Presence of TERT ± BRAF V600E mutation is not a risk factor for the clinical management of patients with papillary thyroid microcarcinoma

Papillary microcarcinoma of the thyroid gland: Evaluation of TERT and BRAFV-600E expression and their relationship with clinicopathological findings

Papillary microcarcinomas (PMCs) are papillary carcinomas ≤1 cm in size, with an increasing incidence. Although generally indolent, some cases exhibit aggressive behavior. Recently, active surveillance has been recommended to avoid surgical treatment. Identifying molecular changes that predict aggressiveness in PMCs has gained importance, but studies are limited. We aimed to demonstrate TERT expression and BRAF V600E positivity immunohistochemically in PMCs and correlate them with histomorphological features, subtypes, and clinicopathological findings. We included 95 PMC cases diagnosed between 2010 and 2019 at the Department of Pathology, Faculty of Medicine, XXX University. We investigated TERT expression using RT-PCR. We evaluated BRAF V600E mutation immunohistochemically. We evaluated the relationship between genetic, histomorphological, and clinicopathological findings. In patients with multifocality and those with a tumor size ≥0.5 cm, the frequency of lymph node metastasis was significantly higher. A positive correlation was shown between BRAF V600E positivity and lymph node metastasis, lymphovascular invasion, advanced disease stage, and classical subtype by univariate analyses. We detected TERT expression in 18 of 95 patients (7.8 %). No relationship could be detected between TERT expression alone or combined with BRAF positivity and clinicopathological features. Although TERT mutations are associated with aggressiveness in thyroid cancers, this association was absent in PMCs. The presence of TERT expression was demonstrated in some cases. However, TERT expression could not be associated with clinicopathological findings, which is consistent with the literature suggesting that TERT plays a role in advanced stages of carcinogenesis.

Genomic characterization of cervical lymph node metastases in papillary thyroid carcinoma following the Chornobyl accident

Childhood radioactive iodine exposure from the Chornobyl accident increased papillary thyroid carcinoma (PTC) risk. While cervical lymph node metastases (cLNM) are well-recognized in pediatric PTC, the PTC metastatic process and potential radiation association are poorly understood. Here, we analyze cLNM occurrence among 428 PTC with genomic landscape analyses and known drivers (131I-exposed = 349, unexposed = 79; mean age = 27.9 years). We show that cLNM are more frequent in PTC with fusion (55%) versus mutation (30%) drivers, although the proportion varies by specific driver gene (RET-fusion = 71%, BRAF-mutation = 38%, RAS-mutation = 5%). cLNM frequency is not associated with other characteristics, including radiation dose. cLNM molecular profiling (N = 47) demonstrates 100% driver concordance with matched primary PTCs and highly concordant mutational spectra. Transcriptome analysis reveals 17 differentially expressed genes, particularly in the HOXC cluster and BRINP3; the strongest differentially expressed microRNA also is near HOXC10. Our findings underscore the critical role of driver alterations and provide promising candidates for elucidating the biological underpinnings of PTC cLNM.

TERT RNAscope analysis of sub-centimetric papillary thyroid carcinomas and synchronous lymph node metastases

BACKGROUND

Sub-centrimetric papillary thyroid carcinomas usually have a good prognosis with a cancer specific survival of > 99%, however in up to 65% of patients, lymph node metastases can be observed. Molecular alterations in BRAF, TERT and TP53 are associated with worse clinicopathological outcome in patients with papillary thyroid carcinoma.

MATERIAL AND METHODS

Twenty-two cases of papillary thyroid carcinomas measuring ≤ 1 cm with synchronous lymph node metastases were examined regarding morphological patterns and immunohistochemical status of p53, Ki-67, and BRAF V600E status. TERT RNA expression in lymph node metastases were evaluated by RNAScope®.

RESULTS

Morphological patterns were heterogeneous in both primary tumors and lymph node metastases. Proliferation indices measured by Ki-67 were low. Both primary and lymph node metastases were wild type for p53 by immunohistochemical analysis. No lymph node metastasis showed TERT expression by RNAScope®.

CONCLUSIONS

Our data indicate that TERT expression is not involved in the development early lymph node metastasis in patients with sub-centimetric PTC.

