Aggressive variants of follicular cell-derived thyroid carcinoma: an overview

A Comprehensive Review and Insights into the New Entity of Differentiated High-Grade Thyroid Carcinoma

Differentiated high-grade thyroid carcinoma (DHGTC) is a new subset within the spectrum of thyroid malignancies. This review aims to provide a comprehensive overview of DHGTC, focusing on its historical perspective, diagnosis, clinical characteristics, molecular profiles, management, and prognosis. DHGTC demonstrates an intermediate prognosis that falls between well-differentiated thyroid carcinoma and anaplastic thyroid carcinoma. Previously unenumerated, this entity is now recognized for its significant impact. Patients with DHGTC often present at an older age with advanced disease and exhibit aggressive clinical behavior. Molecularly, DHGTC shares similarities with other thyroid malignancies, harboring driver mutations such as BRAFV600E and RAS, along with additional late mutations. The unique behavior and histologic features of DHGTC underscore the necessity of precise classification for prognostication and treatment selection. This highlights the critical importance of accurate diagnosis and recognition by pathologists to enrich future research on this entity further.

Poorly differentiated thyroid carcinoma: molecular, clinico-pathological hallmarks and therapeutic perspectives

Poorly differentiated thyroid carcinoma (PDTC) is a rare and extremely aggressive tumor, accounting for about 2-15% of all thyroid cancer. PDTC has a distinct biological behavior compared to well-differentiated and anaplastic thyroid carcinoma and, in last years, it has been classified as a separate entity from both anatomopathological and clinical points of view. Nevertheless, there is still a lack of consensus among clinicians regarding inclusion criteria and definition of PDTC that affects its diagnosis and clinical management. Due to its rarity and difficulty in classification compared to other tumors, very few studies are available to date and series often include different histotypes in addition to PDTC. This review focuses on main studies concerning PDTC summarizing the evolution in the definition of its diagnosis criteria, clinicopathological features, management, and outcome. The data available confirm that the pathological evaluation and classification of PDTC are crucial and should therefore be standardized. Since the clinical presentation and prognosis of PDTC may vary widely depending on the different stage of the disease at diagnosis, the patient's management may differ in treatment and should be tailored to each patient. Finally, this review discusses advances in molecular insights of PDTC that, together with the implementation of both in vitro and in vivo models, will provide valuable insights into biological mechanisms of progression, metastasis, and invasion of this aggressive thyroid carcinoma. Further studies on larger, carefully selected series are needed to better assess the peculiar features of PDTC and to better define its management by focusing on the best diagnostic and therapeutic approaches.

Papillary thyroid carcinoma: ≤ 10 mm does not always mean pN0. A multicentric real-world study

The incidence of papillary thyroid carcinoma (PTC) is increasing and PTC ≤ 10 mm (PTMC) accounts for most new diagnoses. PTMCs are not always low risk, as detection of lymph nodes metastasis (LNM) may occur. The purpose of the study was to analyze the clinical pattern, frequency, and independent risk factors of patients with PTMC and LNM. From January 2022 to June 2023, PTCs managed at CTO Hospital, Rome; Policlinico Vanvitelli, Naples; and Garibaldi Nesima Hospital, Catania were included. PTC management followed the same diagnostic-therapeutic procedures according to the ATA guidelines. Variables such as age, sex, maximum diameter, histologic evidence of LNM (HELNM +), Hashimoto's thyroiditis (HT), multifocality, capsule invasion, and histological subtype were considered. PTCs were divided according to HELNM and size. Two hundred ninety-eight PTCs were included. PTMCs were 136 (45.6%) and LNM occurred in 27.2% of them. In the HELNM + group, analysis of PTMC vs 'MacroPTC' (PTC > 10 mm) did not show any statistical difference. Multivariate regression revealed that young age (OR 0.93; CI 95% 0.90-0.96; p < 0.01) and male sex (male OR 3.44; CI 95% 1.16-10.20; p = 0.03) were the only independent risk factors for HELNM + in PTMC. The risk of LNM in PTMC is not negligible; therefore, a careful evaluation by an expert thyroidologist is mandatory for patients with small thyroid nodule, especially in younger and male patients before excluding surgery. In the future, new tools are needed to detect early PTMC with LNM before surgery.

