Poorly differentiated thyroid carcinoma: a retrospective clinicopathological study

Management of Poorly Differentiated Thyroid Cancer and Differentiated High-Grade Thyroid Carcinoma

Thyroid carcinoma of follicular cell origin exists on a histopathologic and clinical spectrum. The authors focus on the category of tumors that fall between the very favorable well-differentiated thyroid carcinomas and the very unfavorable anaplastic thyroid carcinomas. These intermediately aggressive tumors include poorly differentiated thyroid carcinoma and the newly defined differentiated high-grade thyroid carcinoma. Both diagnoses require certain histopathologic requirements be met in order to accurately identify these tumors post-operatively. Management remains primarily surgical though adjunctive treatments such as molecular targeted therapies (eg, tyrosine kinase inhibitors) and differentiation therapy (to restore tumor response to radioactive iodine) are also becoming available.

Poorly differentiated thyroid carcinomas: conceptual controversy and clinical impact

Poorly differentiated thyroid carcinomas (PDTC) are rare diseases; nevertheless, they account for the majority of deaths from non-anaplastic follicular cell-derived thyroid carcinomas. Establishing the diagnosis and treatment of PDTC is challenging given the low incidence and the lack of standardization of diagnostic criteria. These limitations hamper the ability to compare therapeutic modalities and outcomes between recent and older studies. Recently, the 5th edition of the classification of endocrine tumors has been published, which includes changes in nomenclature and the addition of the disease entity of "differentiated high-grade follicular cell-derived carcinomas". On the other hand, the recently witnessed advances in molecular diagnostics have enriched therapeutic options and improved prognosis for patients. We herein review the various historical variations and evolution in the diagnostic criteria for PDTC. This systematic review attempts to clarify the evolution of the histological and molecular characteristics of this disease, its prognosis, as well as its treatment options.

Predictive factors and clinicopathological characteristics of outcome in poorly differentiated thyroid carcinoma: a single-institution study

Objective

To elucidate the clinicopathological characteristics and prognostic factors of poorly differentiated thyroid carcinoma.

Method

A total of 24912 thyroid carcinoma patients admitted to the First Medical Center of Chinese People's Liberation Army General Hospital from 2005 to 2020 were retrospectively reviewed. A total of 94 patients (39 males and 55 females, a male-female ratio of 1:1.4) fulfilled the selection criteria. Of these, 73 patients had undergone surgery. The clinical and pathological data were collected from each enrolled patient. Univariate and multivariate Cox regression analyses were performed to determine independent prognostic factors. All analyses were performed with the SPSS version 26.0 and R version 1.2.5033 in the R Studio environment.

Results

The specimens included 20 cases of poorly differentiated thyroid carcinoma complicated with papillary thyroid carcinoma, 17 cases complicated with follicular thyroid carcinoma, 34 cases complicated with other pathological types and 23 with a separate entity. The patient demonstrated a large age span, median age was 57 years (range 8-85 years, average 55.20 ± 15.74 years). The survival time of the 94 cases was calculated, and the mean Overall survival time was 33 (range, 1-170) months, and the mean Recurrence-free survival time was 14 (range, 1-90) months. Recurrence-free mortality is related to the age at diagnosis, extrathyroidal extension and Associated thyroid cancer (p<0.05). In contrast, overall mortality is related to the age at diagnosis, sex, extrathyroidal extension, T stage (AJCC 8th), surgery and radiation (p<0.05).

Conclusion

Middle-aged and elderly patients are still at high risk for poorly differentiated thyroid carcinoma. The pathologic results of poorly differentiated thyroid carcinoma are varied, and reasonable treatment has an important impact on the prognosis of poorly differentiated thyroid carcinoma.

Newly proposed survival staging system for poorly differentiated thyroid cancer: a SEER-based study

OBJECTIVE

Despite the recent release of the 8th edition TNM staging system, the risk stratification for poorly differentiated thyroid cancer (PDTC) remains controversial.

STUDY DESIGN

Retrospective study.

