Temporal Trends in the Presentation, Treatment, and Outcome of Medullary Thyroid Carcinoma: An Israeli Multicenter Study

New strategy for intraoperative phonosurgical management of recurrent laryngeal nerve infiltrated by thyroid carcinoma

PURPOSE

Treating an infiltration of the recurrent laryngeal nerve (RLN) by thyroid carcinoma remains a subject of ongoing debate. Therefore, this study aims to provide a novel strategy for intraoperative phenosurgical management of RLN infiltrated by thyroid carcinoma.

METHODS

Forty-two patients with thyroid carcinoma infiltrating the RLN were recruited for this study and divided into three groups. Group A comprised six individuals with medullary thyroid cancer who underwent RLN resection and arytenoid adduction. Group B consisted of 29 differentiated thyroid cancer (DTC)patients who underwent RLN resection and ansa cervicalis (ACN)-to-RLN anastomosis. Group C included seven patients whose RLN was preserved.

RESULTS

The videostroboscopic analysis and voice assessment collectively indicated substantial improvements in voice quality for patients in Groups A and B one year post-surgery. Additionally, the shaving technique maintained a normal or near-normal voice in Group C one year post-surgery.

CONCLUSION

The new intraoperative phonosurgical strategy is as follows: Resection of the affected RLN and arytenoid adduction is required in cases of medullary or anaplastic carcinoma, regardless of preoperative RLN function. Suppose RLN is found infiltrated by well-differentiated thyroid cancer (WDTC) during surgery, and the RLN is preoperatively paralyzed, we recommend performing resection the involved RLN and ACN-to-RLN anastomosis immediately during surgery. If vocal folds exhibit normal mobility preoperatively, the MACIS scoring system is used to assess patient risk stratification. When the MACIS score > 6.99, resection of the involved RLN and immediate ACN-to-RLN anastomosis were performed. RLN preservation was limited to patients with MACIS scores ≤ 6.99.

Overview of Thyroid and Parathyroid Disease-The Endocrinology Perspective

Thyroid and parathyroid disorders are quite common in the population and range from benign to malignant conditions that may be hormonally active or inactive. Select disorders of the thyroid and parathyroid can be managed medically, although there are a variety of circumstances that may require definitive management with surgery. Surgical intervention may be required for hormonal control, compressive symptoms, or for the removal and/or control of malignancy. The endocrinologist's perspective of the preoperative and postoperative management regarding thyroid and parathyroid surgeries will be discussed.

Clinical characteristics of a large familial cohort with Medullary thyroid cancer and germline Cys618Arg RET mutation in an Israeli multicenter study

Objective

To determine genealogical, clinical and pathological characteristics of a cohort with Cys618Arg mutation from an Israeli multicenter MTC study.

Methods

Retrospective database analysis examining RET mutations and comparing Cys618Arg and Cys634Arg/Thr/Tyr subgroups.

Results

Genetic testing was performed in 131/275 MTC patients (47.6%). RET mutations were found in 50/131 (38.2%), including Cys618Arg (28/50 cases,56%), and Cys634Arg/Thr/Tyr (15/50,30%). Through genealogical study, 31 MTC patients were found descendants of one family of Jewish Moroccan descent, accounting for 27/28 patients with documented Cys618Arg mutation and 4 patients without available genetic testing. Familial Cys618Arg cases (n=31) and Cys634Arg/Thr/Tyr cases (n=15, from 6 families) were compared. Although surgical age was similar (25.7 vs 31.3 years, p=0.19), the Cys618Arg group had smaller tumors (8.9mm vs 18.5mm, p=0.004) and lower calcitonin levels (33.9 vs 84.5 X/ULN, p=0.03). Youngest ages at MTC diagnosis were 8 and 3 years in Cys618Arg and Cys634Arg/Thr/Tyr cohorts, respectively. Long-term outcome was similar between groups. The Cys618Arg cohort had lower rates of pheochromocytoma (6.5% vs 53.3%, p=0.001) and primary hyperparathyroidism (3.2% vs 33.3%, p=0.01).

