Medullary thyroid carcinoma: long-term outcomes of surgical treatment

Time Kinetics and prognosis roles of calcitonin after surgery for medullary thyroid carcinoma

BACKGROUND

Medullary thyroid carcinoma (MTC) is a malignant tumor with low incidence. Currently, most studies have focused on the prognostic risk factors of MTC, whatever, time kinetic and risk factors related to calcitonin normalization (CN) and biochemical persistence/recurrence (BP) are yet to be elucidated.

METHODS

A retrospective study was conducted for 190 MTC patients. Risk factors related to calcitonin normalization (CN) and biochemical persistence/recurrence (BP) were analyzed. The predictors of calcitonin normalization time (CNT) and biochemical persistent/recurrent time (BPT) were identified. Further, the prognostic roles of CNT and BPT were also demonstrated.

RESULTS

The 5- and 10-year DFS were 86.7% and 70.2%, respectively. The 5- and 10-year OS were 97.6% and 78.8%, respectively. CN was achieved in 120 (63.2%) patients, whereas BP was presented in 76 (40.0%) patients at the last follow up. After curative surgery, 39 (32.5%) and 106 (88.3%) patients achieved CN within 1 week and 1 month. All patients who failed to achieve CN turned to BP over time and 32/70 of them developed structural recurrence. The median time of CNT and BPT was 1 month (1 day to 84 months) and 6 month (3 day to 63months), respectively. LNR > 0.23 and male gender were independent predictors for CN and BP. LNR > 0.23 (Hazard ratio (HR), 0.24; 95% CI,0.13-0.46; P < 0.01) and male gender (HR, 0.65; 95% CI, 0.42-0.99; P = 0.045) were independent predictors for longer CNT. LNR > 0.23 (HR,5.10; 95% CI,2.15-12.11; P < 0.01) was still the strongest independent predictor followed by preoperative serum Ctn > 1400ng/L (HR,2.34; 95% CI,1.29-4.25; P = 0.005) for shorter BPT. In survival analysis, primary tumor size > 2 cm (HR, 5.81; 95% CI,2.20-15.38; P < 0.01), CNT > 1 month (HR, 5.69; 95% CI, 1.17-27.61; P = 0.031) and multifocality (HR, 3.10; 95% CI, 1.45-6.65; P = 0.004) were independent predictor of DFS.

CONCLUSION

Early changes of Ctn after curative surgery can predict the long-term risks of biochemical and structural recurrence, which provide a useful real-time prognostic information. LNR significantly affect the time kinetic of biochemical prognosis. Tumor burden and CNT play a crucial role in MTC survival, the intensity of follow-up must be tailored accordingly.

Risk factors for cervical lymph node metastasis in the central or lateral cervical region in medullary thyroid carcinoma: a systematic review and meta-analysis

PURPOSE

Compared with other types of thyroid carcinoma, patients with medullary thyroid carcinoma (MTC) are more likely to develop cervical lymph node metastasis. This study was conducted to clarify the risk factors for cervical lymph node metastasis (central lymph node metastasis or lateral cervical lymph node metastasis) in MTC by meta-analysis, and to provide evidence-based basis for the treatment and prognosis of MTC.

METHODS

The literatures related to cervical lymph node metastasis in medullary thyroid carcinoma were searched in PubMed, Embase, Web of Science, Cochrane, CNKI and Wanfang databases, and statistical analysis was performed using Revman 5.3 and Stata 14.0 software.

RESULTS

A total of 28 papers were included in this paper, and meta-analysis showed that the occurrence of central lymph node metastasis (CLNM) in MTC patients was significantly associated with tumor size (OR = 3.07, 95%CI: 2.04-4.63, P < 0.00001), multifocality (OR = 0.29, 95%CI: 0.19-0.44, P < 0.00001), bilaterality (OR = 3.75, 95% CI: 1.95-7.14, P < 0.0001), capsular invasion (OR = 9.88, 95% CI: 5.93-16.45, P < 0.00001) and extrathyroidal extension (OR = 5.48, 95% CI: 2.61-11.51, P < 0.00001). While the occurrence of lateral cervical lymph node metastasis (LLNM) in MTC patients was strongly correlated with gender (OR = 2.97, 95%CI: 2.46-3.58, P < 0.00001), tumor size (OR = 3.88, 95%CI: 1.90-7.92, P = 0.0002 < 0.05), multifocality (OR = 0.43, 95%CI: 0.35-0.51, P < 0.00001), bilaterality (OR = 2.93, 95% CI: 1.72-4.98, P < 0.0001), capsular invasion (OR = 8.44, 95% CI: 6.11-11.64, P < 0.00001), extrathyroidal extension (OR = 7.04, 95% CI: 5.54-8.94, P < 0.00001), margin of the tumor (OR = 4.47, 95% CI: 2.37-8.44, P < 0.00001), shape of the tumor (OR = 6.81, 95% CI: 3.64-12.73, P < 0.00001), preoperative calcitonin level (SMD = 1.39, 95% CI: 0.98-1.80, P < 0.00001), preoperative carcinoembryonic antigen level (SMD = 0.97, 95% CI: 0.74-1.20, P < 0.00001) and CLNM (OR = 19.70, 95% CI: 14.16-27.43, P < 0.00001).

CONCLUSION

Tumor size, multifocality, bilaterality, capsular invasion and extrathyroidal extension are the main risk factors for developing CLNM in MTC patients; And risk factors for developing LLNM in MTC patients include: gender, tumor size, multifocality, bilaterality, capsular invasion, extrathyroidal extension, margin of the tumor, shape of the tumor, preoperative calcitonin level, preoperative carcinoembryonic antigen level and central lymph node metastasis. These risk factors can guide the individualized treatment plan and improve the prognosis of MTC patients.

