (Tg) combined with neck ultrasonography is recommended for patients with papillary thyroid carcinoma without indication for radioiodine ablation. There is no recommendation of thyrotropin suppression during this follow-up. New-generation Tg assays have been increasingly used, but few studies involve patients submitted only to thyroidectomy and they have several limitations. The objective of this prospective study was to define expected concentrations of nonstimulated Tg measured with a second-generation assay after total thyroidectomy in the absence of tumor.

METHODS

Serum Tg was measured using a second-generation assay in 69 patients without tumor and serum thyrotropin between 0.5 and 2 mIU/L, 3, 6, 12, and 24 months after total thyroidectomy. All patients had undetectable anti-Tg antibodies.

RESULTS

Serum Tg was undetectable in 44.4%, 57%, 62.5%, and 62.1% of the patients 3, 6, 12, and 24 months after thyroidectomy, respectively, and was ≤0.5 ng/mL in 60.3%, 80%, 90.6%, and 90.9% of patients. All patients had a Tg≤2 ng/mL 6 months after thyroidectomy, and 97% had a Tg≤1 ng/mL 24 months after surgery. There was no case of Tg conversion from undetectable to detectable and none of the patients presented an increase in Tg.

CONCLUSIONS

An important decline in serum Tg occurred between 3 and 6 months after total thyroidectomy. One year after surgery, Tg was undetectable in approximately 60% of the patients and was ≤2 ng/mL in all of them.

Procalcitonin for detecting medullary thyroid carcinoma: a systematic review

The aim of the present study was to perform a systematic review of published studies to provide a robust estimation of the use of procalcitonin (ProCT) as a diagnostic marker of medullary thyroid carcinoma (MTC), with particular focus on its specificity and negative predictive value in excluding MTC. A comprehensive computer literature search was conducted to find relevant published articles on the topic. We used a search algorithm based on a combination of the terms 'medullary,' 'thyroid,' and 'ProCT.' The search was updated until February 2015. To expand our search, references of the retrieved articles were also screened. A total of 39 articles were retrieved, of which nine original papers published from 2003 to 2014 were selected for the review. Some of these studies used ProCT in the preoperative diagnosis of MTC, whereas others measured ProCT during the follow-up of patients who had been previously treated for MTC. Other laboratory measurements were performed in some of the included studies. The results of the majority of the studies indicate that ProCT measurement appears to be a very promising and reliable serum marker for the diagnosis of MTC, and it is not inferior to calcitonin (CT). The sample handling is less laborious, and in the few CT-negative cases reviewed, the assay had even greater sensitivity. It would be worthwhile to establish cutoff levels using larger patient series, because we speculate that this assay could potentially replace CT measurement in the future.

Long-Term Follow-up in Medullary Thyroid Carcinoma

After surgery, patients with medullary thyroid carcinoma (MTC) should be assessed regarding the presence of residual disease, the localization of metastases, and the identification of progressive disease. Postoperatively, patients with MTC are staged to separate those at low risk from those at high risk of recurrence. The TNM staging system is based on tumor size, extra-thyroidal invasion, nodal metastasis, and distant spread of cancer. In addition, the number of lymph-node metastases, the number of compartments involved, and the postoperative calcitonin (CTN) and carcinoembryonic antigen (CEA) levels should be documented. The postoperative normalization of the serum CTN level is associated with a favorable outcome. When patients have basal serum CTN levels less than 150 pg/ml after a thyroidectomy, any persistent or recurrent disease is nearly always confined to lymph nodes in the neck. When the postoperative serum CTN level exceeds 150 pg/ml, patients should be evaluated with imaging procedures, including computed tomography (CT) of the neck and chest, contrast-enhanced magnetic resonance imaging (MRI) and ultrasound (US) of the liver, bone scintigraphy, MRI of the bone, and positron emission tomography (PET)/CT. One can estimate the growth rate of MTC metastases by quantifying increases in tumor size over time from sequential imaging studies analyzed with response evaluation criteria in solid tumors (RECIST), and by determining the tumor marker doubling time from sequential measures of serum CTN or CEA levels over multiple time points. One of the main challenges remains to find effective adjuvant and palliative options for patients with metastatic disease. Patients with persistent or recurrent MTC localized to the neck following thyroidectomy are candidates for neck operations, depending on the tumor extension. Once metastases appear, the clinician must decide which patients require therapy. This requires a balance between the (often) slow rate of tumor progression, which is associated with a good quality of life, and the limited efficacy and potential toxicities of local and systemic therapies. Considering that metastatic MTC is incurable, the management goals are to provide loco-regional disease control, palliate symptoms of hormonal excess, such as diarrhea, palliate symptomatic metastases, like pain or bone fracture, and control metastases that threaten life, such as bronchial obstruction or spinal cord compression. This can be achieved with palliative surgery, external beam radiation therapy (EBRT), or systemic therapy with tyrosine kinase inhibitor (TKI).

Ectopic calcitonin secretion in a woman with large cell neuroendocrine lung carcinoma

OBJECTIVE

Serum calcitonin (CT) is a sensitive but not specific marker for medullary thyroid carcinoma (MTC). There are a large number of conditions that may elevate CT levels.

CASE REPORT

Herein we present the case of a 47-year old woman with Hashimoto thyroiditis, goiter, cervical lymphadenopathy and high CT and CEA levels. After surgical extirpation of the lymph node neuroendocrine cancer metastasis was suspected. Computed tomography of the chest showed a tumor mass on the right lung. Bronchoscopy was performed and pathological and immunohistochemical analysis revealed large cell neuroendocrine lung cancer (LCNEC). After chemotherapy, significant reduction of tumor mass was achieved with a moderate decrease in CT levels in parallel.

CONCLUSIONS

We present a female with LCNEC, a condition which is usually observed in older men (7(th) decade) and is not associated with CT secretion. Hashimoto thyroiditis is associated with increased incidence of different types of cancers (e.g. thyroid, colon). No reports at present exist on the incidence of lung cancers in patients with thyroid disease.

Gastric neuroendocrine carcinoma with non-islet cell tumor hypoglycemia associated with enhanced production of insulin-like growth factor II

A 75-year-old man was admitted to the hospital with a loss of consciousness. His blood glucose level was 24 mg/dL. Abdominal computed tomography revealed multiple metastatic lesions in the liver, while upper endoscopy disclosed advanced gastric cancer. The hypoglycemia was refractory despite the administration of glucose and steroid therapy. The patient died within one month of admission. An autopsy revealed neuroendocrine-type gastric cancer, which, on examination with immunohistochemistry, was found to be negative for insulin and insulin-like growth factor I and positive for insulin-like growth factor II (IGF-II). The patient was diagnosed as having gastric cancer with non-islet cell tumor hypoglycemia (NICTH) caused by IGF-II.