SETTING

SEER database and the First Hospital of China Medical University (FHCMU) database.

METHODS

Between 2004 and 2015, 1201 PDTC patients from the SEER database were enrolled to propose a new staging system. 38 PDTC patients were included from the FHCMU.

RESULTS

A retrospective analysis of 1201 PDTC cases was performed, and a new staging classification was developed as follows: stage I: age < 55 and T1/any N/M0 (n = 127, 10.57%); stage II: age < 55 and T2-4/any N/M0 or age ≥ 55 and T1-2/any N/M0 (n = 523, 43.55%); stage III: age < 55 and any T/N0/M1 or age ≥ 55 and any T3/any N/M0 (n = 239, 19.90%); stage IV: age < 55 and any T/N1/M1 or age ≥ 55 and T4/any N/M0, and T/any N/M1 (n = 312, 25.98%). The 10-year disease-specific survival rates of patients in the new stages I, II, III, and IV were 97.9%, 77.9%, 35.3%, and 12.1%, respectively. The proportion of variation explained (PVE) for disease-specific survival of the proposed system was higher than that of the 8th AJCC TNM staging (30.61% vs. 27.15%). The accuracy of the staging system was verified in 38 PDTC patients from the FHCMU.

CONCLUSION

The proposed staging system provided a more accurate risk stratification for PDTC patients. The new staging model may facilitate the design of personalized treatment strategies for PDTC patients.

Unusual Clinical Manifestations of Thyroid Carcinoma

Thyroid cancer is considered the most common endocrine malignancy, with the most frequent presentation of differentiated thyroid cancer being a neck swelling or an incidental finding of a thyroid nodule on imaging. In this case series, we describe three cases of thyroid cancer with unusual clinical manifestations. The first case describes a patient who underwent parathyroidectomy for primary hyperparathyroidism and was found to have papillary thyroid cancer on a cervical lymph node biopsy. While this may be coincidental, the literature raises the question of whether there may be an association. The second case describes a patient who presents with a suspicious thyroid nodule and was subsequently diagnosed with follicular thyroid cancer on biopsy. This raises the question of performing thyroidectomy early in patients with a suspicious thyroid nodule but a false negative biopsy. The third case describes a patient with a scalp lesion found to have poorly differentiated thyroid carcinoma, a rare presentation of this form of cancer.

Poorly differentiated thyroid carcinoma: a clinician's perspective

Poorly differentiated thyroid carcinoma (PDTC) is a rare thyroid carcinoma originating from follicular epithelial cells. No explicit consensus can be achieved to date due to sparse clinical data, potentially compromising the outcomes of patients. In this comprehensive review from a clinician's perspective, the epidemiology and prognosis are described, diagnosis based on manifestations, pathology, and medical imaging are discussed, and both traditional and emerging therapeutics are addressed as well. Turin consensus remains the mainstay diagnostic criteria for PDTC, and individualized assessments are decisive for treatment option. The prognosis is optimal if complete resection is performed at early stage but dismal in nearly half of patients with locally advanced and/or distant metastatic diseases, in which adjuvant therapies such as 131I therapy, external beam radiation therapy, and chemotherapy should be incorporated. Emerging therapeutics including molecular targeted therapy, differentiation therapy, and immunotherapy deserve further investigations to improve the prognosis of PDTC patients with advanced disease.

Revision Thyroid Surgery

The incidence of recurrence in well-differentiated thyroid malignancies range from 10 to 30%. It is estimated that about 31-46% of patients with differentiated thyroid cancer will have the persistent disease and 1.2-6.8% will have structural recurrences during post-operative monitoring, depending on the initial therapy and prognostic variables. It is challenging to decide on treatment versus active monitoring following repeated or persistent tumour detection. The biological factors of the tumour and the patient guide us in the overall decision-making. Revision thyroid surgery is technically challenging. The morbidity encountered during the revision surgery is related to the anatomy of the region undergoing dissection, the degree of fibrosis and scarring from prior surgery and the operating surgeon's experience. Successful comprehensive management of revision thyroid surgery needs a multi-disciplinary approach. This review article highlights the definition, indications for revision surgery, identification of recurrent disease, management of parathyroid and recurrent laryngeal nerves with neuromonitoring.