Update on C-Cell Neuroendocrine Neoplasm: Prognostic and Predictive Histopathologic and Molecular Features of Medullary Thyroid Carcinoma

Medullary thyroid carcinoma (MTC) is a C-cell-derived epithelial neuroendocrine neoplasm. With the exception of rare examples, most are well-differentiated epithelial neuroendocrine neoplasms (also known as neuroendocrine tumors in the taxonomy of the International Agency for Research on Cancer [IARC] of the World Health Organization [WHO]). This review provides an overview and recent evidence-based data on the molecular genetics, disease risk stratification based on clinicopathologic variables including molecular profiling and histopathologic variables, and targeted molecular therapies in patients with advanced MTC. While MTC is not the only neuroendocrine neoplasm in the thyroid gland, other neuroendocrine neoplasms in the thyroid include intrathyroidal thymic neuroendocrine neoplasms, intrathyroidal parathyroid neoplasms, and primary thyroid paragangliomas as well as metastatic neuroendocrine neoplasms. Therefore, the first responsibility of a pathologist is to distinguish MTC from other mimics using appropriate biomarkers. The second responsibility includes meticulous assessment of the status of angioinvasion (defined as tumor cells invading through a vessel wall and forming tumor-fibrin complexes, or intravascular tumor cells admixed with fibrin/thrombus), tumor necrosis, proliferative rate (mitotic count and Ki67 labeling index), and tumor grade (low- or high-grade) along with the tumor stage and the resection margins. Given the morphologic and proliferative heterogeneity in these neoplasms, an exhaustive sampling is strongly recommended. Routine molecular testing for pathogenic germline RET variants is typically performed in all patients with a diagnosis of MTC; however, multifocal C-cell hyperplasia in association with at least a single focus of MTC and/or multifocal C-cell neoplasia are morphological harbingers of germline RET alterations. It is of interest to assess the status of pathogenic molecular alterations involving genes other than RET like the MET variants in MTC families with no pathogenic germline RET variants. Furthermore, the status of somatic RET alterations should be determined in all advanced/progressive or metastatic diseases, especially when selective RET inhibitor therapy (e.g., selpercatinib or pralsetinib) is considered. While the role of routine SSTR2/5 immunohistochemistry remains to be further clarified, evidence suggests that patients with somatostatin receptor (SSTR)-avid metastatic disease may also benefit from the option of ¹⁷⁷Lu-DOTATATE peptide radionuclide receptor therapy. Finally, the authors of this review make a call to support the nomenclature change of MTC to C-cell neuroendocrine neoplasm to align this entity with the IARC/WHO taxonomy since MTCs represent epithelial neuroendocrine neoplasms of endoderm-derived C-cells.

External Validation of Three Available Grading Systems for Medullary Thyroid Carcinoma in a Single Institution Cohort

Medullary thyroid carcinoma (MTC) is a rare thyroid carcinoma with a variable clinical behavior. Potential clinical and pathological prognostic markers have been investigated, but studies are limited and controversial. In neuroendocrine neoplasms of various other sites, necrosis and proliferation (mitotic activity and/or Ki67 index) are integrated to provide a histological grade. Recently, an International Medullary Thyroid Carcinoma Grading System (IMTCGS) has been designed to define high- or low-grade MTC by combining proliferative activity and necrosis. This proposal integrates two previously published grading schemes by American (2-tiered grading, low- and high-grade MTC) and Australian authors (3-tiered grading, low-, intermediate-, and high-grade MTC). To validate the clinical role of these systems, their prognostic impact was evaluated in an independent cohort of 111 MTCs. Necrosis, which was the only parameter integrated into the 3 grading systems, proved to be individually correlate with tumor relapse, while no association was found with the proliferation (mitotic count and Ki67 index); however, by combining the different parameters according to all three grading systems, "high-grade" MTCs turned out to be significantly associated with the disease recurrence (p < 0.005) in all systems. In disease-free survival analysis, the IMTCGS stratification was the only one that demonstrated a significant impact at Cox regression analysis (p = 0.004), further confirmed by the Kaplan-Meier curves (p = 0.002). Similar findings were also reproduced when analysis was restricted to sporadic MTCs (68 cases). In conclusion, our results confirm the prognostic role of IMTCGS, supporting the importance of incorporating this information into the pathology report. However, none of the systems proved to predict the overall survival in this validation cohort.

Long-Term Outcomes and Causes of Death among Medullary Thyroid Carcinoma Patients with Distant Metastases

Distant metastasis is a poor prognostic factor in medullary thyroid carcinoma (MTC), but the significance of differentiating the characteristics according to the site of distant metastasis remains unclear. This study aimed to evaluate the clinical characteristics and long-term oncologic outcomes in MTC patients with distant metastasis. We identified 46 MTC patients with distant metastasis between 1994 and 2019. Clinical characteristics were compared based on the timing of the detection of distant metastasis. Additionally, survival rates following the detection of distant metastasis were evaluated to compare the clinical significance of metastatic site. The detailed causes of death were also investigated. Of the 46 patients, 15 patients (32.6%) had synchronous distant metastasis and 31 patients (67.4%) had metachronous distant metastasis. There was no clinical difference between these two groups except regarding initial surgical extent. The lung (52.2%) was the most common metastatic site, followed by the bone (28.3%), mediastinum (19.6%), liver (17.4%), adrenal gland (4.3%), brain (4.3%), kidney (2.2%), and pancreas (2.2%). Patients with bone metastasis and multisite metastasis had significantly worse prognoses than those with lung metastasis (hazard ratio: 5.42; p = 0.044 and hazard ratio: 6.11; p = 0.006). Complications due to the progression of distant metastasis, airway obstruction due to tracheal invasion, and complications related to chemotherapy were leading causes of death. In conclusion, there was no difference in clinical characteristics according to the timing of distant metastasis. Oncological outcomes differed by metastatic site.

Similar Stage-dependent Survival and Outcome in Sporadic and Hereditary Medullary Thyroid Carcinoma

CONTEXT

Long-term data are scarce on large cohorts with sporadic (sMTC) and hereditary medullary thyroid carcinoma (hMTC).

OBJECTIVES

To compare long-term disease-specific survival (DSS) and outcomes between sMTC and hMTC groups.

