Management of recurrent cervical papillary thyroid cancer

Bitter Taste Receptor Agonists Induce Apoptosis in Papillary Thyroid Cancer

Background

Papillary thyroid carcinoma (PTC) is the most common thyroid malignancy, with a 20% recurrence rate. Bitter taste receptors (T2Rs) and their genes ( TAS2Rs ) may regulate survival in solid tumors. This study examined T2R expression and function in PTC cells.

Methods

Three PTC cell lines (MDA-T32, MDA-T68, MDA-T85) were analyzed for expression using RT-qPCR and immunofluorescence. Live cell imaging measured calcium responses to six bitter agonists. Viability and apoptosis effects were assessed using crystal violet and caspase 3/7 activation assays. Genome analysis of survival was conducted.

Results

TAS2R14 was consistently highly expressed in all cell lines. Five bitter agonists produced significant calcium responses across all cell lines. All bitter agonists significantly decreased viability and induced apoptosis. Higher TAS2R14 expression correlated with better progression-free survival in patients (p<0.05).

Conclusions

T2R activation by bitter agonists induces apoptosis and higher TAS2R expression is associated with survival, suggesting potential therapeutic relevance in thyroid cancer management.

Ethanol ablation of papillary thyroid carcinoma nodal metastases: Long-term outcomes

BACKGROUND

Percutaneous ethanol ablation has emerged as a treatment for recurrent papillary thyroid carcinoma in the lateral neck after compartment-oriented therapeutic lymphadenectomy. However, the safety and utility of percutaneous ethanol ablation as a primary treatment modality for lateral neck metastases remains undefined. We aimed to investigate long-term outcomes of percutaneous ethanol ablation of lateral neck papillary thyroid carcinoma recurrence both with and without prior lymphadenectomy.

METHODS

We conducted a retrospective study of patients with lateral neck papillary thyroid carcinoma treated with percutaneous ethanol ablation from 2013 to 2018. Patient characteristics, disease volume, morbidity, and recurrence (development of new lymphadenopathy within a percutaneous ethanol ablation-treated nodal compartment) were assessed.

RESULTS

We identified 117 patients who underwent percutaneous ethanol ablation for papillary thyroid carcinoma lateral neck metastases-67 (57%) had a prior lateral neck dissection. Median follow-up after percutaneous ethanol ablation was 5.5 years (interquartile range 3.1-7.5). On average, 1.4 lymph nodes (range: 1-6) were treated. Three patients (3%) developed transient nerve-related complications after percutaneous ethanol ablation. Of 15 patients who underwent lateral neck dissection after percutaneous ethanol ablation (including patients undergoing repeat lateral neck dissection), dissection was "difficult" in 8 (53%) (7 of whom had previously undergone lateral neck dissection), and 4 (27%) developed complications (transient nerve dysfunction = 3, lymphatic leak = 1). Thirty-three patients (28%) developed recurrent papillary thyroid carcinoma. No difference in recurrence was seen between patients who did or did not undergo pre-percutaneous ethanol ablation lateral neck dissection (no pre-percutaneous ethanol ablation lateral neck dissection: 24%, pre-percutaneous ethanol ablation lateral neck dissection, 31%; hazard ratio = 1.27, 95% confidence interval 0.62-2.58; P = .514).

CONCLUSION

Percutaneous ethanol ablation may be a safe primary treatment modality for papillary thyroid carcinoma lateral neck nodal recurrence in selected patients with low-volume nodal disease.

Clinical Significance of the Lymph Node Ratio of the Second Operation to Predict Re-Recurrence in Thyroid Carcinoma

The purpose of this study was to establish the risk factors for re-recurrences and disease-specific mortality (DSM) in recurrent thyroid cancer. Patients with recurrent thyroid cancer who underwent initial thyroid surgery from January 2000 to December 2019 at Seoul St. Mary's Hospital (Seoul, Korea) were assessed. Clinicopathological characteristics and long-term oncologic outcomes were compared between patients with one recurrence (n = 202) and patients with re-recurrences (n = 44). Logistic regression and cox-regression analyses were conducted to determine the risk factors for re-recurrences and DSM, respectively. Receiver-operating characteristic curve analysis was performed to determine the cutoff value for lymph node ratio (LNR) as a predictor of re-recurrences. DSM was significantly higher in the re-recurrence group compared with the single-recurrence group (6.8% vs. 0.5%, p = 0.019). Surgical treatment at the first recurrence significantly lowered the risk of re-recurrences. Age (≥55), male sex, and LNR (≥0.15) were independent significant risk factors for re-recurrences in patients who underwent surgery at the first recurrence. Surgical resection is the optimal treatment for initial thyroid cancer recurrence. LNR at re-operation is more effective in predicting re-recurrence than the absolute number of metastatic LNs.