Mortality rate and causes of death in papillary thyroid microcarcinoma

PURPOSE

Papillary thyroid microcarcinoma (PTMC) has an excellent prognosis; however, some PTMCs exhibit poor outcomes. Cancer-specific death from PTMC has been rarely reported, so we aimed to evaluate mortality rates and causes of death in patients who died with PTMC.

METHODS

We retrospectively reviewed 8969 PTMC patients treated at Samsung Medical Center from 1994 to 2017. Mortality rate and causes of death in PTMC patients were evaluated and compared with those of 7873 patients with papillary thyroid carcinoma (PTC) > 1 cm. In addition, we reviewed previous publications reporting cancer-specific deaths from PTMC.

RESULTS

Among the 8969 PTMC patients, 107 (1.2%) patients died. Only two (0.02%) patients have died of PTMC, which was less than the cancer-specific deaths from PTC > 1 cm (0.71%). Among the deceased PTMC patients, 63 (58.9%) died of other malignancies, three (2.8%) died of cardiovascular diseases, and five (4.7%) died of other diseases. Compared with PTC > 1 cm, cancer-specific deaths was less (1.9% vs. 15.1%, P < 0.001), and deaths from other malignancies were higher in deceased PTMC patients (58.9% vs. 30.5%, P < 0.001). According to 18 studies, PTMC-specific mortality rates ranged from 0.05% to 14.3%, and 336 cancer-specific deaths (0.43%) occurred among 78,770 PTMC patients.

CONCLUSION

The cancer-specific mortality rate of PTMC patients was extremely low (0.02%). More than half of deceased PTMC patients died of other malignancies, which was significantly more than those with PTC > 1 cm. These results support that active surveillance can be selected as a therapeutic option for PTMC.

Recommend with caution: A meta-analysis investigating papillary thyroid carcinoma tumor progression under active surveillance

BACKGROUND

Papillary thyroid carcinoma (PTC) is an indolent disease with favorable outcomes. The non-surgical treatment approach known as active surveillance (AS) has been introduced as an alternative treatment instead of the traditional thyroidectomy. However, 10-15 % of PTC tend to progress. We sought to determine factors predicting the progression of PTC under AS.

METHODS

A systematic search was performed in January 2022 using PubMed, Embase, Google Scholar, Web of Science, and ScienceDirect. PRISMA guidelines were used by multiple reviewers to extract study characteristics (author name, publication date, journal name, country, institution, and study design), as well as main outcomes and measures. A combination of utilization of thyroid replacement therapy, baseline tumor size and volume, follow-up tumor size and volume, and the presence of lymph node metastasis and its distribution, as well as surveillance duration, were the main measures of this study.

RESULTS

Nine studies with 4166 patients were included, of which 354 showed tumor progression during AS (15 %; 95%CI = 7 % - 23 %). The average follow-up period was 41.58 months. The mean tumor maximum diameter was 8.54 mm (95%CI = 7.04-10.03). Tumor progression was most commonly secondary to an increase in volume by ≥50 % (75 %; 95%CI = 68 % - 80 %), then increase in diameter by ≥3 mm (41 %; 95%CI = 13 % - 76 %), and finally the development of lymph node metastasis (13 %; 95%CI = 9 % - 19 %). Approximately only 2 % of all patients thus developed new lymph node metastasis. Patient age, sex, and tumor size were not associated with higher risks of tumor progression. 12 % of AS patients eventually underwent surgery, though only 40 % (95%CI = 27 % - 53 %) of these patients displayed tumor progression.

CONCLUSIONS

Our meta-analysis determined a tumor progression rate of 15 % in patients who underwent AS management, 13 % of which (2 % of all patients) developed lymph node metastasis. We found no protective or risk factors for tumor progression, and that almost half of all patients who underwent delayed surgery did so for reasons other than tumor progression. While not biopsying small (<1 cm) or very low suspicious nodules is already recommended, AS may be an appropriate treatment option in patients appropriately counseled, considering the low risk of advanced tumor progression but also the considerable patient population who fail to adhere to treatment. Alternatively, in aim of preventing overtreatment in patients who would rather take proactive measures against their low-risk carcinoma, minimally-invasive ablation techniques may be an attractive option.