DESIGN

Retrospective analysis.

SETTING

German tertiary referral center.

PATIENTS

A total of 673 patients with MTC that underwent surgery from January 1974 to July 2019.

INTERVENTION

None (observational study).

MAIN OUTCOME MEASURE

Differences between sMTC and hMTC in long-term, stage-dependent survival and outcomes.

RESULTS

Surgery was performed at median ages of 49 years for sMTC (n = 477, 44% male) and 29 years for hMTC (n = 196, 43% male; P < 0.0001). The mean follow-up times were 9.2 ± 8.0 (sMTC) and 14.6 ± 10.3 years (hMTC). Age and tumor stage at diagnosis were significantly different between the 2 groups (P < 0.0001). The sMTC and hMTC groups had different overall DSS (log rank, P = 0.0183), but similar stage-dependent DSS (log rank, P = 0.1242-0.8981). In a multivariate analysis, sMTC and hMTC did not differ in DSS (hazard ratio [HR] = 1.56; 95% CI, 0.94-2.57), but in both groups, a worse DSS was significantly associated with age at diagnosis (HR = 1.04; 95% CI, 1.02-1.05), male sex (HR = 0.49; 95% CI, 0.32-0.76), and stages III and IV at diagnosis (HR = 20.00; 95% CI, 2.74-145.91 and HR = 97.47; 95% CI, 13.07-726.67, respectively). The groups had significantly different (P < 0.0001) outcomes (i.e., cured, minimal residual disease, structural detectable disease, and death), but similar stage-dependent outcomes (P = 0.9449-0.0511), except for stage III (P = 0.0489).

CONCLUSION

Patients with sMTC and hMTC had different ages of onset, but similar stage-dependent DSS and outcomes after the MTC diagnosis. This finding suggested that tumor behavior was similar in sMTC and hMTC.

RET gene mutation analysis and long-term clinical outcomes of medullary thyroid cancer patients

OBJECTIVE

Medullary thyroid carcinoma is a rare, potentially aggressive tumour, with relatively worse prognosis than well-differentiated thyroid cancer. We evaluated the long-term outcomes and prognosis of medullary thyroid carcinoma patients at a single institution in India and compared outcomes based on results of RET protooncogene mutation analysis.

METHODS

Data were retrieved through a prospectively maintained thyroid cancer database from 1998 to June 2019, and medullary thyroid carcinoma patients were recruited. RET gene mutation status (exon 10-16) was assessed. Patient with a minimum follow-up of 12 months was eligible to be part of the long-term outcome analysis.

RESULTS

Out of 149 peripheral blood samples, 42 were positive for RET gene mutation (prevalence of 28.1%). The median follow-up duration was 48 months, ranging from 12 to 240 months. Long-term clinical outcomes of 113 patients were assessed. Two deaths were noted in this series. Both 5- and 10-year survival was cent per cent. Overall survival was 98.2% (97.3% in RET positive and 98.7% in RET negative group). Progression-free survival was 55.4% in total (60% in RET positive and 53.3% in RET negative group). No statistically significant difference was found between RET positive and RET negative groups concerning overall survival (P = 0.6011) and progression-free survival (P = 0.5140). Univariate analysis revealed high calcitonin (>10 pg/mL), stage IV disease, and presence of lymph nodal metastasis to be significant predictors of disease recurrence, however, multivariate analysis demonstrated the presence of lymph node metastases as the only significant predictor of recurrence (P = 0.0005).

CONCLUSIONS

Medullary thyroid carcinoma patients had relatively favourable long-term outcomes. Long-term survival was similar irrespective of RET mutation status. Presence of lymph node metastases appeared to be the strongest predictor of overall and progression-free survival, followed by Calcitonin level and stage of the disease.

Immune Co-inhibitory Receptors PD-1, CTLA-4, TIM-3, LAG-3, and TIGIT in Medullary Thyroid Cancers: A Large Cohort Study

CONTEXT

Programmed cell death protein-1 (PD-1), cytotoxic T-lymphocyte antigen 4 (CTLA-4), T-cell immunoglobulin and mucin-domain containing-3 (TIM-3), lymphocyte activation gene-3 (LAG-3), and T-cell immunoglobulin and ITIM domain (TIGIT) are considered major immune co-inhibitory receptors (CIRs) and the most promising immunotherapeutic targets in cancer treatment, but they are largely unexplored in medullary thyroid carcinoma (MTC).

OBJECTIVE

We aimed to provide the first evidence regarding the expression profiles and clinical significance of CIRs in a large cohort of MTC patients.

DESIGN AND PATIENTS

In total, 200 MTC patients who received initial surgery in our hospital were included. Immunohistochemistry was performed to evaluate CIR expressions in tissue microarrays (TMAs). Combined with the results of our previous programmed cell death ligand-1 (PD-L1) study, clinicopathologic and prognostic correlations of these proteins were retrospectively analyzed.

RESULTS

TIM-3, PD-1, CTLA-4, LAG-3, and TIGIT positivity was detected in 96 (48.0%), 27 (13.5%), 25 (12.5%), 6 (3.0%), and 6 (3.0%) patients, respectively, in whom TIM-3, PD-1, and CTLA-4 expressions were positively correlated. Log-rank tests and multivariate Cox analyses both indicated that TIM-3, CTLA-4 expression, and PD-1/PD-L1 coexpression were associated with worse structural recurrence-free survival. In addition, among 20 patients who developed advanced disease during follow-up, 12 (60%) showed TIM-3 positivity, among whom 6 cases also had concurrent moderate to strong PD-1, PD-L1, or CTLA-4 expression.

CONCLUSIONS

Using the currently largest TMA cohort of this rare cancer, we delineated the CIR expression profiles in MTC, and identified TIM-3, CTLA-4 expression, and PD-1/PD-L1 coexpression as promising biomarkers for tumor recurrence. Furthermore, a subset of advanced MTCs are probably immunogenic, for which single or combined immunotherapy including TIM-3, PD-1, PD-L1, or CTLA-4 blockade may be potential therapeutic approaches in the future.