Correlation analysis between BRAFV600E mutation and ultrasonic and clinical features of papillary thyroid cancer

Purpose

The study investigates the value of the BRAFV600E mutation in determining the aggressiveness of papillary thyroid cancer (PTC) and its correlation with ultrasound features.

Methods

The study selected 176 patients with BRAFV600E mutation and 80 without the mutation who underwent surgery at Guangxi Medical University Cancer Hospital. Clinical and pathological data were collected, focusing on BRAFV600E mutations and associated ultrasonic features. Correlation analysis, as well as univariate and multivariate logistic regression analysis, were conducted to identify independent risk factors for BRAFV600E mutation. The results were verified using a nomogram model.

Results

The analysis results indicate that the BRAFV600E mutation correlates with tumor size, nodule size, taller-than-wide shape, margin, and shape of papillary thyroid cancer. The receiver operating characteristic curve was used to analyze the diagnostic effect of these features on BRAFV600E mutation. The results showed that nodule size had the most significant area under the curve (AUC = 0.665). Univariate and multivariate logistic regression analyses revealed that taller-than-wide shape ≥1, ill-defined margin, irregular shape, nodule size (≤1.40 cm), TT4 (>98.67 nmol/L), and FT3 (<4.14 pmol/L) were independent risk factors for BRAFV600E mutation. While considering all these factors in the nomogram, the Concordance index (C-index) remained high at 0.764. This suggests that the model has a good predictive effect.

Conclusion

Ultrasound features including nodule size, taller-than-wide shape ≥1, ill-defined margins, irregular shape, higher TT4 levels, and lower FT3 levels were associated with papillary thyroid cancer aggressiveness and BRAFV600E mutation.

Papillary Thyroid Cancer Remodels the Genetic Information Processing Pathways

The genetic causes of the differentiated, highly treatable, and mostly non-fatal papillary thyroid cancer (PTC) are not yet fully understood. The mostly accepted PTC etiology blames the altered sequence or/and expression level of certain biomarker genes. However, tumor heterogeneity and the patient's unique set of favoring factors question the fit-for-all gene biomarkers. Publicly accessible gene expression profiles of the cancer nodule and the surrounding normal tissue from a surgically removed PTC tumor were re-analyzed to determine the cancer-induced alterations of the genomic fabrics responsible for major functional pathways. Tumor data were compared with those of standard papillary and anaplastic thyroid cancer cell lines. We found that PTC regulated numerous genes associated with DNA replication, repair, and transcription. Results further indicated that changes of the gene networking in functional pathways and the homeostatic control of transcript abundances also had major contributions to the PTC phenotype occurrence. The purpose to proliferate and invade the entire gland may explain the substantial transcriptomic differences we detected between the cells of the cancer nodule and those spread in homo-cellular cultures (where they need only to survive). In conclusion, the PTC etiology should include the complex molecular mechanisms involved in the remodeling of the genetic information processing pathways.

Management of aggressive variants of papillary thyroid cancer

PURPOSE OF REVIEW

The aim of this study was to provide a timely and relevant review of the latest findings and explore appropriate management of aggressive variants of papillary thyroid cancer (AVPTC).

RECENT FINDINGS

In general, AVPTCs tend to exhibit more invasive characteristics, a lack of responsiveness to radioiodine, increased occurrences of regional spreading, distant metastases and higher mortality rates. Meanwhile, each variant showcases unique clinical and molecular profiles.

SUMMARY

Given the elevated risk of recurrence postsurgery, a more aggressive strategy may be necessary when suspected preoperatively, particularly for those presenting with invasive features. Decision on the extent of surgical treatment and adjuvant therapy is individualized and made by experienced clinicians and multidisciplinary teams based on the clinical presentation, presence of aggressive features and molecular profile. Future studies on development of personalized medicine and molecular target therapy may offer tailored treatment options.

