Clinicopathological features and outcomes after radioactive iodine treatment of oncocytic well-differentiated thyroid carcinomas

Radioactive Iodine Therapy Does not Improve Cancer-specific Survival in Hürthle Cell Carcinoma of the Thyroid

CONTEXT

It is unclear whether radioactive iodine (RAI) therapy could improve cancer-specific survival (CSS) in patients with Hürthle cell carcinoma (HCC) of the thyroid.

OBJECTIVE

To investigate the effect of RAI on CSS in HCC patients.

METHODS

HCC patients who underwent total thyroidectomy (TT) were identified from the Surveillance, Epidemiology, and End Results (SEER) database between 2000 and 2018. The Kaplan-Meier method and the Cox proportional hazards regression model were used to evaluate CSS. Propensity score-matched (PSM) analyses were performed to control the influence of potential confounders.

RESULTS

A total of 2279 patients were identified. RAI treatment was not significantly associated with improved CSS in overall or PSM cohort. Subgroup analyses indicated similar results, even in patients with aggressive features such as age 55 years or older, tumor size greater than 40 mm, distant disease in SEER staging, extrathyroidal extension, and lymph node metastases (all P > .05).

CONCLUSION

RAI has no statistically significant influence on the CSS in HCC patients. This information may aid in decision-making for RAI therapy in these patients.

Hürthle Cell Carcinoma of the Thyroid Gland: Systematic Review and Meta-analysis

INTRODUCTION

Hürthle cell carcinoma (HCC) comprises about 5% of thyroid carcinoma cases. Partly because of its rarity there is much we still need to know about HCC as compared to other histological cancer subtypes.

METHODS

We conducted a systematic literature review following PRISMA guidelines and meta-analysis, from 2000 to 2020, to investigate the main characteristics of HCC and clarify information concerning tumor behavior and treatment.

RESULTS

Our review included data from 9638 patients reported in 27 articles over the past 20 years. This tumor occurred more frequently in women (67.5%). The mean age was 57.6 years, and the mean size of the neoplasm at diagnosis was 30 mm. Extrathyroidal extension was common (24%) but lymph node metastasis was not (9%). Total thyroidectomy was the most common surgical approach, with neck dissection usually performed in cases with clinically apparent positive neck nodes. Radioiodine therapy was frequently applied (54%), although there is no consensus about its benefits. The mean 5- and 10-year overall survival was 91% and 76%, respectively.

CONCLUSION

This review serves to further elucidate the main characteristics of this malignancy. HCC of the thyroid is rare and most often presents with a relatively large nodule, whereas lymph node metastases are rare. Given the rarity of HCC, a consensus on their treatment is needed, as doubts remain concerning the role of specific tumor findings and their influence on management.

Genetics, Diagnosis, and Management of Hürthle Cell Thyroid Neoplasms

Hürthle cell lesions have been a diagnostic conundrum in pathology since they were first recognized over a century ago. Controversy as to the name of the cell, the origin of the cell, and even which cells in particular may be designated as such still challenge pathologists and confound those treating patients with a diagnosis of "Hürthle cell" anything within the diagnosis, especially if that anything is a sizable mass lesion. The diagnosis of Hürthle cell adenoma (HCA) or Hürthle cell carcinoma (HCC) has typically relied on a judgement call by pathologists as to the presence or absence of capsular and/or vascular invasion of the adjacent thyroid parenchyma, easy to note in widely invasive disease and a somewhat subjective diagnosis for minimally invasive or borderline invasive disease. Diagnostic specificity, which has incorporated a sharp increase in molecular genetic studies of thyroid tumor subtypes and the integration of molecular testing into preoperative management protocols, continues to be challenged by Hürthle cell neoplasia. Here, we provide the improving yet still murky state of what is known about Hürthle cell tumor genetics, clinical management, and based upon what we are learning about the genetics of other thyroid tumors, how to manage expectations, by pathologists, clinicians, and patients, for more actionable, precise classifications of Hürthle cell tumors of the thyroid.

Oncocytic Papillary Thyroid Carcinoma and Oncocytic Poorly Differentiated Thyroid Carcinoma: Clinical Features, Uptake, and Response to Radioactive Iodine Therapy, and Outcome

OBJECTIVE

The main objective of this study was to review the clinicopathologic characteristics and outcome of patients with oncocytic papillary thyroid carcinoma (PTC) and oncocytic poorly differentiated thyroid carcinoma (PDTC). The secondary objective was to evaluate the prevalence and outcomes of RAI use in this population.