Active surveillance of low-risk papillary thyroid microcarcinoma

Recently, the incidence of thyroid carcinoma has been increasing rapidly worldwide. This is interpreted as an increase in the incidental detection of small papillary thyroid carcinomas by the widespread use of high-resolution imaging techniques such as ultrasonography. However, the mortality rates of thyroid carcinoma have not changed, suggesting that small papillary thyroid carcinomas may be overdiagnosed and overtreated. Active surveillance management has been introduced from Japan since the 1990s, as one of the measures to prevent overtreatment of low-risk papillary thyroid microcarcinoma. Based on the favorable outcomes, active surveillance has been gradually adopted worldwide as an alternative to immediate surgery. The management should be carried out with strict eligibility criteria and close monitoring for cancer progression, under a multidisciplinary team. In addition, an adequate shared decision-making is mandatory for individual patients. Papillary thyroid microcarcinomas with clinically apparent lymph node metastasis, distant metastasis, or invasion to adjacent organs should have surgery.

A Significance of Concomitant BRAFV600E and TERT Mutations in Polish Patients with Papillary Thyroid Microcarcinoma: A Retrospective Cohort Study Based on 430 Cases

Background: The incidence of papillary thyroid cancer is increasing worldwide due to more frequent pathological detection of papillary thyroid microcarcinomas (PTMC), which are cancers measuring 1 cm or less in diameter. In rare cases, the course of PTMC can be aggressive, with an increased risk of recurrence/persistent disease. The aim of this study of Polish patients diagnosed with PTMC was to assess the impact of concomitant B-type Raf kinas-activating mutation in codon 600 of exon 15 (BRAF^V600E) and telomerase reverse transcriptase (TERT) hotspot mutations on clinicopathological features, response to treatment, potential recurrence, and the final outcome. Methods: A retrospective analysis of the 430 PTMC cases diagnosed during 2001-2020 at a single center was performed. All PTMC cases were assessed histopathologically, and analyses of BRAF^V600E and TERT promoter were performed based on DNA isolated from tumor blocks. Results: There were 29/430 (6.7% [confidence interval: 4.6-9.5]) patients in whom the TERT^C228T and/or TERT^C250T mutations coexisted with the BRAF^V600E mutation. A statistical comparison between PTMC cases with concomitant BRAF^V600E and TERT hotspot mutations and those without any of those mutations revealed no significant differences between the two groups with respect to risk stratification, response to primary treatment, clinical course, or final disease status. Conclusion: Regardless of the molecular background of PTMC, the overall response to therapy is excellent, and long-term disease-free survival rates can be achieved by most patients.

Clair J, Chen MM, Vasquez M, Fan X, van Deen WK, Haile RW, Daskivich TJ, Zumsteg ZS, Braunstein GD, Sacks WL. Expanded Parameters in Active Surveillance for Low-risk Papillary Thyroid Carcinoma: A Nonrandomized Controlled Trial

Importance

Unlike for prostate cancer, active surveillance for thyroid cancer has not achieved wide adoption. The parameters by which this approach is feasible are also not well defined, nor is the effect of patient anxiety.

Objective

To determine if expanded size/growth parameters for patients with low-risk thyroid cancer are viable, as well as to assess for cohort differences in anxiety.

Design, Setting, and Participants

This prospective nonrandomized controlled trial was conducted at a US academic medical center from 2014 to 2021, with mean [SD] 37.1 [23.3]-month follow-up. Of 257 patients with 20-mm or smaller Bethesda 5 to 6 thyroid nodules, 222 (86.3%) enrolled and selected treatment with either active surveillance or immediate surgery. Delayed surgery was recommended for size growth larger than 5 mm or more than 100% volume growth. Patients completed the 18-item Thyroid Cancer Modified Anxiety Scale over time.

Interventions

Active surveillance.

Main Outcomes and Measures

Cumulative incidence and rate of size/volume growth.