Are Higher Body Mass Index and Worse Metabolic Parameters Associated with More Aggressive Differentiated Thyroid Cancer? A Retrospective Cohort Study

Obesity is a risk factor for differentiated thyroid cancer (DTC), but the association with DTC aggressiveness is controversial. To evaluate the association between preoperative body mass index (BMI)/other metabolic parameters and DTC aggressiveness in our surgical cohort, we retrospectively evaluated patients following thyroid surgery who were diagnosed with DTC between December 2013 and January 2021. Baseline characteristics, histopathological features, treatment modalities, and follow-up data were studied. We conducted logistic regression to analyze the association between BMI/other metabolic parameters and adverse DTC features. The final study cohort included 211 patients (79.6% women; mean age± standard deviation 48.7 ± 15.9 years): 66 (31.3%) with normal weight, 81 (38.4%) with overweight, and 64 (30.3%) with obesity. The median follow-up was 51 months (range 7-93). Complete versus partial thyroidectomy was more common among patients living with overweight or obesity than in normal weight patients (79.7% versus 61.7%, p = 0.017, respectively). Logistic regression demonstrated that higher BMI was associated with mildly increased risk for lymph nodes metastases (odds ratio [OR] 1.077, 95% CI: 1.013-1.145), and higher triglycerides/high-density lipoprotein-cholesterol (TG/HDL-C) ratio was associated with aggressive histological variants of DTC (OR 1.269, 95% CI 1.001-1.61). To conclude, specific adverse clinical and histopathological DTC features were indeed associated with higher BMI and higher TG/HDL-C ratio.

Artificial Intelligence Detected the Relationship Between Nuclear Morphological Features and Molecular Abnormalities of Papillary Thyroid Carcinoma

Papillary thyroid carcinoma (PTC) is the most common type of thyroid carcinoma and has characteristic nuclear features. Genetic abnormalities of PTC affect recent molecular target therapeutic strategy towards RET-altered cases, and they affect clinical prognosis and progression. However, there has been insufficient objective analysis of the correlation between genetic abnormalities and nuclear features. Using our newly developed methods, we studied the correlation between nuclear morphology and molecular abnormalities of PTC with the aim of predicting genetic abnormalities of PTC. We studied 72 cases of PTC and performed genetic analysis to detect BRAF p.V600E mutation and RET fusions. Nuclear features of PTC, such as nuclear grooves, pseudo-nuclear inclusions, and glassy nuclei, were also automatically detected by deep learning models. After analyzing the correlation between genetic abnormalities and nuclear features of PTC, logistic regression models could be used to predict gene abnormalities. Nuclear features were accurately detected with over 0.90 of AUCs in every class. The ratio of glassy nuclei to nuclear groove and the ratio of pseudo-nuclear inclusion to glassy nuclei were significantly higher in cases that were positive for RET fusions (p = 0.027, p = 0.043, respectively) than in cases that were negative for RET fusions. RET fusions were significantly predicted by glassy nuclei/nuclear grooves, pseudo-nuclear inclusions/glassy nuclei, and age (p = 0.023). Our deep learning models could accurately detect nuclear features. Genetic abnormalities had a correlation with nuclear features of PTC. Furthermore, our artificial intelligence model could significantly predict RET fusions of classic PTC.

Construction and validation of a nomogram for predicting cervical lymph node metastasis in diffuse sclerosing variant of papillary thyroid carcinoma

OBJECTIVE

To analyze the risk factors associated with the occurrence of cervical lymph node metastasis (LNM) in patients with diffuse sclerosing variant of papillary thyroid carcinoma (DSV-PTC) and to establish a nomogram model.

METHODS

Clinical data of 199 DSV-PTC patients from SEER database were obtained, and they were randomly divided into training group (n=139) and validation group (n=60). The clinicopathological characteristics were analyzed by logistic regression, including age, marital status, race, gender, tumor size(cm), T stage, M stage, bilaterality, capsular invasion, extrathyroidal extension (ETE), and multifocality. The Validation was carried out using C-index, calibration curves, and Decision Curve Analysis (DCA) in terms of differentiation and calibration of the nomogram model, respectively.