A Proposed Grading Scheme for Medullary Thyroid Carcinoma Based on Proliferative Activity (Ki-67 and Mitotic Count) and Coagulative Necrosis

We investigated the prognostic value of a range of histologic parameters in medullary thyroid carcinoma (MTC) to design a grading system to predict overall survival. We assessed 76 patients with MTCs undergoing primary tumor resection for age, sex, tumor size, vascular space invasion, lymph node metastasis, multiple endocrine neoplasia type 2 (MEN2) status, mitotic count, Ki-67 proliferative index, spindled morphology, sheet-like growth pattern, coagulative necrosis, incipient necrosis, nuclear grade, multinucleation, prominent nucleoli, fibrosis, and amyloid deposition. In addition to the clinical features of age and the diagnosis of MEN2, the only histologic features that significantly predicted reduced overall survival were Ki-67 proliferative index, mitotic count, and the presence of coagulative necrosis. Using a combination of these 3 variables, we propose a 3-tiered grading system based solely on proliferative activity (Ki-67 proliferative index and mitotic count) and necrosis. There were 62 (82%) low-grade MTCs (low proliferative activity, no necrosis), 9 (12%) intermediate grade (low proliferative activity and necrosis present, or intermediate proliferative activity and no necrosis), and 5 (7%) high grade (intermediate proliferative activity and necrosis present, or high proliferative activity with or without necrosis). The mean overall survival was 193, 146, and 45 months, respectively (P=0.0001) for the 3 grades. The grading system remained prognostic when controlled for other factors associated with survival including age and known MEN2 syndrome. We conclude that this proposed grading system, which uses only a combination of proliferative activity (Ki-67 index, mitotic count) and coagulative necrosis, is a strong predictor of overall survival in MTC.

Role of tissue and circulating microRNAs and DNA as biomarkers in medullary thyroid cancer

Medullary thyroid carcinoma (MTC) is a rare neuroendocrine tumor comprising hereditary or sporadic form with frequent mutations in the rearranged during transfection (RET) or RAS genes. Diagnosis is based on the presence of thyroid tumor mass with altered levels of calcitonin (Ctn) and carcinoembryonal antigen (CEA) in the serum and/or in the cytological smears from fine needle aspiration biopsies. Treatment consists of total thyroidectomy, followed by tyrosine kinase inhibitors (TKi) in case of disease persistence. During TKi treatment, Ctn and CEA levels can fluctuate regardless of tumor volume, metastasis or response to therapy. Research for more reliable non-invasive biomarkers in MTC is still underway. In this context, circulating nucleic acids, namely circulating microRNAs (miRNAs) and cell free DNA (cfDNA), have been evaluated by different research groups. Aiming to shed light on whether miRNAs and cfDNA are suitable as MTC biomarkers we searched three different databases, PubMed, Scopus, WOS and reviewed the literature. We classified 83 publications fulfilling our search criteria and summarized the results. We report data on miRNAs and cfDNA that can be evaluated for validation in independent studies and clinical application.

Long-term Clinicopathological Features of a Family with Multiple Endocrine Neoplasia Type 2A Caused by C634R RET Gene Mutation

Type 2 multiple endocrine neoplasia (MEN2A) is a variant of hereditary medullary thyroid carcinoma (MTC). MEN2A is characterized by the presence of the following: MTC, hyperparathyroidism, and pheochromocytoma (PHEO). The pathogenesis includes RET proto-oncogene mutation; the most frequently observed mutation is in exon 11 codon 634. We report pedigree of a large Indian family involving three generations including 21 members with MEN2A, in whom RET mutation status was determined. We then analyzed their clinical follow-up details, with a median duration of follow-up of 60 months (range: 9-276 months). Calcitonin (Ctn) levels were routinely checked during the follow-up. The index case was found to carry p.C634R mutation involving exon 11 of the RET gene. RET mutation was positive in 12 members in the family (12/21, i.e., 57%), was negative in 7 patients, and was not tested in 2 patients, as they were not available for the genetic test. Thirteen were clinically affected with MTC and 10 members had PHEO. At the last follow-up, the median Ctn level was 14.3 pg/mL (range: 2-12655 pg/mL). Four patients developed lymph nodal recurrence during follow-up, for which they underwent re-operations with median duration to recurrence being 48 months (range: 9-156 months). We highlight in this article that early diagnosis, adequate surgery, and appropriate genetic counseling with genetic screening are essential to improve the outcome of persons with MTC. Every case of MTC should be seen as familial or index case of hereditary MTC unless otherwise RET mutation excludes it.

Risk Factors Associated With Reoperation and Disease-Specific Mortality in Patients With Medullary Thyroid Carcinoma

Importance

The association of initial neck dissection with recurrence in medullary thyroid carcinoma (MTC) has not been evaluated on a population level to date.

Objective

To elucidate risk factors associated with reoperation in MTC and disease-specific mortality.

Design, Setting, and Participants

A retrospective analysis was performed of hospital data obtained from the California Cancer Registry and the Office of Statewide Health Planning and Development from January 1, 1999, through December 31, 2012. The dates of the analysis were January 1, 1999, to December 31, 2012. A population-based sample of 953 patients with MTC was identified. Patients who underwent thyroid surgery and had a minimum postoperative follow-up of 2 years (n = 609) were included in the analysis.

Exposure

Initial neck dissection in MTC.

Main Outcomes and Measures

Recurrent MTC leading to reoperation and disease-specific mortality.

