Completeness of RET testing in patients with medullary thyroid carcinoma in Denmark 1997-2013: a nationwide study

Biomarker testing in patients diagnosed with advanced/metastatic medullary thyroid cancer in the United States

Aim: To describe real-world testing patterns for RET in US patients with advanced/metastatic medullary thyroid cancer and determine consistency of real-world testing practices with national guidelines. Materials & methods: The authors performed a retrospective medical record analysis of patients with advanced/metastatic medullary thyroid cancer who initiated systemic therapy between 2013 and 2018. Seventy-five US-based oncologists collected the data using a customized electronic data collection form. Results: A total of 59.6% (121 of 203) of patients underwent testing for RET, and 37.2% (45 of 121) had a RET mutation, of which 55.6% were identified as RET mutation-positive before initial diagnosis. Overall, 90 (44.3%) patients were tested for biomarkers on or after initial diagnosis, with RET being the most tested (95.6%) biomarker. Conclusion: The authors' findings suggest an opportunity to improve testing rates in accordance with treatment guidelines.

Diagnostic characteristics, treatment patterns, and clinical outcomes for patients with advanced/metastatic medullary thyroid cancer

Background

Medullary thyroid cancer (MTC) accounts for approximately 1.6% of new cases of thyroid cancer. The objective of this study was to describe patient characteristics, biomarker testing, treatment patterns, and clinical outcomes among patients with advanced/metastatic MTC in a real-world setting in the United States and to identify potential gaps in the care of these patients.

Methods

Selected oncologists retrospectively reviewed medical records of patients aged ≥ 12 years diagnosed with advanced MTC. Patients must have initiated ≥ 1 line of systemic treatment for advanced/metastatic MTC between January 2013–December 2018 to be eligible. Patient characteristics, biomarker testing, and treatment patterns were summarized descriptively; progression-free survival (PFS) and overall survival (OS) were estimated using the Kaplan–Meier method.

Results

The 203 patients included in this study had a mean (SD) age of 52.2 (10.4) years; mean (SD) duration of follow-up from start of first-line treatment was 24.5 (16.0) months. Most patients (82.8%) were initially diagnosed with stage IVA, IVB, or IVC disease. Among all patients, 121 (59.6%) had testing for RET mutations, of whom 37.2% had RET-mutant MTC. The RET-mutation type was reported for 28 patients; the most common mutations reported were M918T (64.3%) and C634R (32.1%). Of the 203 patients, 75.9% received only one line of systemic treatment for advanced disease, and 36% were still undergoing first-line therapy at the time of data extraction. Cabozantinib (30.0%), vandetanib (30.0%), sorafenib (17.2%), and lenvatinib (4.9%) were the most common first-line treatments. Among 49 patients who received second-line treatment, most received cabozantinib (22.4%), vandetanib (20.4%), lenvatinib (12.2%), or sunitinib (12.2%). Median PFS (95% confidence interval [CI]) from start of first- and second-line treatments was 26.6 months (20.8–60.8) and 15.3 months (6.6-not estimable [NE]), respectively. Median OS from initiation of first- and second-line treatment was 63.8 months (46.3-NE) and 22.4 months (12.4-NE), respectively.

Conclusions

For the treatment of advanced/metastatic MTC, no specific preference of sequencing systemic agents was observed in the first- and second-line settings. Considering the recent approval of selective RET inhibitors for patients with RET-mutant MTC, future research should investigate how treatment patterns evolve for these patients.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13044-021-00119-9.

Hereditary Medullary Thyroid Carcinoma: Genotype, Phenotype and Outcomes in a North Indian Cohort

BACKGROUND

Aggressiveness of hereditary medullary thyroid carcinoma (hMTC) has been conventionally described to correlate with American Thyroid Association (ATA) risk groups based on RET mutations. Recent evidence increasingly contradicts this notion. We studied the RET genotype and its correlation with disease phenotype and survival outcomes in a cohort of hMTC patients.

METHODS

In a retrospective cohort of 55 hMTC patients from 23 families treated at a north Indian tertiary care institute over 15-years, RET genotype was correlated with disease phenotype (clinical, biochemical, and pathological attributes) and outcomes in terms of biochemical cure (normalization of serum calcitonin), structural cure, overall survival (OS) and disease specific survival (DSS).

RESULTS

Forty-nine patients had Multiple Endocrine Neoplasia (MEN)-type 2A syndrome, 02 had MEN-2B, and 4 had familial MTC. Two patients belonged to highest ATA risk, 41 to high-risk, and 12 to moderate risk categories. Age of the patients or stage of disease at presentation did not differ significantly between the ATA risk groups. Though the baseline serum calcitonin was significantly higher in highest risk category, the biochemical cure rates were not significantly different. At a median follow up of 48 months (Inter-quartile range 18-84, range 12-192) structural cure rates in ATA moderate and high risk groups were significantly higher than highest risk group (p = 0.04). No significant difference in OS between the three ATA groups of hMTC among the patients who underwent surgical treatment was observed (p = 0.098).

CONCLUSIONS

The ATA moderate and high risk groups have better structural cure rates compared to ATA highest risk group. The biochemical cure and overall survival rates did not significantly differ between ATA risk-groups, and were impacted by the disease stage at presentation. The current ATA risk-groups do not reliably predict the outcomes in terms of biochemical cure and survival in hMTC patients.