Conclusion

This is the first description of RET mutation distribution in Israel. Of 131 tested MTC patients, Cys618Arg was the predominant mutation. To the best of our knowledge, this is the largest cohort of Cys618Arg mutation described. For Cys618Arg and Cys634Arg/Thr/Tyr cohorts, MTC was diagnosed earlier than expected, likely due to familial genetic screening, and MTC outcomes were similar between groups. International studies are necessary to further characterize the clinical features of Cys618 mutations due to their relative rarity.

A Comparison of Outcomes in Medullary Thyroid Carcinoma Patients With and Without a Preoperative Diagnosis: A Multicenter Retrospective Cohort Study

Background: Cytological limitations pose a challenge to preoperative diagnosis of medullary thyroid carcinoma (MTC) and therefore, a significant subset of patients is only diagnosed postoperatively. The objective of this study was to investigate the impact of knowledge of a preoperative MTC diagnosis on disease management and outcomes. Methods: Multicenter, retrospective, cohort study of MTC patients treated in Israel from January 2000 to June 2021. We compared cohorts of patients according to the presence or absence of a preoperative MTC diagnosis. Results: Ninety-four patients with histologically confirmed MTC were included (mean age 56.2 ± 14.3 years, 43% males). Fifty-three patients (56%) had a preoperative MTC diagnosis (preop-Dx group), and 41 (44%) were confirmed only postoperatively (no-Dx group). The extent of surgical resection, including completion procedures, was as follows: total thyroidectomy in 83% versus 100% (p = 0.002), central lymph node dissection (LND) in 46% versus 98% (p < 0.001), ipsilateral lateral LND in 36% versus 79% (p < 0.001), and contralateral lateral LND in 17% versus 28% (NS), in the no-Dx versus the preop-Dx group, respectively. Pathology confirmed a smaller median tumor size of 16 ± 17.4 mm versus 23 ± 14.0 mm (p = 0.09), a higher proportion of micro-MTC (size ≤10 mm) 32% versus 15% (p = 0.03), and a higher rate of co-occurrence of follicular cell-derived carcinoma 24% versus 4% (p = 0.003), in the no-Dx compared to the preop-Dx group, respectively. The rates of extrathyroidal and extranodal tumor extension were not significantly different between the groups. At the last follow-up, the biochemical cure was attained in 55% [CI 0.38-0.71] compared to 64% [CI 0.50-0.77] of the no-Dx and the preop-Dx group, respectively (p = 0.41). After the exclusion of patients with micro-MTC, biochemical cure was more commonly achieved in the preop-Dx group (33% [CI 0.14-0.52] vs. 62% [CI 0.46-0.77], p = 0.04). Preop-Dx patients had improved overall survival compared to the no-Dx group (log-rank p = 0.04) over a median follow-up of 82 months (interquartile range [IQR] 30-153). Conclusions: Preoperatively, the diagnosis of MTC is often missed. An accurate preoperative diagnosis of MTC may enable guideline-concordant surgical treatment and ultimately contribute to an overall survival benefit in MTC patients.

Surgical selection and prognostic analysis in patients with unilateral sporadic medullary thyroid carcinoma

PURPOSE

The extent of thyroid surgery and cervical lymph node dissection of unilateral sporadic medullary thyroid carcinoma (sMTC) is still controversial, and the aim of this study was to investigate whether hemithyroidectomy was adequate as a locally curative surgery for patients with unilateral sMTC.

METHODS

This study is a retrospective case series of patients with sMTC who underwent curative total thyroidectomy or hemithyroidectomy in our institution from January 2011 to December 2019.

RESULTS

In total, 129 patients who met the inclusion criteria were enrolled including 49 (38.0%) patients who underwent total thyroidectomy and 80 (62.0%) patients who underwent hemithyroidectomy. About 80 (62.0%) patients achieved a biochemical cure (BC), whereas there was no significant difference between two groups in biochemical cure rate (61.2% versus 62.5%, P = 0.885). A logistic regression analysis showed a strong negative correlation between the factors of preoperative calcitonin level and pTNM stage and biochemical cure. In the log-rank test, no significant difference in OS (P = 0.314) and DFS (P = 0.409) was found between the two surgical groups. Lateral cervical lymph node metastasis and pTNM stage were significant prognostic factors affecting DFS in univariate analysis; moreover, absence of biochemical cure, tumor size ≥ 4 cm and lateral cervical lymph node metastasis were independent risk factors of unilateral sMTC patients in our analysis.