Thyroid Follicular Epithelial Cell-Derived Cancer: New Approaches and Treatment Strategies

Thyroid follicular epithelial cell-derived cancer includes papillary carcinoma, follicular carcinoma, Hürthle cell carcinoma, poorly differentiated thyroid cancer, and anaplastic thyroid carcinoma. Although the incidence of thyroid cancer has increased over the past 30 years, there has not been a significant increase in patient mortality. Use of increasingly sensitive detection methods such as high-resolution imaging has enabled earlier detection and better characterization of the thyroid malignancies. In the past several years, researchers have evaluated genetic mutations promoting thyroid carcinogenesis and oncogenesis. The identification of genetic mutations is important in understanding tumor initiation and progression. Additionally, these identified mutations may also serve as potential diagnostic or prognostic indicators and therapeutic molecular targets.

Clinicopathological Characteristics of Thyroid Cancer in a Saudi Academic Hospital

Background

The global incidence of thyroid cancer (TC) has increased significantly over the past decades. In Saudi Arabia, it is the third most common cancer among adults. This study aims to review the clinical and histopathological characteristics of TC in Saudi Arabia and analyze the size trend over the years.

Methods

We conducted a retrospective chart review of all differentiated and poorly differentiated TC patients following up at a tertiary care center in the Western region of Saudi Arabia. All patients 11 years and older, diagnosed between 2004 - 2018, and with sufficient histopathological data were included.

Follicular and poorly differentiated TC were categorized and tumor stage was allocated. We performed descriptive and size trend analysis.

Results

We had a total of 285 patients who qualified for inclusion. The mean age at diagnosis was 40.6 years, and 81.05% of patients were females. Papillary TC comprised 88.07% of these neoplasms, and most patients (89.12%) were at Stage I. Only papillary TC showed a gender difference in the age of the diagnosis. In men, the mean age at diagnosis of papillary TC was 46.98 ± 15.4 years, while in female patients, it was 39.02 ± 12.8 years (p-value = 0.0001).

We did not find a trend toward smaller tumours in the more recent years in comparison to the early years (r = -0.083, p-value = 0.168).

Conclusions

TC is diagnosed at a younger age and larger sizes in Saudi Arabia in comparison to other countries. A gender difference was only noted with papillary TC in regard to the age of diagnosis. There was no trend toward smaller sizes of TC over the years.

Poorly differentiated thyroid carcinoma (PDTC) characteristics and the efficacy of radioactive iodine (RAI) therapy as an adjuvant treatment in a tertiary cancer care center

BACKGROUND

Poorly differentiated thyroid cancer (PDTC) is biologically more aggressive. Surgery remains the mainstay of treatment. The utility of radioactive iodine (RAI) after surgery is unclear.

METHODS

In this retrospective study, patients treated between Jan 2012 and Dec 2017 were included. The demographic, clinical and treatment-related details, including RAI ablation, were recorded and their survival analyzed.

RESULTS

Thirty-five patients fulfilled the eligibility criteria. Majority was treatment naïve at presentation. All patients underwent surgery followed by RAI ablation, with a cumulative median dose of 220 mCi (range 40-1140). Sixteen patients received more than one radioiodine treatment for distant metastases. Incomplete resection, age > 45 years and the presence of distant metastasis influenced survival the most. The 3-year PFS of patients with PDTC was 69%.

CONCLUSION

All patients in our series showed uptake and responded to treatment. Further use of molecular markers and functional molecular imaging would better our understanding of this entity.

Histopathology and immunohistochemistry as prognostic factors for poorly differentiated thyroid cancer in a series of Polish patients

Background

Poorly differentiated thyroid cancer (PDTC) is a rare but aggressive type of thyroid cancer (TC) and the main cause of death from non-anaplastic follicular cell-derived TC. Although the Turin criteria are well defined, the pathological features that could serve as diagnostic and prognostic factors remain controversial.