Results

Of the 609 patients with MTC who underwent thyroid surgery, the mean (SD) patient age at diagnosis was 52.6 (17.5) years, and 60.8% (n = 370) of the patients were female. The mean (SD) tumor size was 2.8 (2.0) cm. Although initial central neck dissection is recommended by published MTC guidelines, only 35.5% (216 of 609) of patients underwent central neck dissection at the time of the initial thyroidectomy. The rate of reoperation was 16.3% (99 of 609), and the median time to reoperation was 6.4 months. The presence of lymph node metastasis increased the risk of reoperation (hazard ratio [HR], 3.43; 95% CI, 2.00-5.90), while central and lateral neck dissection performed at the initial operation was protective (HR, 0.53; 95% CI, 0.30-0.93). In patients who underwent reoperation, 45.5% (45 of 99) were disease free at a median follow-up of 7.7 years. Five-year disease-specific mortality for the entire cohort was 13.5% (82 of 609). Independent risk factors for disease-specific mortality included older age (HR, 1.36 per decade; 95% CI, 1.17-1.59), tumor size greater than 2 cm (HR, 2.83; 95% CI, 1.08-7.44 for >2 to 4 cm and HR, 2.89; 95% CI, 1.09-7.71 for >4 cm), and regional (HR, 4.77; 95% CI, 2.29-9.94) and metastatic (HR, 21.08; 95% CI, 9.90-44.89) disease. Reoperation was not associated with increased mortality.

Conclusions and Relevance

Lymph node dissection may decrease recurrence leading to reoperation for patients with MTC. Reoperation is a viable strategy to achieve long-term disease-free survival in appropriately selected patients. Central neck dissection remains underused.

Clinico-pathologic and dynamic prognostic factors in sporadic and familial medullary thyroid carcinoma: an Israeli multi-center study

OBJECTIVE

Multiple clinical, pathological and biochemical variables, including the response to initial treatment, are associated with medullary thyroid carcinoma (MTC) prognosis. Studies that include separate analyses of familial and sporadic MTC patients followed for long period are scarce. This study evaluated the association between baseline clinico-pathologic variables and response to initial treatment and short- and long-term disease outcomes in sporadic and familial MTC.

METHODS

Patients treated for MTC at four tertiary medical centers were retrospectively analyzed. Clinical and pathological data were collected. The outcomes measured included disease persistence 1 year after diagnosis, disease persistence at last follow-up, disease-related mortality (DRM) and all-cause mortality.

RESULTS

The study enrolled 193 patients (mean age: 48.9 ± 18.7, 44.7% males), of whom 18.1% were familial cases. The mean follow-up period was 10.1 ± 9.4 years (8.5 ± 8.1 in sporadic and 16.9 ± 11.6 in familial MTC). Disease persistence 1-year after diagnosis and at last follow-up was detected in 56.1 and 60.4% patients, respectively. All-cause and DRM were 28.5 and 12.6%, respectively. Extra-thyroidal extension (ETE) and distant metastases (DM) were associated with disease persistence at last follow-up. ETE and DM were also significantly associated with DRM. Complete remission 1 year after diagnosis had high correlation with no evidence of disease at last follow-up (Cramer's V measure of association 0.884, P < 0.001) and with 100% disease-specific survival (Cramer's V measure of association 0.38, P < 0.001).

CONCLUSIONS

Apart from clinico-pathologic parameters, close correlation was found between 1-year status and long-term prognosis. These results underscore the importance of combining classical and dynamic factors for both sporadic and familial MTC prognostication and treatment decision making.

The application value of modified thyroid imaging report and data system in diagnosing medullary thyroid carcinoma

Medullary thyroid carcinoma (MTC) is highly malignant and quite different from the most common papillary thyroid carcinoma (PTC). However, most of the ultrasonic evaluation systems mainly aim at PTC at present. This study aims to evaluate the applicability of modified TI-RADS in diagnosing MTC and compare the sonographic differences of MTC, PTC, and benign nodules. Three thousand two hundred and forty-two thyroid nodules images confirmed by pathology were categorized according to modified TI-RADS and ACR TI-RADS classification. The performances of two TI-RADS were assessed by ROC curves. The correlations between classifications with the pathology and the consistency of different doctors were evaluated. The ultrasonic differences of MTC, PTC, and benign nodules were analyzed. As a result, the number of high suspicious US features increased, the malignant risk of nodules also increased of two classifications, with significant differences between categories (P < 0.001). Spearman correlation coefficients were 0.751 (modified TI-TADS) and 0.744 (ACR TI-RADS). Areas under the ROC curve of the modified TI-RADS and ACR TI-RADS were 0.960 and 0.872 (P < 0.001). At Best cut off points, the diagnostic value of modified TI-RADS was higher than that of ACR TI-RADS with a higher specificity, PPV, accuracy, and Youden index). By using modified TI-RADS to diagnose MTC and PTC, the sensitivity, specificity, NPV, accuracy, and Youden index were higher in MTC than PTC. The Kendall's correlation coefficients were 0.962, 0.930, and 0.987. MTC had special ultrasonography characters compared with PTC and benign nodules. These results suggest that modified TI-RADS is better than ACR TI-RADS in diagnosing thyroid carcinomas. Diagnostic value to MTC of modified TI-RADS is slightly higher than that to PTC, and the categorical results of different doctors were consistent. MTC had several particular features contrast to PTC and benign nodules.

Different outcomes in sporadic versus familial medullary thyroid cancer

BACKGROUND

Medullary thyroid carcinoma (MTC) has varying clinical course with familial cases (fMTC) diagnosed earlier than sporadic MTC (spMTC).

METHODS

A total of 273 MTCs (familial: n = 110 [40.3%], males: 38.5%) were followed for 1-35 years (median 5.0 years). Fifty one of the familial cases were operated because of positive findings at genetic screening. Disease extent at diagnosis and follow-up was recorded.

RESULTS

Mean age at diagnosis was: fMTC = 33.85 ± 16.5 years (range 4-74) and spMTC = 52.6 ± 14.0 years (range 16-81, P < .001). This difference remained when genetic screening cases were excluded. fMTCs had more frequently multifocality, smaller size, and more favorable stage at diagnosis (stages I and II: 60.9% vs 47.9%, stage III: 30.0% vs 23.9%, stage IV: 9.1% vs 28.9%, P = .01). fMTC had lower preoperative and postoperative calcitonin, more frequently remission (59.1% vs 47.2%) and less frequently progressive disease (8.2% vs 35.0%, P < .001). After excluding genetic screening cases, no difference in stage at diagnosis was observed. Outcome was more favorable in fMTC compared to sporadic (P = .002); the 10-year probability of lack of progression of disease differed significantly between fMTCs and spMTCs (86.4% vs 65.0%, P < .001).