Results

Of the 222 patients enrolled, the median (IQR) age for the study population was 46.8 (36.6-58) years, and 76.1% were female. Overall, 112 patients (50.5%) underwent treatment with active surveillance. Median tumor size was 11.0 mm (IQR, 9-15), and larger tumors (10.1-20.0 mm) comprised 67 cases (59.8%). One hundred one (90.1%) continued to receive treatment with active surveillance, 46 (41.0%) had their tumors shrink, and 0 developed regional/distant metastases. Size growth of more than 5 mm was observed in 3.6% of cases, with cumulative incidence of 1.2% at 2 years and 10.8% at 5 years. Volumetric growth of more than 100% was observed in 7.1% of cases, with cumulative incidence of 2.2% at 2 years and 13.7% at 5 years. Of 110 patients who elected to undergo immediate surgery, 21 (19.1%) had equivocal-risk features discovered on final pathology. Disease severity for all such patients remained classified as stage I. Disease-specific and overall survival rates in both cohorts were 100%. On multivariable analysis, immediate surgery patients exhibited significantly higher baseline anxiety levels compared with active surveillance patients (estimated difference in anxiety scores between groups at baseline, 0.39; 95% CI, 0.22-0.55; P < .001). This difference endured over time, even after intervention (estimated difference at 4-year follow-up, 0.50; 95% CI, 0.21-0.79; P = .001).

Conclusions and Relevance

The results of this nonrandomized controlled trial suggest that a more permissive active surveillance strategy encompassing most diagnosed thyroid cancers appears viable. Equivocal-risk pathologic features exist in a subset of cases that can be safely treated, but suggest the need for more granular risk stratification. Surgery and surveillance cohorts possess oppositional levels of worry, elevating the importance of shared decision-making when patients face treatment equivalence.

Trial Registration

ClinicalTrials.gov Identifier: NCT02609685.

TERT Promoter Mutations Are an Independent Predictor of Distant Metastasis in Middle Eastern Papillary Thyroid Microcarcinoma

BACKGROUND

Papillary thyroid microcarcinomas (PTMCs) have been attributed to the recent increased incidence of thyroid cancer. Although indolent, a subset of PTMC could potentially develop distant metastasis (DM). This study aimed to evaluate the clinico-pathological features and molecular characteristics of PTMC and identify the risk factors for DM in PTMC patients from Middle Eastern ethnicity.

METHODS

We retrospectively analyzed 210 patients with histologically confirmed PTMC. Clinico-pathological associations for DM, BRAF mutation and TERT mutation were analyzed successfully in 184 patients. Multivariate analysis was performed using Cox proportional hazards model and logistic regression analysis.

RESULTS

Among the PTMC patients included in this cohort, DM was noted in 6.0% (11/184), whereas tumor relapse occurred in 29/184 (15.8%). Of the 11 cases with DM, lung metastasis occurred in 8 cases, bone metastasis in 2 cases and brain metastasis in 1 case. Presence of extrathyroidal extension and male sex were significantly associated with DM. Molecular analysis showed BRAF V600E mutations to be the most frequent, being detected in 45.7% (84/184). TERT promoter mutations were detected in 16 (8.7%) cases and were significantly associated with DM and shorter metastasis-free survival in multivariate analysis.

CONCLUSIONS

Our study indicates a surprisingly high frequency of TERT promoter mutation in Saudi patients with PTMC. Identifying TERT promoter mutations as an independent predictor of DM in patients with microcarcinoma could explain the inherent aggressive nature of PTMC from Middle Eastern ethnicity and magnify its role in patient risk stratification, which might help in improving therapeutic strategy for these patients.

Epigenetic modification and BRAF gene mutation in thyroid carcinoma

Thyroid cancer remains the most prevailing endocrine malignancy, and a progressively increasing incidence rate has been observed in recent years, with 95% of thyroid cancer represented by differentiated thyroid carcinomas. The genetics and epigenetics of thyroid cancer are gradually increasing, and gene mutations and methylation changes play an important roles in its occurrence and development. Although the role of RAS and BRAF mutations in thyroid cancer have been partially clarified,but the pathogenesis and molecular mechanisms of thyroid cancer remain to be elucidated. Epigenetic modification refer to genetic modification that does not change the DNA sequence of a gene but causes heritable phenotypic changes in its expression. Epigenetic modification mainly includes four aspects: DNA methylation, chromatin remodelling, noncoding RNA regulation, and histone modification. This article reviews the importance of thyroid cancer epigenetic modification and BRAF gene mutation in the treatment of thyroid cancer.