Materials and methods

Forty-nine consecutive PDTC cases were identified in a single cancer center between 2000 and 2018. We analyzed the impact of routine histopathological and immunohistochemical features and several parameters that are not routinely included in pathology reports such as the presence of atypical mitoses, the amount of necrosis, or insulin-like growth factor-II mRNA-binding protein 3 immunostaining on the survival of patients with PDTC. Overall survival (OS) and disease-specific survival (DSS) were calculated using the Kaplan-Meier method.

Results

Of the 49 PDTC 34 (69.4%) showed the insular pattern of growth. The median of poorly differentiated area was 95% (range, 1–100), and 30 (61.2%) patients had a predominant (>50%) insular area. The 5-year OS and DSS rates at a median follow-up of 57 months were 60.6% and 64.3%, respectively. Univariate analysis showed that tumor size >4 cm, presence of atypical mitoses, Ki-67 >5%, and thyroglobulin (Tg)-negative immunostaining were associated with a higher risk of PDTC-related death. Atypical mitoses and Tg negativity were independent factors of worse DSS in multivariate analysis. Patients with insular and predominant insular areas showed a 3- and 6-fold higher risk of PDTC death when they displayed atypical mitoses.

Conclusions

In PDTC, the presence of atypical mitoses may be helpful in identifying patients with poorer outcome and worth including in pathology reports, particularly in tumors with a dominant insular pattern of growth. Additionally, the inclusion of Tg immunostaining may be considered in a prognostic context, and not only as a diagnostic feature.

Poorly differentiated thyroid cancer in the context of the revised 2015 American Thyroid Association Guidelines and the Updated American Joint Committee on Cancer/Tumor-Node-Metastasis Staging System (eighth edition)

OBJECTIVE

Poorly differentiated thyroid cancer (PDTC) is a rare, but aggressive thyroid cancer (TC) and a main cause of death from non-anaplastic follicular cell-derived TC. Assessing the risk of PDTC-related death and the risk of recurrence is important for clinicians. The recent American Thyroid Association (ATA) 2015 guidelines and the updated 8th edition of the American Joint Committee on Cancer/Tumor-Node-Metastasis (AJCC/TNM) staging system should support clinicians in the management approach to PDTC patients.

PATIENTS

Forty-six consecutive PDTC patients treated in a single oncologic centre, 2000-2017.

MEASUREMENTS

Retrospective analysis of TNM stage, initial risk, response-to-therapy categories, follow-up and final disease status incorporating the ATA 2015 criteria and the 8th AJCC/TNM staging system. Disease-specific survival (DSS) using the Kaplan-Meier method.

RESULTS

Of the 46 PDTC 21 (45.6%) were ATA high risk (HR), 22 (47.8%), 17 (37%) and seven (15.2%) were TNM stages I, II, and III-IV, respectively. During a median follow-up of 55.5 months, two (4.3%) patients were recurrent, 18 (39.1%) died of PDTC. The 5-/10-year DSS were 65/57%, respectively. According to the AJCC/TNM, the 5-/10-year DSS of I, II, and III-IV stage were 83/83%; 77/55%, and 0/0%, respectively. According to the 2015 ATA initial risk, the 5-/10-year DSS were 91/72% for ATA intermediate risk and 38/38% for ATA HR patients.

CONCLUSIONS

In PDTC patients, the updated AJCC/TNM staging system accurately predicts a high risk of death in stage III-IV, whereas it seems to be inadequate for predicting a very low or low risk of death expected for differentiated TC in stage I-II. The ATA initial HR may be also used to predict a high risk of PDTC-related death.