CONCLUSION

After excluding genetic screening cases, although stage at diagnosis is similar, disease outcome remains worse in sporadic compared to fMTCs.

Ultrasound-guided laser ablation for local control of neck recurrences of medullary thyroid cancer. A feasibility study

BACKGROUND

Surgery is the standard treatment for cervical metastases of medullary thyroid cancer (MTC) diagnosed after initial surgical treatment. Repeated neck dissections, however, carry an elevated risk of complications, have an adverse impact on the quality of life, and sometimes do not achieve cure of the disease Clinical case: In a patient who had undergone two cervical neck dissections complicated by accessory nerve injury, an US-guided laser ablation (LA) of a lymph node metastasis of MTC was performed. LA was performed with two treatments during a five month period. The procedure was carried out with one optical fiber and an energy delivery of 3300 and 360 Joules. Treatments were well tolerated and resulted in complete structural and biochemical cure during a 12 month follow-up. No major complication was registered.

CONCLUSIONS

LA is a promising tool for the management of relapsing cervical metastases that are localized in non- critical areas and are characterized by low progression rate. Advantages of LA are the outpatient setting, the absence of general anesthesia, the tolerability and the safety of the procedure. Thus, LA may be considered as an alternative approach to surgery or active surveillance for the management of local recurrences of MTC in selected patients.

Ultrasonographic characteristics of medullary thyroid carcinoma: a comparison with papillary thyroid carcinoma

This study was designed to explore differences in the ultrasonographic characteristics of medullary thyroid carcinoma (MTC) and papillary thyroid carcinoma (PTC). This study included 35 cases of MTC and 96 cases of PTC that were surgically and pathologically confirmed. Preoperative ultrasound images were retrospectively reviewed by two physicians (with 5 years’ experience in thyroid ultrasound) under the premise of unknown pathological results. Various ultrasonic features of nodules were assessed objectively. The clinical features of components were determined by other physicians. Age, sex, unilateral or bilateral involvement of thyroid gland, lesion size, margin, shape, echogenicity, calcification, intranodular blood flow, cervical lymph node, and tumor node metastasis (TNM) stage were compared between MTC and PTC groups. Age, sex, involvement of the thyroid gland, margin, and calcification were similar for the MTC and PTC groups. Compared with the PTC group, the lesion size in the MTC group was significantly larger (P < 0.001). A taller-than-wide shape (aspect ratio > 1) was significantly less likely in the MTC group than the PTC group (P < 0.001). A mixed echogenicity was significantly more common in the MTC group than the PTC group (P = 0.003). The MTC group had significantly enhanced intranodular blood flow (P < 0.001). The TNM stage of the MTC group was significantly higher than that of PTC group (P = 0.001). Medullary thyroid carcinomas differ significantly from PTCs in lesion size, shape, echogenicity, and intranodular blood flow.

Clinical and pathological analysis of 19 cases of medullary thyroid carcinoma without an increase in calcitonin

BACKGROUND

Medullary thyroid carcinoma (MTC), defined as a malignant tumour with C-cell differentiation, is of neuroendocrine origin and is characterized by the synthesis and secretion of calcitonin (CT). MTC without CT secretion has been reported on rare occasions. The purpose of this study was to evaluate the histological, immunohistochemical, and molecular pathologic features as well as the clinical significance of non-secretory MTC (NCR-MTC).

METHODS

A retrospective analysis of patients with NCR-MTC was performed. The clinical features of NCR-MTC, including age, gender, tumour size and number, clinical signs of hypocalcaemia and diarrhoea, and the presence of lymph node metastasis, as well as the pathologic features of the disease, including tumour morphology, presence of neuroendocrine structures, capsular invasion, and immunohistochemical expression and presence of mutations in the RET gene, were evaluated.

RESULTS

Nineteen patients with NCR-MTC were identified among 158 patients with MTC, resulting in a prevalence rate of 12.02%. Patients with NCR-MTC typically had masses less than 1cm in size (73.7%, 14/19). Hypocalcaemia was not present in 94.7% (18/19) of patients. While 42.1% (8/19) of patients with NCR-MTC did not have amyloid deposits, only 18% (25/139) of patients with secretory MTC did not have such deposits. While 95.7% (133/139) of the control group of patients with secretory MTC had neuroendocrine tumour structure, only 84.2% (16/19) of the patients with NCR-MTC had this type of tumour structure. Patients with NCR-MTC were also less likely to have vascular tumour thrombus, lymph node metastasis or thyroid capsular invasion. With regard to immunohistochemistry, CT expression was mostly negative, and carcinoembryonic antigen (CEA) expression was positive in 21.1% (4/19) of patients with NCR-MTC, while only 5.8% (8/139) of patients in the control group had positive CEA expression.

CONCLUSIONS

The prevalence of NCR-MTC was low (12.02%). This type of tumour was smaller in size and more differentiated. Compared with the control group, relatively few patients had obvious symptoms, hypocalcaemia, lymph node metastasis, thyroid capsular or vascular invasion, or tumours with amyloid or neuroendocrine tumour structure.