The synergy of germline C634Y and V292M RET mutations in a northern Chinese family with multiple endocrine neoplasia type 2A

Genetic analysis for germline mutations of RET proto-oncogene has provided a basis for individual management of medullary thyroid carcinoma (MTC) and pheochromocytoma. Most of compound mutations have more aggressive phenotypes than single point mutations, but the compound C634Y/V292M variant in MTC has never been reported. Thus, we retrospectively investigated synergistic effect of C634Y and V292M RET germline mutations in family members with multiple endocrine neoplasia type 2A. Nine of 14 family members in a northern Chinese family underwent RET mutation screening using next-generation sequencing and PCR followed by direct bidirectional DNA sequencing. Clinical features of nine individuals were retrospectively carefully reviewed. In vitro, the scratch-wound assay was used to investigate the difference between the cells carrying different mutations. We find no patients died of MTC. All 3 carriers of the V292M variant were asymptomatic and did not have biochemical or structural evidence of disease (age: 82, 62 and 58). Among 4 C634Y mutation carriers, 2 patients had elevated calcitonin with the highest (156 pg/mL) in an 87-year-old male. Two carriers of compound C634Y/V292M trans variant had bilateral MTC with pheochromocytoma or lymph node metastasis (age: 54 and 41 years, respectively). Further, the compound C634Y/V292M variant had a faster migration rate than either single point mutation in vitro (P < .05). In conclusion, the V292M RET variant could be classified as 'likely benign' according to ACMG (2015). The compound variant V292M/C634Y was associated with both more aggressive clinical phenotype and faster cell growth in vitro than was either single mutation.

MEN2-related pheochromocytoma: current state of knowledge, specific characteristics in MEN2B, and perspectives

Multiple endocrine neoplasia type 2 (MEN2) is a rare hereditary syndrome due to mutations of the proto-oncogene REarranged during Transfection (RET), defined by the association of medullary thyroid carcinoma (MTC) in almost 100% cases, and pheochromocytoma in roughly 50% (primary hyperparathyroidism can be seen in 10-20% of patients with MEN2A). Early thyroidectomy and the efficacy of novel tyrosine kinase inhibitors modified the natural history of MTC, with possibilities of cure or long-term control. The second main compound, pheochromocytoma, is reported with a variable penetrance, from 10 to 80% cases, depending on the mutation of RET. Pheochromocytoma constitutes the main disease to screen in patients with RET mutations. Pheochromocytoma clinical and biochemical diagnosis, as well as the way to treat it are thus crucial. This review will thus focus on the epidemiological specificities of MEN2-related pheochromocytoma, the genotype/phenotype relationship, the modern imaging modalities necessary to confirm the diagnosis in this hereditary context, as well as the optimal management and the possibilities of adrenal sparing surgery. Additional information will include the natural history of MEN2B-pheochromocytoma, the rare cases of malignant pheochromocytoma, and the factors that could modify the penetrance between individuals carrying the same mutation, especially in the same family.

Survival and Long-Term Biochemical Cure in Medullary Thyroid Carcinoma in Denmark 1997-2014: A Nationwide Study

BACKGROUND

Survival of medullary thyroid carcinoma (MTC) subgroups in relation to the general population is poorly described. Data on the factors predicting long-term biochemical cure in MTC patients are nonexistent at a population level. A nationwide retrospective cohort study of MTC in Denmark from 1997 to 2014 was conducted, aiming to detect subgroups with survival similar to that of the general population and to identify prognostic factors for disease-specific survival and long-term biochemical cure.

METHODS

The study included 220 patients identified from the nationwide Danish MTC cohort between 1997 and 2014. As a representative sample of the general population, a reference population matched 50:1 to the MTC cohort was used.

RESULTS

Patients diagnosed with hereditary MTC by screening (hazard ratio [HR] = 1.5 [confidence interval (CI) 0.5-4.3]), patients without regional metastases (HR = 1.4 [CI 0.9-2.3]), and patients with stage I (HR = 1.3 [CI 0.6-3.1]), stage II (HR = 1.1 [CI 0.6-2.3]), and III (HR = 1.3 [CI 0.4-4.2]) disease had an overall survival similar to the reference population. On multivariate analysis, the presence of distant metastases (HR = 12.3 [CI 6.0-25.0]) predicted worse disease-specific survival, while the absence of regional lymph node metastases (odds ratio = 40.1 [CI 12.0-133.7]) was the only independent prognostic factor for long-term biochemical cure.

CONCLUSIONS

Patients with hereditary MTC diagnosed by screening, patients without regional metastases, and patients with stages I, II, and III disease may have similar survival as the general population. The presence of distant metastases predicted worse disease-specific survival, while the absence of regional metastases predicted long-term biochemical cure.

Long-term follow-up of RET Y791F carriers in Denmark 1994-2017: A National Cohort Study

BACKGROUND AND OBJECTIVES

Recently, a comprehensive study presented evidence that a long-disputed REarranged during Transfection (RET) variant, RET Y791F, should be classified as nonpathogenic. In spite of this, several subsequently published papers, including the revised American Thyroid Association guidelines for medullary thyroid carcinoma, refer to the variant as pathogenic. This study presents data from a unique national Danish cohort of RET Y791F carriers who have been followed by watchful waiting instead of being subjected to early thyroidectomy, to determine if any carrier shows evidence of multiple endocrine neoplasia 2A (MEN2A) at long-term follow-up.

METHODS

A national cohort of all patients tested for RET mutations in Denmark from September 1994 to October 2017 was searched for carriers of RET Y791F. Medical records and laboratory reports of carriers were reviewed for signs of MEN2A at latest follow-up (medullary thyroid carcinoma, primary hyperparathyroidism, pheochromocytoma, cutaneous lichen amyloidosis, or Hirschsprung's disease).

RESULTS

In total, twenty RET Y791F-carriers were identified, none of whom showed any evidence of MEN2A, despite an age range from 7 to 87 years.

CONCLUSIONS

Our national cohort study of all Danish RET Y791F carriers substantiates the claim that the RET Y791F variant is nonpathogenic.