METHODS

Patients with oncocytic PTC and PDTC who were treated at a quaternary cancer centre between 2002 and 2017 were retrospectively identified from an institutional database. All patients had an expert pathology review to ensure consistent reporting and definition. The cumulative incidence function was used to analyse locoregional failure (LRF) and distant metastasis (DM) rates. Univariable analysis (UVA) was used to assess clinical predictors of outcome.

RESULTS

In total, 263 patients were included (PTC [n=218], PDTC [n=45]) with a median follow up of 4.4 years (range: 0 = 26.7 years). Patients with oncocytic PTC had a 5/10-year incidence of LRF and DM, respectively, of 2.7%/5.6% and 3.4%/4.5%. On UVA, there was an increased risk of DM in PTC tumors with widely invasive growth (HR 17.1; p<0.001), extra-thyroidal extension (HR 24.95; p<0.001), angioinvasion (HR 32.58; p=0.002), focal dedifferentiation (HR 19.57, p<0.001), and focal hobnail cell change (HR 8.67, p=0.042). There was additionally an increased risk of DM seen in male PTC patients (HR 5.5, p=0.03).The use of RAI was more common in patients with larger tumors, angioinvasion, and widely invasive disease. RAI was also used in the management of DM and 43% of patients with oncocytic PTC had RAI-avid metastatic disease. Patients with oncocytic PDTC had a higher rate of 5/10-year incidence of LRF and DM (21.4%/45.4%; 11.4%/40.4%, respectively). Patients with extra-thyroidal extension had an increased risk of DM (HR 5.52, p=0.023) as did those with angioinvasion. Of the patients with oncocytic PDTC who received RAI for the treatment of DM, 40% had RAI-avid disease.

CONCLUSION

We present a large homogenous cohort of patients with oncocytic PTC and PDTC, with consistent pathologic reporting and definition. Patients with oncocytic PTC have excellent clinical outcomes and similar risk factors for recurrence as their non-oncocytic counterparts (angioinvasion, large tumor size, extra-thyroidal extension, and focal dedifferentiation). Compared with oncocytic PTCs, the adverse biology of oncocytic PDTCs is supported with increased frequency of DM and lower uptake of RAI.

Vitamin D receptor knockdown attenuates the antiproliferative, pro‑apoptotic and anti‑invasive effect of vitamin D by activating the Wnt/β‑catenin signaling pathway in papillary thyroid cancer

Vitamin D and the vitamin D receptor (VDR) complex have been reported to inhibit the growth of several types of tumor; however, their function in papillary thyroid cancer (PCT) remains unknown. In addition, the Wnt/β-catenin signaling pathway was discovered to serve a critical role in the pathology of PCT. Therefore, the present study aimed to determine the role of the VDR and its association with Wnt/β-catenin signaling in vitamin D-treated PTC cells. VDR expression was detected in human PTC cells (including MDA-T120, MDA-T85, SNU-790 and IHH4 cells) and thyroid follicular cells (Nthy-ori 3–1 cells). SNU-790 and IHH4 cells were infected with KD-VDR or negative control (KD-NC) lentiviruses, treated with 1,25(OH)₂D3 (the active form of vitamin D), and subsequently referred to as the KD-VDR&vitD and KD-NC&vitD groups, respectively. Additionally, PTC cells infected with KD-NC and not treated with 1,25(OH)₂D3 were used as the normal control and referred to as the KD-NC group. VDR mRNA and protein expression levels were increased in MDA-T120, SNU-790 and MDA-T85 cells compared to Nthy-ori 3-1 cells, whereas in IHH4 cells, VDR mRNA and protein expression levels were similar to Nthy-ori 3-1 cells. In SNU-790 and IHH4 cells, cell proliferation and invasion were decreased in the KD-NC&vitD group compared with the KD-NC group, but increased in the KD-VDR&vitD group compared with the KD-NC&vitD group. Cell apoptosis was increased in the KD-NC&vitD group compared with the KD-NC group, and decreased in the KD-VDR&vitD group compared with the KD-NC&vitD group. Furthermore, the expression levels of Wnt family member 3 and catenin β1 were decreased in the KD-NC&vitD group compared with the KD-NC group, but increased in the KD-VDR&vitD group compared with the KD-NC&vitD group. In conclusion, the present study revealed that VDR-KD attenuated the antiproliferative, pro-apoptotic and anti-invasive effects of vitamin D in PTC by activating the Wnt/β-catenin signaling pathway.