Anti-cancer Effects of HNHA and Lenvatinib by the Suppression of EMT-Mediated Drug Resistance in Cancer Stem Cells

Anaplastic thyroid cancer (ATC) constitutes less than 2% of total thyroid cancers but accounts for 20–40% of thyroid cancer-related deaths. Cancer stem cell drug resistance represents a primary factor hindering treatment. This study aimed to develop targeted agents against thyroid malignancy, focusing on individual and synergistic effects of HNHA (histone deacetylase), lenvatinib (FGFR), and sorafenib (tyrosine kinase) inhibitors. Patients with biochemically and histologically proven papillary thyroid cancer (PTC) and ATC were included. Cell samples were obtained from patients at the Thyroid Cancer Center, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul, Korea. PTC and ATC cells were treated with lenvatinib or sorafenib, alone or in combination with HNHA. Tumor-bearing mice (10/group) were administered 10 mg/kg lenvatinib (p.o.) or 40 mg/kg sorafenib (p.o.), alone or in combination with 25 mg/kg HNHA (i.p.) once every three days. Gene expression in patient-derived PTC and ATC cells was compared using a microarray approach. Cellular apoptosis and proliferation were examined by immunohistochemistry and MTT assays. Tumor volume and cell properties were examined in the mouse xenograft model. HNHA-lenvatinib combined treatment induced markers of cell cycle arrest and apoptosis and suppressed anti-apoptosis markers, epithelial-mesenchymal transition (EMT), and the FGFR signaling pathway. Combined treatment induced significant tumor shrinkage in the xenograft model. HNHA-lenvatinib combination treatment thus blocked the FGFR signaling pathway, which is important for EMT. Treatment with HNHA-lenvatinib combination was more effective than either agent alone or sorafenib-HNHA combination. These findings have implications for ATC treatment by preventing drug resistance in cancer stem cells.

Application of intensity-modulated radiotherapy in unresectable poorly differentiated thyroid carcinoma

Poorly differentiated thyroid carcinoma (PDTC) is a rare and aggressive malignancy with high rates of invasion and distant metastasis. This study was to explore the ability of intensity-modulated radiotherapy (IMRT) combined with chemotherapy to manage unresectable PDTC. Between February 2011 and April 2012, 5 patients with unresectable PDTC were treated by IMRT at our institution and were included in this analysis. The median radiotherapy dose to the gross tumor volume (GTV) was 66 Gy/33 fractions/6.4 weeks. All patients received chemotherapy, and one patient with tumor compression symptoms had a tracheotomy before treatment. The mean survival time of the 5 patients was 41.6 months. The direct causes of death were distant metastases (40%) and progression of the locoregional disease (20%). In conclusion, IMRT combined with chemotherapy for unresectable PDTC might be beneficial to improve locoregional control. Further new therapies are needed to control metastases.

Poorly Differentiated Thyroid Carcinoma: 10-Year Experience in a Southeast Asian Population

BACKGROUND

No previous studies have been published on poorly differentiated thyroid carcinoma (PDTC) in Southeast Asia.

METHODS

We included all adult PDTC patients diagnosed using the Turin criteria at the Philippine General Hospital from 2006 to 2015. The data collected included demographics, clinical presentation, histopathology, treatment, and outcomes. Tests of association were employed to compare these data with foreign studies on PDTC, as well as with local studies on well differentiated thyroid carcinoma (WDTC) and anaplastic thyroid carcinoma (ATC).

RESULTS

Eighteen PDTC cases were identified. The median age was 62 years old, with the majority being females. All patients had goiter on presentation, and most were stage IV at the time of diagnosis. In terms of PDTC subtype, insular and trabecular patterns were equally common. Extrathyroidal extension was documented in eight patients, while five patients each had nodal and distant metastasis. All but one patient underwent surgery; however, less than half received adjuvant radioiodine therapy. The 5-year survival rate was 83%. Three patients (16.7%) died at a median of 12 months after diagnosis. Nine (50%) are still alive with persistent and/or recurrent disease at a median of 39 months after diagnosis.

CONCLUSION

The behavior of PDTC in this Southeast Asian population was found to be similar to patterns observed in other regions, and exhibited intermediate features between WDTC and ATC. Appropriate surgery provided excellent 5-year survival rates, but the role of adjuvant therapy remains unclear. Larger studies are needed to identify prognostic factors in this population.