CONCLUSION

For patients with unilateral sMTC, hemithyroidectomy was adequate as a locally curative surgery, because the patients underwent total thyroidectomy did not benefit more from it in the aspects of BC/OS/RFS, while the postoperative increasing incidence rate of postoperative hypocalcemia could not improve patients' quality of life.

Identifying Thyroid Carcinoma-Related Genes by Integrating GWAS and eQTL Data

Thyroid carcinoma (TC) is the most common endocrine malignancy. The incidence rate of thyroid cancer has increased rapidly in recent years. The occurrence and development of thyroid cancers are highly related to the massive genetic and epigenetic changes. Therefore, it is essential to explore the mechanism of thyroid cancer pathogenesis. Genome-Wide Association Studies (GWAS) have been widely used in various diseases. Researchers have found multiple single nucleotide polymorphisms (SNPs) are significantly related to TC. However, the biological mechanism of these SNPs is still unknown. In this paper, we used one GWAS dataset and two eQTL datasets, and integrated GWAS with expression quantitative trait loci (eQTL) in both thyroid and blood to explore the mechanism of mutations and causal genes of thyroid cancer. Finally, we found rs1912998 regulates the expression of IGFALS (P = 1.70E-06) and HAGH (P = 5.08E-07) in thyroid, which is significantly related to thyroid cancer. In addition, KEGG shows that these genes participate in multiple thyroid cancer-related pathways.

Trends in the Diagnosis and Treatment of Patients with Medullary Thyroid Carcinoma in Korea

BACKGROUND

Thyroid cancer is becoming increasingly common worldwide, but little is known about the epidemiology of medullary thyroid carcinoma (MTC). This study investigated the current status of the incidence and treatment of MTC using Korean National Health Insurance Service (NHIS) data for the entire Korean population from 2004 to 2016.

METHODS

This study included 1,790 MTC patients identified from the NHIS database.

RESULTS

The age-standardized incidence rate showed a slightly decreasing or stationary trend during the period, from 0.25 per 100,000 persons in 2004 to 0.19 in 2016. The average proportion of MTC among all thyroid cancers was 0.5%. For initial surgical treatment, 65.4% of patients underwent total thyroidectomy. After surgery, external-beam radiation therapy (EBRT) was performed in 10% of patients, a proportion that increased from 6.7% in 2004 to 11.0% in 2016. Reoperations were performed in 2.7% of patients (n=49) at a median of 1.9 years of follow-up (interquartile range, 1.2 to 3.4). Since November 2015, 25 (1.4%) patients with MTC were prescribed vandetanib by December 2016.

CONCLUSION

The incidence of MTC decreased slightly with time, and the proportion of patients who underwent total thyroidectomy was about 65%. EBRT, reoperation, and tyrosine kinase inhibitor therapy are additional treatments after initial surgery for advanced MTC in Korea.

External Beam Radiotherapy for Medullary Thyroid Cancer Following Total or Near-Total Thyroidectomy

OBJECTIVES

Medullary thyroid carcinoma (MTC) often presents with advanced disease and takes an aggressive course as compared with more well-differentiated thyroid cancers. The role of adjuvant therapy, specifically external beam radiotherapy (EBRT), remains disputed. This study investigated the impact of EBRT on survival in MTC.

STUDY DESIGN

Cross-sectional analysis of a national database.

SETTING

Patients with MTC were identified from the SEER program (Surveillance, Epidemiology, and End Results).

METHODS

Collected variables included age, sex, race, T and N stages, lymph node yield, and use of EBRT. Propensity score matching was performed to determine the association of EBRT with overall and disease-specific survival.

RESULTS

A total of 2046 patients with locoregional MTC were identified. Of these, 152 received EBRT. Patients receiving EBRT were older and had more advanced disease. EBRT was not associated with differences in overall survival (hazard ratio, 1.12; 95% CI, 0.76-1.65) or disease-specific survival (1.66; 0.93-2.95), as well as in subset analysis of age and disease extent. Long-term overall survival was similar, with 77.3% (95% CI, 70.1%-85.3%) and 58.3% (48.2%-70.5%) of patients without EBRT alive at 5 and 10 years, respectively (vs 70.7% [63.2%-79.1%] and 52.3% [43.3%-63.2%] of patients with EBRT). There were no differences in 5- and 10-year disease-specific survival.