Minimal residual disease assessment of papillary thyroid carcinoma through circulating tumor cell-based cytology

The overall estimated risk of recurrence after an apparently complete thyroid cancer resection ranges from <1% to 55%, and the high-quality pathology report is crucial for proper risk stratification. The neck ultrasound (US) and serum thyroglobulin (Tg) and anti-Tg antibody (TgAb) assays are the mainstays for Differentiated Thyroid Cancer (DTC) follow-up. However, the neck US includes a high frequency of nonspecific findings and despite the serum, Tg unmasks the presence of thyrocytes, it is not discriminating between normal and malignant cells. In this study, to improve post-surgery follow-up of minimal residual disease in papillary thyroid cancer (PTC) patients, blood-derived cytology specimens were evaluated for the presence of circulating tumor cells (CTCs). The presence of CTCs of thyroid origin was confirmed by cytomorphological and tissue-specific antigens analysis (Thyroid Transcription Factor-1/TTF-1 and Tg) and proliferative profile (percentage of cells in S-phase). Our data revealed an unfavorable' prognostic risk in patients with >5% CTCs (p = 0.09) and with >30% S-phase cells at baseline (p = 0.0015), predicting ≤1 year relapsing lesion event. These results suggest a new intriguing frontier of precision oncology forefront cytology-based liquid biopsy.

Taraxasterol inhibits TGF-β1-induced epithelial-to-mesenchymal transition in papillary thyroid cancer cells through regulating the Wnt/β-catenin signaling

Taraxasterol (TAR) is a kind of active compound extracted from dandelion and its molecular structure resembles steroid hormones. Recently, TAR has been reported to show an anti-tumor activity. However, the specific role of TAR in papillary thyroid cancer (PTC) has not been clarified. In this study, we investigated the effect of TAR on PTC cell migration, invasion and epithelial-to-mesenchymal transition (EMT) induced by TGF-β1. PTC cells were exposed to TGF-β1 (5 ng/mL) and then treated with different concentrations of TAR. We found that TAR showed no obvious cytotoxicity below 10 μg/mL but notably reduced migration and invasion of TGF-β1-treated PTC cells. Moreover, TAR treatment decreased MMP-2 and MMP-9 levels, and obviously affected the expression of EMT markers. We also observed that Wnt3a and β-catenin levels were significantly increased in TGF-β1-treated PTC cells while TAR inhibited these effects in a concentration-dependent manner. Additionally, activation of the Wnt pathway by LiCl attenuated the suppressive effect of TAR on TGF-β1-induced migration, invasion and EMT in PTC cells. Taken together, we highlighted that TAR could significantly suppress TGF-β1-regulated migration and invasion by reversing the EMT process via the Wnt/β-catenin pathway, suggesting that TAR may be a potential anti-cancer agent for PTC treatment.

Localización intraoperatoria de las recurrencias en cáncer de tiroides mediante la inyección de azul de metileno guiada por ecografía

Introducción. La cirugía para extirpación de metástasis en un cuello previamente intervenido afronta un reto para lograr una resección exitosa. El presente estudio pretende demostrar la utilidad de la técnica de inyección de azul de metileno, guiada por ecografía, para la localización intraoperatoria de lesiones recurrentes en cáncer de tiroides, para facilitar su resección. Métodos. Se realizó un estudio observacional, descriptivo y retrospectivo, en pacientes reintervenidos por recurrencia de carcinoma diferenciado de tiroides, durante un periodo de dos años y medio. Se utilizó la inyección intratumoral de azul de metileno guiada por ecografía para su identificación intraoperatoria de recurrencia. Se hizo análisis de variables demográficas y clínicas. Resultados. Este estudio incluyó 10 procedimientos en 9 pacientes, 77,8 % mujeres, con una media de edad de 54 años. Todos tenían un nivel de tiroglobulina detectable y elevado antes de la intervención; posteriormente, el 89 % presentó un descenso y el 33 % una adecuada respuesta bioquímica. La técnica agregó 10 minutos al tiempo quirúrgico. En el 100 % se identificaron de manera intraoperatoria los ganglios marcados; el promedio de ganglios resecados fue de 12, de los cuales, 6 fueron positivos, todos con carcinoma papilar de tiroides. Esta técnica se consideró de gran utilidad y de bajo costo en todos los casos. Discusión. Esta técnica se muestra como una estrategia efectiva para la identificación intraoperatoria de las recurrencias locorregionales en carcinoma de tiroides, permitiendo una disección ganglionar exitosa, disminuyendo complicaciones, tiempo quirúrgico y, especialmente, costos frente a otras intervenciones

Prevalence and characteristics of vagus nerve variations on neck ultrasonography

Purpose

We aimed to evaluate the true prevalence and characteristics of vagus nerve (VN) variations using the carotid artery (CA) and the internal jugular vein (C-I axis).