RESULTS

Age, tumor size(cm), capsular invasion, and multifocality were independent risk factors for the development of LNM in patients with DSV-PTC (P<0.05). In the training and validation groups, the C-index of internal validation of the nomogram was 0.808 (95%CI: 0.733-0.755) and 0.813 (95% CI: 0.591-0.868), the calibration curves showed that the model was in good agreement, and the decision curve (DCA) indicated that the nomogram model had good clinical utility.  CONCLUSION: Age, tumor size(cm), capsular invasion, and multifocality are independent risk factors for the development of LNM in DSV-PTC. The nomogram model can predict the risk of developing LNM in DSV-PTC patients and provide clinical guidance.

Diffuse Sclerosing Variant of Papillary Thyroid Carcinoma Is Related to a Poor Outcome: A Comparison Study Using Propensity Score Matching

OBJECTIVE

The clinical outcome of diffuse sclerosing variant of papillary thyroid carcinoma (DSV-PTC) remains controversial. We aimed to determine whether DSV-PTC is associated with an increased risk of persistent/recurrent disease.

METHODS

We performed a retrospective cohort study of DSV-PTC and classic variant of papillary thyroid carcinoma (CV-PTC) after postoperative radioactive iodine therapy. We used propensity score matching (1:3 matching ratio) to account for differences between the recipients of DSV-PTC and CV-PTC. Univariate and multivariate analyses were performed to assess the independent factors for persistent/recurrent disease. The Kaplan-Meier curve analyses were used to compare disease-free survival (DFS).

RESULTS

In total, 35 (12.7%) patients with DSV-PTC and 240 (87.3%) patients with CV-PTC were included. After propensity score matching, 35 pairs of patients were selected (DSV-PTC, n = 35; CV-PTC, n = 105). In the matched analysis, a higher proportion of patients with DSV-PTC experienced persistent/recurrent disease than that of those with CV-PTC (25.7% vs 5.7%, P = .003). In the multivariate analyses of clinical and tumor characteristics, only the histologic type of DSV-PTC (odds ratio, 6.288; 95% confidence interval, 1.900-20.811; P = .003) was associated with an increased risk of persistent/recurrent disease. The 5-year DFS rates for the DSV-PTC and CV-PTC groups were 69.2% and 93.6%, respectively. The Kaplan-Meier analysis indicated that the DSV-PTC group (P= .001) had shorter DFS.

CONCLUSION

This propensity score-matched analysis found that the histologic type of DSV-PTC may increase the risk of persistent/recurrent disease.

Circ_0011373 promotes papillary thyroid carcinoma progression by regulating miR-1271/LRP6 axis

PURPOSE

This research aimed to explore the regulatory molecular mechanism among circular RNA (circ)_0011373, microRNA (miR)-1271, and lipoprotein receptor-related protein 6 (LRP6) in papillary thyroid carcinoma (PTC).

METHODS

Quantitative real-time PCR (qRT-PCR) assay was adopted to measure the expression of circ_0011373, miR-1271, and LRP6 mRNA. Furthermore, cell cycle distribution, apoptosis, migration and invasion were investigated by flow cytometry and transwell assay, respectively. The target relationship between miR-1271 and circ_0011373 or LRP6 was predicted by using the Starbase website and DIANA TOOL and verified by dual-luciferase reporter and RIP assay. Protein expression levels of LRP6, p-mTOR, mTOR, p-AKT, AKT, p-PI3K, and PI3K were tested by Western blot. The function of circ_0011373 on PTC tumor growth was validated by the xenograft tumor model in vivo.

RESULTS

Circ_0011373 and LRP6 were upregulated, while miR-1271 was downregulated in PTC tissues and cell lines. Moreover, knockdown of circ_0011373 inhibited cell cycle, migration, and invasion and promoted apoptosis. Of particular importance was the fact that circ_0011373 directly interacted with miR-1271 and miR-1271 inhibitor was able to reverse the effect of circ_0011373 knockdown on PTC cell progression. Meanwhile, LRP6 was directly targeted by miR-1271, and its expression was positively regulated by circ_0011373. We further confirmed that miR-1271 overexpression suppressed cell cycle, migration, and invasion and enhanced apoptosis by regulating LRP6. In addition, circ_0011373 knockdown restrained PTC tumor growth in vivo.