CONCLUSION

EBRT was not associated with improved overall or disease-specific survival in patients with MTC. Decisions regarding EBRT must be made with consideration of morbidity relative to benefit for individual patients.

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.

Trends in Diagnostics, Surgical Treatment, and Prognostic Factors for Outcomes in Medullary Thyroid Carcinoma in Norway: A Nationwide Population-Based Study

BACKGROUND

Medullary thyroid carcinoma (MTC) is rare. Nationwide population-based studies are important to evaluate its clinical course.

OBJECTIVES

To describe all patients with MTC in Norway during 1994-2016 and compare time-related trends in diagnostics and surgical treatment, including prognostic factors for biochemical cure and disease-specific survival (DSS).

METHODS

This retrospective population-based cohort study includes data for 228 out of 237 patients (96%) with MTC; 201 patients were surgically treated. Patients were identified in the 4 regional centers treating MTC and by the Cancer Registry of Norway. Data were collected from patients' files. Trends were compared over 2 study periods.

RESULTS

MTC accounted for 4.2% of thyroid carcinomas. During the study periods, the incidence increased from 0.18 to 0.25: 100,000 per year, preoperative diagnostics improved with increased use of calcitonin, ultrasound, and fine-needle cytology (p = 0.010, p < 0,001, and p = 0.001), patients were diagnosed at an earlier tumor stage (p = 0.004), and more patients were cured (p = 0.002). Via multivariate analysis of patients with metastatic lymph nodes, independent prognostic factors for cure were: a low ratio of metastatic and total number of dissected lymph nodes (p = 0.021) and no extrathyroidal extension (p = 0.030). Independent prognostic factors for DSS were: no distant metastasis, a younger age, and a low ratio of metastatic and dissected lymph nodes (p = 0.005, p = 0.020, p = 0.022).

CONCLUSIONS

Preoperative diagnostics have improved over time with increased therapeutic control. A low ratio of metastatic and dissected lymph nodes predicts better outcomes in patients with metastatic lymph nodes.

Clinical Validation of the Prognostic Stage Groups of the Eighth-Edition TNM Staging for Medullary Thyroid Carcinoma

CONTEXT

Despite advances in thyroid cancer staging systems, considerable controversy about the current staging system for medullary thyroid carcinoma (MTC) continues.

OBJECTIVE

We aimed to evaluate the prognostic performance of the current eighth edition of the American Joint Committee on Cancer (AJCC)/Union for International Cancer Control TNM staging system (TNM-8) and the alternative proposed prognostic stage groups based on recursive partitioning analysis (TNM-RPA).

DESIGN, SETTING, AND PATIENTS

We retrospectively analyzed 182 patients with MTC treated at a single tertiary Korean hospital between 1995 and 2015.

INTERVENTIONS AND MAIN OUTCOME MEASURES

Survival analysis was conducted according to TNM-8 and TNM-RPA. The area under the receiver-operating characteristic curve (AUC), the proportion of variation explained (PVE), and the Harrell concordance index (C-index) were used to evaluate predictive performance.

RESULTS

Under TNM-8, only two (1.1%) patients were downstaged compared with the seventh edition of the AJCC TNM staging system (TNM-7). The AUC at 10 years, PVE, and C-index were 0.679, 8.7%, and 0.744 for TNM-7 and 0.681, 8.9%, and 0.747 for TNM-8, respectively. Under TNM-RPA, 104 (57.14%) patients were downstaged compared with TNM-8. TNM-RPA had better prognostic performance with respect to cancer-specific survival (AUC at 10 years, 0.750; PVE, 20.9%; C-index, 0.881).

CONCLUSIONS

The predictive performance of the revised TNM-8 in patients with MTC has not changed despite its modification from TNM-7. The proposed changes in TNM-RPA were statistically valid and may present a more reproducible system that better estimates cancer-specific survival of individual patients.