Systemic treatment and management approaches for medullary thyroid cancer

Although rare, medullary thyroid cancer (MTC) exemplifies the value that ever-expanding knowledge of molecular pathways and mechanisms brings to managing challenging cancers. Although surgery can be curative for MTC in many patients, a substantial proportion of patients present with locoregional or distant metastatic disease. Once distant disease occurs, treatment options are limited, and conventional cancer treatments such as cytotoxic chemotherapy are of minimal benefit. Biomarkers such as calcitonin and carcinoembryonic antigen are important correlates of disease burden as well as predictors of disease progress, including recurrence and survival. MTC is either sporadic (∼75%) or inherited (∼25%) as an autosomal dominant disease. Regardless, germline and somatic mutations, particularly in the rearranged during transfection (RET) proto-oncogene, are key factors in the neoplastic process. Gain-of-function RET mutations result in overactive proteins that lead to abnormal activation of downstream signal transduction pathways, resulting in ligand-independent growth and resistance to apoptotic stimuli. Specific RET mutation variants have been found to correlate with phenotype and natural history of MTC with some defects portending a more aggressive clinical course. Greater understanding of the consequence of the aberrant signaling pathway has fostered the development of targeted therapies. Two small-molecule tyrosine kinase inhibitors, vandetanib and cabozantinib, are currently available as approved agents for the treatment of advanced or progressive MTC and provide significant increases in progression-free survival. Since there have been no head-to-head comparisons, clinicians often select between these agents on the basis of familiarity, patient characteristics, comorbidities, and toxicity profile.

Medullary thyroid carcinoma: a review on ethical considerations in treatment of children

Thyroid carcinoma is the most common malignancy of the endocrine system and it accounts approximately 1%-3% of all human cancers. Among the three subtypes of thyroid cancers, medullary thyroid carcinoma (MTC) is the most common cause of death in patients with multiple endocrine neoplasia (MEN) type 2A (MEN2A), MEN type 2B (MEN2B) and familial medullary thyroid carcinoma (FMTC). Generally, MTC accounts for up to 10% of all types of thyroid cancers. It is one of the aggressive forms of thyroid carcinoma which is manifested in childhood ages more than adults, and it comprises about 17% of all pediatric thyroid cancer. Like the other cancers, prevention of MTC is easier than its cure. In the recent decades (from 1993) the diagnosis of asymptomatic child carrying RET mutations in the affected families by MTC, has been provided by genetic screening, and prophylactic thyroidectomy is an efficacy therapeutic procedure. On the one hand, according to near the complete penetrance of the disease and its onset in the early years of life, it is required to accelerate the protection of at-risk children with relative affected by MTC and on the other hand, there are several obstructions to MTC treatment including: 1) the proband's refusal to disclose the RET mutation genetic testing results, 2) children's vulnerability because of their inability to participate in the informed consent, and 3) the existence of conflict between physicians and children's guardian. In this review article, the recommendations and ethical issues of MTC treatment in asymptomatic and at-risk children have been summarized.

[A Case of Hereditary Medullary Thyroid Cancer (MEN2A/FMTC) Diagnosed at the Time of Recurrence]

We report a 42-year-old man with hereditary medullary thyroid cancer (multiple endocrine neoplasia, MEN2A/familial medullary thyroid carcinoma, FMTC), which was diagnosed at the time of tumor recurrence. He had a past history of a left thyroidectomy with neck dissection 7 years previously. A RET gene analysis revealed a point mutation (codon 618), and we diagnosed him as having hereditary medullary thyroid cancer. We resected the recurrent tumor in the right thyroid lobe together with performing a right lateral and central neck dissection. A RET gene analysis should be performed for patients with medullary thyroid cancer. When a RET gene mutation is present, a total thyroidectomy must be performed for the medullary thyroid cancer.

Treatment compliance and severe adverse events limit the use of tyrosine kinase inhibitors in refractory thyroid cancer

Objective

The aim of the present study was to assess patient compliance with tyrosine kinase inhibitor (TKI) treatment used for refractory and progressive thyroid cancer, in addition to the efficacy and serious adverse events associated with these agents.

Methods

We retrospectively analyzed data from adult patients with metastatic differentiated or medullary thyroid cancer unresponsive to conventional treatment and treated with TKIs. Patients received treatment until disease progression or onset of serious adverse events, or until they expressed an intention to stop treatment.

Results

Twenty-four patients received TKIs. The median duration of treatment was four (range: 1–19) cycles. The most frequent adverse events were fatigue, nausea, diarrhea, hypertension, and stomatitis, and the most severe were nasal bleeding, diarrhea, heart failure, rhabdomyolysis, renal failure, QT prolongation, neutropenia, and severe fatigue. Dose reduction was required in eight patients, while five decided to terminate TKI therapy because adverse events impaired their everyday activities. During therapy, two patients showed a partial response and three showed stable disease. The lungs were the metastatic sites favoring a response to treatment.

Conclusion

Patient selection and meticulous pretreatment education are necessary in order to ensure adherence with TKI therapy. If adverse events appear, dose reduction or temporary treatment interruption may be offered because some adverse events resolve with continuation of treatment. In the event of serious adverse events, treatment discontinuation is necessary.

Neuroendocrine tumors: beyond the abdomen

Several classification systems for neuroendocrine tumors (NETs) exist, which use variable terminology and criteria for grading and staging. This variability in terminology can cause confusion and difficulty in recognizing which tumors are, in fact, members of this heterogeneous group of malignancies. The largest group of NETs, the gastroenteropancreatic NETs, has been well described and characterized; however, there are less-recognized extra-abdominal NETs that can arise from nearly any organ in the body. In this article, the clinical features and imaging appearances of the extra-abdominal NETs will be reviewed, compared, and contrasted. This diverse group consists of paragangliomas, Merkel cell carcinomas, esthesioneuroblastomas, NETs of the lung, and medullary thyroid carcinomas. Recognition of these tumors as part of the larger group of NETs is important for understanding how best to approach imaging for their diagnosis, staging, and potential treatment. Familiarity with the computed tomographic and magnetic resonance imaging appearances and the role of radionuclide imaging of these heterogeneous groups aids in the correct diagnosis and in treatment planning.

Update on medullary thyroid cancer

Medullary thyroid carcinoma (MTC) is a rare type of thyroid cancer, demonstrating variable behavior from indolent disease to highly aggressive, progressive disease. There are distinguishing phenotypic features of sporadic and hereditary MTC. Activation or overexpression of cell surface receptors and up-regulation of intracellular signaling pathways in hereditary and sporadic MTC are involved in the disease pathogenesis. There has been an exponential rise in clinical trials with investigational agents, leading to approval of 2 medications for progressive, advanced MTC. Developments in understanding the pathogenesis of MTC will hopefully lead to more effective and less toxic treatments of this rare but difficult to treat cancer.