Methods

We examined patients who underwent neck ultrasonography (US) conducted by a single operator. A VN variation was defined as a VN located anterior or medial to the C-I axis. The subtypes of VN variation were classified as anterolateral, anteromiddle, anteromedial, and medial based on the relative location of the VN to the CA. The primary outcome parameters were the prevalence of VN variations and differences according to side, age, and sex.

Results

Out of 536 patients, right and left VN variations were identified in 20 (3.7%) and 186 (34.7%), respectively (P<0.001). The anteromiddle type was the commonest type observed on both sides. Eight right (1.5%) and 50 left VNs (9.3%) were located <2 mm from the lateral border of the ipsilateral thyroid gland (P<0.001). The prevalence of VN variations in male and female patients was 42.1% and 32.7%, respectively (P=0.029), and that in patients aged <20, 20-39, 40-59, and ≥60 years was 23.8%, 22.5%, 34.4%, and 47.4%, respectively (P<0.001).

Conclusion

Variations in the VN position were relatively common on US. The variations primarily involved the left VN in the lower cervical region, and an increasing prevalence with age was observed.

Evaluating the risk of re-recurrence in patients with persistent/recurrent thyroid carcinoma after initial reoperation

BACKGROUND

Although the 2015 American Thyroid Association guidelines proposed initial and response-to-therapy risk stratifications were adequately validated in untreated papillary thyroid cancer patients, it is still unknown how they work in persistent/recurrent papillary thyroid cancer patients. This study aimed to evaluate and revise the stratifications in these patients.

METHODS

This retrospective study included patients who received the first reoperation with complete thyroid resection but without radioactive iodine ablation. Stratifications were performed considering the persistent/recurrent tumor characteristics and thyroglobulin levels 1 to 6 months after reoperation and then revised with new prognostic factors and adjusted thyroglobulin cutoff values, respectively. Prognostic performance was evaluated with Kaplan-Meier curves, proportion of variation explained, and Harrell's concordance index.

RESULTS

Among a total of 232 patients, 5-year re-recurrence free survival rates were 92.4%, 86.2%, and 74.5% in low-, intermediate-, and high-risk patients, respectively (all P > .05) and 97.0%, 96.3%, and 81.6% in excellent response, intermediate response, and biochemical incomplete response groups, respectively (excellent response versus intermediate response, P > .05; intermediate response versus biochemical incomplete response, P < .05). After incorporating age at reoperation, recurrent primary size, and recurrent lymph node number, the high-risk group had significantly compromised re-recurrence free survival versus the intermediate-risk group (76.2% vs 91.6%). After adjusting thyroglobulin values, 5-year re-recurrence free survival rates were 96.4%, 85.9%, and 75.8% in excellent response (<1 ng/mL), intermediate response (1-10 ng/mL), and biochemical incomplete response (≥10 ng/mL) groups, respectively (all P < .05), with a higher proportion of variation explained (12.8% vs 10.1%) and concordance index (0.669 vs 0.615) compared with the American Thyroid Association version.

CONCLUSION

The revised American Thyroid Association initial and response-to-therapy risk stratifications have acceptable predictive value for persistent/recurrent papillary thyroid cancer patients.

Prevalence, Risk Factors And Location Of Skip Metastasis In Papillary Thyroid Carcinoma: A Systematic Review And Meta-Analysis

Background

Skip metastasis is a special type in cervical lymph node metastasis (LNM) of patients diagnosed with papillary thyroid carcinoma (PTC) which induced poor prognosis. There are few studies about skip metastasis and conclusions remained uncertain. Therefore, this study aims to explore the frequency and to investigate risk factors of skip metastasis in PTC.

Methods

Through searching the keyword by PubMed and Embase databases which articles published up to 1^st August 2018 about skip metastasis in papillary thyroid carcinoma, we extract data in order to assure whether those materials meet the criteria.

Results

The prevalence of skip metastasis is 12.02% in light of our meta-analysis of 18 studies with 2165 patients. The upper pole location (RR = 3.35, 95% CI =1.65-6.79, P = 0.0008) and tumors size ≤1 cm (RR = 2.65, 95% CI =1.50-4.70, P = 0.0008) are significantly associated with skip metastasis, whereas lymphovascular invasion (RR = 0.33, 95% CI =0.15-0.75, P = 0.0083) exists lower rate of skip metastasis. Multifocality, gender, age, bilaterality, thyroiditis and Extrathyroidal extension (ETE) are insignificantly associated with skip metastasis. Level II and level III are the most frequently affected areas.

Conclusion

The lateral compartment should be carefully examined especially for those PTC patients who present primary tumors in the upper lobe with a primary tumor size ≤10 mm which could be detected with skip metastasis.