CONCLUSION

Circ_0011373 might be able to regulate PTC cell cycle, migration, invasion, and apoptosis by regulating the miR-1271/LRP6 axis.

Molecular Genetics of Diffuse Sclerosing Papillary Thyroid Cancer

CONTEXT

Diffuse sclerosing papillary thyroid cancer (DSPTC) is rare, with limited data on its molecular genetics.

OBJECTIVE

We studied the molecular genetics of a cohort of DSPTC.

METHODS

DNA was isolated from paraffin blocks of 22 patients with DSPTC (15 females, 7 males, median age 18 years, range 8-81). We performed polymerase chain reaction-based Sanger sequencing and a next-generation sequencing (NGS) gene panel to characterize the genomic landscape of these tumors. We classified genetic alterations to definitely or probably pathogenic. Definitely pathogenic are genetic alterations that are well known to be associated with PTC (e.g., BRAFV600E). Probably pathogenic are other alterations in genes that were reported in The Cancer Genome Atlas or the poorly differentiated and anaplastic thyroid cancer datasets.

RESULTS

Three tumors were tested only by Sanger sequencing and were negative for BRAFV600E, HRAS, KRAS, NRAS, TERT promoter, PTEN, and PIK3CA mutations. The other 19 tumors tested by NGS showed definitely pathogenic alterations in 10 patients (52.6%): 2/19 (10.5%) BRAFV600E, 5/19 (26.3%) CCDC6-RET (RET/PTC1), 1/19 (5.3%) NCOA4-RET (RET/PTC3), 1/19 (5.3%) STRN-ALK fusion, and 2/19 (10.6%) TP53 mutations. Probably pathogenic alterations occurred in 13/19 tumors (68.4%) and included variants in POLE (31.6%), CDKN2A (26%), NF1 (21%), BRCA2 (15.8%), SETD2 (5.3%), ATM (5.3%), FLT3 (5.3%), and ROS1 (5.3%). In 1 patient, the gene panel showed no alterations. No mutations were found in the RAS, PTEN, PIK3CA, or TERT promoter in all patients. There was no clear genotype/phenotype correlation.

CONCLUSION

In DSPTC, fusion genes are common, BRAFV600E is rare, and other usual point mutations are absent. Pathogenic and likely pathogenic variants in POLE, NF1, CDKN2A, BRCA2, TP53, SETD2, ATM, FLT3, and ROS1 occur in about two-thirds of DTPTC.

High-Grade Non-Anaplastic Thyroid Carcinomas of Follicular Cell Origin: A Review of Poorly Differentiated and High-Grade Differentiated Carcinomas

Poorly differentiated thyroid carcinoma (PDTC) and high-grade differentiated thyroid carcinoma (HGDTC) are considered high-grade follicular-derived thyroid carcinomas, with prognoses intermediate between well-differentiated and anaplastic thyroid carcinoma. Both share the presence of invasion, thyroid follicular-cell origin, and tumor necrosis or increased mitoses (≥ 3 mitoses per 2 mm² in PDTC and ≥ 5 mitoses per 2 mm² in HGDTC), without anaplastic dedifferentiation. PDTC must possess solid, trabecular, or insular growth and lack classic papillary-like nuclei; HGDTC can be of any architectural or nuclear morphology (follicular-like, papillary-like, oncocytic). Transformation may be accompanied by acquisition of high-risk mutations (such as TP53 or TERT promoter) on top of RAS-like or BRAF p.V600E-like (including NTRK-fusion) initial driver mutations. These carcinomas most frequently affect adults and often present with metastases (20-50%) or wide local invasion. As PDTC and HGDTC may be radioactive iodine resistant, post-surgical therapy may consist of external beam radiotherapy or targeted, mutation-dependent chemotherapy, such as tyrosine kinase inhibitors. Ten-year disease specific survival is as low as 50%. Awareness of high-grade features in the diagnostic setting is important for patient prognosis and triage of tissue for molecular analysis in order to guide relevant clinical management and therapy.