Cervical soft tissue recurrence of differentiated thyroid carcinoma after thyroidectomy indicates a poor prognosis

Salvage surgery for cervical radioiodine refractory 18F-FDG-PET positive recurrence of papillary thyroid cancer

PURPOSE

Five percent of patients with differentiated thyroid cancer are diagnosed with radioiodine refractory relapse in the course of the disease. For isolated or oligometastatic cervical recurrence, resection or another local treatment is recommended. In this study, the impact of surgical treatment of cervical radioiodine refractory 18F-FDG-PET positive relapse of papillary thyroid cancer (PTC) was evaluated.

METHODS

Patients receiving radioiodine therapy between 2005 and 2015 at the University Hospital of Cologne, Germany, for PTC were screened. The subgroup of patients undergoing surgery during the course of disease after recommendation by a multidisciplinary endocrine team for cervical radioiodine refractory 18F-FDG-PET positive recurrence was identified. Demographics, clinic-pathologic characteristics, oncologic treatment, and outcome were analyzed.

RESULTS

Thirty (3%) of 969 patients with PTC treated with radioiodine therapy at our institution underwent surgery for radioiodine refractory 18F-FDG-PET positive cervical recurrence during the course of the disease. In eight (26.6%) patients, more than one operation was performed. Sixteen (53%) patients received external beam radiation therapy (EBRT) after surgery. Follow-up was on average, 79.2 ± 61.6 months after the last surgical treatment. Biochemical and radiological cure was seen in 12 (40%) patients. Remission was significantly more frequent in younger patients (P = 0.0001) with lymph node rather than soft tissue tumor recurrence (P = 0.004).

CONCLUSIONS

Surgical treatment of radioiodine refractory 18F-FDG-PET positive cervical recurrence led to biochemical and radiological cure in about 40% of patients in this study. Further data are needed concerning risk stratification of potential subgroups benefitting of surgical approach and the possible role of EBRT after repetitive surgery.

Emerging roles of circUBAP2 targeting miR-370-3p in proliferation, apoptosis, and invasion of papillary thyroid cancer cells

Circular RNAs (circRNAs) have been documented to be aberrantly expressed in many types of malignancies and involved in cancer progression. However, their role in thyroid cancer (TC) remains largely unknown. Our study aimed to explore the role and mechanism of circUBAP2 in TC. The differentially expressed circRNAs in TC tissues were identified using GSE18105 from gene expression omnibus (GEO) database. CircUBAP2 and miR-370-3p expression was analyzed using qRT-PCR. The stability of circUBAP2 was confirmed by actinomycin D and RNase R. The subcellular localization of circUBAP2 was detected using cell fractionation assay. Cell proliferation, apoptosis, and invasion were evaluated using MTT, flow cytometry analysis, and Transwell invasion assay, respectively. The interaction between circUBAP2 and miR-370-3p was predicted using bioinformatics analysis and validated by luciferase reporter assay, RNA pull-down assay, and RNA immunoprecipitation. CircUBAP2 was upregulated and miR-370-3p was downregulated in TC tissues and cells. CircUBAP2 was highly stable, resistant to RNase R digestion, and predominantly localized in the cytoplasm. CircUBAP2 knockdown inhibited cell proliferation and invasion and triggered apoptosis in TC cells. Bioinformatics analysis showed that circUBAP2 contained putative binding sites of miR-370-3p. CircUBAP2 acted as a sponge to inhibit miR-370-3p expression. Mechanistically, miR-370-3p inhibition abolished the effects of circUBAP2 on proliferation, apoptosis, and invasion in TC cells. Taken together, CircUBAP2 knockdown impeded the proliferation and invasion and induced apoptosis in TC cells via sponging miR-370-3p.

Head-to-Head Comparison of Neck 18F-FDG PET/MR and PET/CT in the Diagnosis of Differentiated Thyroid Carcinoma Patients after Comprehensive Treatment

Simple Summary

The most advanced positron emission tomography–magnetic resonance (PET/MR) combines the high soft tissue contrast of MRI with the high functional/metabolic sensitivity of PET and has the potential to achieve the highest level of diagnostic performance for refractory malignancies in differentiated thyroid cancer (DTC) patients. The utility of PET/MR in the postoperative follow-up of DTC patients has been relatively ambiguous. This retrospective study compared ¹⁸F-fluorodeoxyglucose neck PET/MR with PET/CT head-to-head, in order to evaluate the diagnostic efficacy of PET/MR in assessment malignancy in DTC patients after comprehensive treatment. We determined that PET/MR presented better detection rates, image conspicuity, and sensitivity than PET/CT in recurrent DTC lesions and cervical lymph node metastases. The addition of neck PET/MR scan after whole-body PET/CT may provide more favorable diagnostic information.