Quantitative assessment of the association between L769L and S836S polymorphisms at RET gene and medullary thyroid carcinoma risk

RET single nucleotide polymorphisms (SNPs) have been implicated in the pathogenesis and progression of medullary thyroid carcinoma (MTC). Epidemiologic studies have evaluated the association between RET L769L and S836S polymorphisms and predisposition to MTC. However, the results were inconclusive. A literature search was performed using the PubMed database for relevant studies published through October 31, 2013. A total of 13 eligible studies were selected for this meta-analysis, including 1,117 cases and 1,916 controls for L769L and 1,230 cases and 2,246 controls for S836S. The carrier frequency of the variant alleles was 26.3 % in patients with MTC and 24.6 % in controls for L769L polymorphism, and 6.6 % in patients with MTC and 5.0 % in controls for S836S polymorphism. In our pooled analysis of all these studies, the results of our meta-analysis suggested that the RET L769L variant was not significantly associated with an elevated MTC risk (odds ratio (OR) 1.06, 95 % confidence interval (CI) 0.94-1.19). And there was no evidence for the association between the S836S variant and MTC risk (OR 1.20, 95 % CI 0.97-1.49). Moreover, no significant differences were found when considering patients or controls heterozygous or homozygous for RET L769L and S836S polymorphisms. In conclusion, this meta-analysis suggests that RET L769L and S836S polymorphisms may not be associated with MTC development.

Radioactive iodine in the treatment of medullary thyroid carcinoma: a controlled multicenter study

OBJECTIVE

Radioactive iodine (RAI) therapy in medullary thyroid carcinoma (MTC) is applied in some centers, based on the assumption that cross-irradiation from thyroid follicular cells may be beneficial. However, no systematic studies on the effect of RAI treatment in MTC have been performed. The aim of this study was to analyze the effect of RAI treatment on survival in MTC patients.

DESIGN

Retrospective multicenter study in eight University Medical Centers in The Netherlands.

METHODS

Two hundred and ninety three MTC patients without distant metastases who had undergone a total thyroidectomy were included between 1980 and 2007. Patients were stratified by clinical appearance, hereditary stage, screening status, and localization. All patients underwent regular surgical treatment with additional RAI treatment in 61 patients. Main outcome measures were disease-free survival (DFS) and disease-specific survival (DSS). Cure was defined as biochemical and radiological absence of disease.

RESULTS

In multivariate analysis, stratification according to clinical appearance (P=0.72), hereditary stage (P=0.96), localization (P=0.69), and screening status (P=0.31) revealed no significant effects of RAI treatment on DFS. Multivariate analysis showed no significant difference in DSS for the two groups stratified according to clinical appearance (P=0.14). Owing to limited number of events, multivariate analysis was not possible for DSS in the other groups of stratification.

CONCLUSIONS

Based on the results of the present analysis, we conclude that RAI has no place in the treatment of MTC.

[Surgical therapy for thyroid gland malignancies]

Surgical therapy for thyroid neoplasms is based on tumor histology and comprises stage-adapted procedures with a high degree of inter-individual variability. This can range from waiting and monitoring, to extensive multivisceral surgery. Grouping together histologically different types of malignancies leads to false assumptions when gauging the radicality of surgery necessary in each particular case. Surgical therapy requires not only an understanding of the biological behavior of the tumor and the risk that it or the therapy poses to the patient, but also knowledge of a wide surgical spectrum of limited and complex resection procedures in the neck and thorax region. The following recommendations are based primarily on the guidelines of the Surgical Working Group for Endocrinology of the German Society for General and Visceral Surgery as well as on the authors' own experience and, where indicated, the guidelines of other working groups.

Medullary thyroid carcinoma: the influence of policy changing in clinical characteristics and disease progression

OBJECTIVE

Medullary thyroid carcinoma (MTC) has varying clinical course. We assessed trends in MTC presentation during the last 34 years.

DESIGN

Retrospective study.

METHODS

One hundred and fifty one patients (44.4% males) were followed for 0.934 years. Patients were classified according to year of diagnosis: group 1, 1977-2000 (n=53) and group 2, 2001-2011 (n=98). Extent of disease at diagnosis, during follow-up, number of surgeries, and pre- and postoperative calcitonin levels were recorded.

RESULTS

In total, 48.34% reported family history of MTC. Group 1 had larger tumors (median 1.70 (intraquartile range (IQR) 1.7) vs 1.1 (1.2) cm, P=0.045, Mann-Whitney), they presented less frequently micro-MTCs (27.8 vs 46.1%, P=0.045), and underwent more multiple surgeries (63.3 vs 20.0%, P<0.001). Group 1 had more frequently progressive disease (35.8 vs 12.2%, P=0.003) and distant metastasis at follow-up (39.7 vs 17.4%, P=0.017). Chronological group (HR 0.15, 95% CI 0.03-0.68, P=0.015) and distant metastases at follow-up (HR 0.07, 95% CI 0.015-0.30, P=0.001) were independently associated with 10-year disease progression (P<0.001). In sporadic cases, cervical lymph node invasion and distant metastases at diagnosis were more frequent in group 1 (72.7 vs 45.5%, P=0.032 and 27.3 vs 5%, P=0.019 respectively); disease stage at diagnosis was more advanced (P=0.004). They underwent more multiple surgeries (P<0.001), presented more frequently distant metastasis at follow-up (67.7 vs 20.0%, P=0.002), had less frequently remission, and more frequently progressive disease (21.4 vs 58.0% and 64.3 vs 14.0% respectively, P<0.001). Postoperative calcitonin levels were higher (P=0.024).

CONCLUSIONS

Recently, an increase in micro-MTCs is observed, while indices of invasiveness and persistence of disease are better. Increased awareness in familial cases, routine calcitonin measurements, and improved surgical procedures could be responsible.