Abstract

We explored the clinical value of ¹⁸F-FDG PET/MR in a head-to-head comparison with PET/CT in loco-regional recurrent and metastatic cervical lymph nodes of differentiated thyroid carcinoma (DTC) patients after comprehensive treatment. ¹⁸F-FDG PET/CT and neck PET/MR scans that were performed in DTC patients with suspected recurrence or cervical lymph node metastasis after comprehensive treatment were retrospectively analyzed. Detection rates, diagnostic efficacy, image conspicuity, and measured parameters were compared between ¹⁸F-FDG PET/CT and PET/MR. The gold standard was histopathological diagnosis or clinical and imaging follow-up results for more than 6 months. Among the 37 patients enrolled, no suspicious signs of tumor were found in 10 patients, 24 patients had lymph node metastasis, and 3 patients had both recurrence and lymph node metastases. A total of 130 lesions were analyzed, including 3 malignant and 6 benign thyroid nodules, as well as 74 malignant and 47 benign cervical lymph nodes. Compared with PET/CT, PET/MR presented better detection rates (91.5% vs. 80.8%), image conspicuity (2.74 ± 0.60 vs. 1.9 ± 0.50, p < 0.001, especially in complex level II), and sensitivity (80.5% vs. 61.0%). SUVmax differed in benign and malignant lymph nodes in both imaging modalities (p < 0.05). For the same lesion, the SUVmax, SUVmean, and diameters measured by PET/MR and PET/CT were consistent and had significant correlation. In conclusion, compared with ¹⁸F-FDG PET/CT, PET/MR was more accurate in determining recurrent and metastatic lesions, both from a patient-based and from a lesion-based perspective. Adding local PET/MR after whole-body PET/CT may be recommended to provide more precise diagnostic information and scope of surgical resection without additional ionizing radiation. Further scaling-up prospective studies and economic benefit analysis are expected.

Recurrence of thyroid carcinoma in cervical soft tissue following surgical implantation: Case report

INTRODUCTION

Thyroid cancer is the most common type of malignant endocrine cancer. Differentiated thyroid cancer, which includes papillary and follicular cancers, represents majority (90%) of all thyroid cancers and has a favorable prognosis. However, a minority of patients develops loco-regional recurrence.

CASE REPORT

We report here a rare case of a 63 years-old man who underwent total thyroidectomy in 2015 for multinodular goiter whose histopathological examination revealed a papillary thyroid carcinoma. He received 6 weeks later a 100 mCi of radioactive iodine therapy. In 2017, he was admitted for multiple cervical lymph nodes with high serum thyroglobulin level (234 ng/mL) which required a bilateral central and lateral neck dissection. He was readmitted in 2019 for multiple subcutaneous neck nodules with high serum thyroglobulin level (197 ng/mL). The histopathological examination of the excised nodules revealed a papillary thyroid carcinoma. The patient showed no sign of recurrence after 2 years follow-up.

CONCLUSION

Local soft tissue recurrence followed surgical implantation should be suspected when nodules are determined alongside the thyroid after previous thyroid surgery. Therapy for these soft tissue implants may be difficult; a comprehensive long-term postoperative evaluation should be completed to minimize the risk of recurrence in cervical soft tissue.

Ultrasound characteristics of cervical lesions in patients with radioiodine refractory differentiated thyroid cancer: A strobe-compliant article

Radioiodine refractory (RAIR) is the major cause of thyroid cancer-related death. In order to avoid needless Radioiodine (RAI) therapy, recognizing the RAIR cases in time is important for the patients to obtain more time for the effective therapy.Evaluate the ultrasound features of cervical metastatic lymph node in patients with RAIR differentiated thyroid cancer (DTC).Seventeen adult patients with histologically confirmed locally advanced or metastatic RAIR-DTC were prospectively enrolled. The ultrasound (US) characteristics of cervical lesions in patients with the RAIR-DTC were compared with cervical lymph node metastasis from 59 non RAIR-DTC cases.Among the 17 patients, cervical lymph node metastasis was found in 15 patients (88.3%). The cervical lesions of RAIR-DTC (mean size, 2.0 cm) were larger than that in non RAIR-DTC group (mean size, 1.30 cm). More multiple lesions and more lesions with visible flow were found in the RAIR Group, while fewer hyperechogenic punctuations were found in RAIR group (P < .05). The distant metastasis rates showed that RAIR-DTC led to a poorer prognosis than those of patients in the non RAIR Group (P < .01).Ultrasound can help distinguish metastasized cervical lymph nodes of RAIR-DTC patients from non RAIR-DTC patients. For RAIR-DTC patients, a long-term US evaluation should be performed.

Long noncoding RNA RP11-547D24.1 regulates proliferation and migration in papillary thyroid carcinoma: Identification and validation of a novel long noncoding RNA through integrated analysis of TCGA database

Long noncoding RNAs (lncRNAs) are known to be key regulators of numerous biological processes, and substantial evidence supports that abnormal lncRNA expression plays a significant role in tumorigenesis and tumor progression. However, the mechanism by which lncRNAs function in thyroid carcinoma are still unclear. To investigate the role of lncRNAs in the tumorigenesis of papillary thyroid carcinoma (PTC), we analyzed lncRNA data in The Cancer Genome Atlas RNA‐Seq database. A comparison of lncRNAs in cancerous thyroid tissues and normal tissues revealed hundreds of differentially expressed lncRNAs. Of 7589 lncRNAs identified in 561 thyroid cancer cases (503 cancerous tissues and 58 normal tissues), the expression levels of 144 were found to be aberrant (|log2 fold change| >2 and adjusted P < 0.05). The top 10 lncRNAs with the most significant differences were LINC01977, RP11‐363E7.4, RP3‐483K16.4, RP11‐547D24.1, RUNDC3A‐AS1, AC093609.1, CTD‐2008L17.2, HAGLROS, UNC5B‐AS1, and LINC01354. In addition, CTD‐2008L17.2, HAGLROS, AC093609.1, UNC5B‐AS1, and RUNDC3A‐AS1 were shown to play vital roles in determining the histological cancer type. Furthermore, RP11‐547D24.1 and UNC5B‐AS1 could distinguish patients with different stages of PTC. The lncRNA RP11‐547D24.1 was validated by loss‐of‐function assays, revealing that downregulation of this lncRNA regulates thyroid tumor cell proliferation and apoptosis, invasion, and migration. This study demonstrates the potential for using lncRNAs to interpret the pathogenesis and development of PTC.