Soft tissue invasion of papillary thyroid carcinoma

Risk factor analysis and prediction model construction for contralateral central lymph node metastasis in unilateral papillary thyroid carcinoma : Sex, extrathyroidal tumor extension (ETE), tumor diameter and ipsilateral central lymph node metastasis (ICLNM) are risk factor for unilateral papillary thyroid carcinoma (UPTC): a case control study

OBJECTIVE

To investigate contralateral central lymph node metastasis (CCLNM) in patients with unilateral papillary thyroid carcinoma (UPTC). To provide a reference for clinical decision-making, a prediction model for the probability of CCLNM was established.

METHOD

The clinicopathological data of 221 UPTC patients who underwent surgical treatment were retrospectively analyzed. Univariate and multivariate logistic regression analyses were performed to determine the independent risk factors for CCLNM according to clinicopathological characteristics, construct a prediction model to construct a visual nomogram, and evaluate the model.

RESULTS

According to univariate and multivariate logistic regression analyses, sex (P = 0.01, OR: 3.790, 95% CI: 1.373-10.465), extrathyroidal tumor extension (ETE) (P = 0.040, OR: 6.364, 95% CI: 1.083-37.381), tumor diameter (P = 0.010, OR: 3.674, 95% CI: 1.372-9.839) and ipsilateral central lymph node metastasis (ICLNM) (P < 0.001, OR: 38.552, 95% CI: 2.675-27.342) were found to be independent risk factors for CCLNM and were used to construct a nomogram for internal verification. The ROC curve had an AUC of 0.852 in the training group and an AUC of 0.848 in the verification group, and the calibration curve indicated that the prediction probability of the model was consistent with the actual probability. Finally, the analysis of the decision curve showed that the model has good application value in clinical decision-making.

CONCLUSION

Sex, ETE, tumor size, and ICLNM emerged as independent risk factors for CCLNM in UPTC patients. A predictive model was therefore developed, harnessing these variables to enable an objective, personalized estimation of CCLNM risk. This tool offers valuable insights to inform surgical planning and optimize treatment strategies for UPTC management.

Prognostic factors and treatment responses among patients with gross residual disease in differentiated thyroid cancer

BACKGROUND

Various postoperative staging systems were developed to assess the outcome of differentiated thyroid cancer from initial risk after surgery to dynamic changing prognosis during follow-up. The objective of our retrospective cohort study was to identify risk factors contributing to macroscopic positive surgical margin (R2 resection) and parameters in discriminating the treatment responses and prognosis among R2 patients.

METHODS

In total, 242 differentiated thyroid cancer patients with extrathyroidal extension who underwent a thyroidectomy at Kaohsiung Chang Gung Memorial Hospital between January 2013 and July 2018, were included. The patients were grouped according to the presence or absence of gross residual disease (R2). The R2 patients were further classified into two categories according to their treatment response into excellent and nonexcellent groups. The parameters and treatment outcomes were compared between these groups.

RESULTS

The mean follow-up time was 45.3 months. Two hundred seven (85.5%) patients had either surgery-free or microscopic margins (R0/R1), while 35 (14.5%) had R2 resection. In the R2 group (n = 35), 15 (42.9%) patients achieved an excellent response, while 20 (57.1%) achieved a nonexcellent response. Statistically significant differences were observed in the extent of neck dissection, TSH-Tg level, post-RAI Tg level, nodal status, and recurrence between the two groups. The Kaplan-Meier curves for 5-year local and distant recurrence-free survival of R0/R1 versus R2 patients were 90.0% versus 66.3%, and 98.4% versus 90.7%, respectively ( p < 0.001). Among the R2 patients, the excellent responders had a higher local recurrence-free survival than nonexcellent responders (93.3% vs. 45.1%, p = 0.008).

CONCLUSION

There are significant disparities in recurrence-free survival among R2 patients with different treatment responses. The nodal status of papillary thyroid cancer and thyroglobulin level after thyroidectomy and RAI were factors contributing to difference in their treatment responses.

A novel nomogram for identifying high-risk patients among active surveillance candidates with papillary thyroid microcarcinoma

Objective

Active surveillance (AS) has been recommended as the first-line treatment strategy for low-risk (LR) papillary thyroid microcarcinoma (PTMC) according to the guidelines. However, preoperative imaging and fine-needle aspiration could not rule out a small group of patients with aggressive PTMC with large-volume lymph node micro-metastasis, extrathryoidal invasion to surrounding soft tissue, or high-grade malignancy from the AS candidates.

Methods

Among 2,809 PTMC patients, 2,473 patients were enrolled in this study according to the inclusion criteria. Backward stepwise multivariate logistic regression analysis was used to filter clinical characteristics and ultrasound features to identify independent predictors of high-risk (HR) patients. A nomogram was developed and validated according to selected risk factors for the identification of an HR subgroup among "LR" PTMC patients before operation.

Results

For identifying independent risk factors, multivariable logistic regression analysis was performed using the backward stepwise method and revealed that male sex [3.91 (2.58-5.92)], older age [0.94 (0.92-0.96)], largest tumor diameter [26.7 (10.57-69.22)], bilaterality [1.44 (1.01-2.3)], and multifocality [1.14 (1.01-2.26)] were independent predictors of the HR group. Based on these independent risk factors, a nomogram model was developed for predicting the probability of HR. The C index was 0.806 (95% CI, 0.765-0.847), which indicated satisfactory accuracy of the nomogram in predicting the probability of HR.

Conclusion

Taken together, we developed and validated a nomogram model to predict HR of PTMC, which could be useful for patient counseling and facilitating treatment-related decision-making.

Causal inference between aggressive extrathyroidal extension and survival in papillary thyroid cancer: a propensity score matching and weighting analysis

Background

Extrathyroidal extension is a major risk factor for poor prognosis in papillary thyroid cancer. However, the effect of different degrees of extrathyroidal extension on prognosis remains controversial. We performed a retrospective study to elucidate how the extent of extrathyroidal extension in papillary thyroid cancer affected the clinical prognosis of patients and its covariates.

Methods

The study included 108,426 patients with papillary thyroid cancer. We categorized the extent of extension into none, capsule, strap muscles, and other organs. Three causal inference methods for retrospective studies, namely, inverse probability of treatment weighting, standardized mortality ratio weighting, and propensity score matching analysis, were used to minimize potential selection bias. Kaplan-Meier analysis and univariate Cox regression analyses were applied to analyze the precise effect of ETE on survival in papillary thyroid cancer patients.

Results

In the Kaplan-Meier survival analysis, only extrathyroidal extension into or beyond the strap muscles was statistically significant for both overall survival (OS) and thyroid cancer-specific survival (TCSS). In univariate Cox regression analyses before and after matching or weighting based on causal inference, extrathyroidal extension into soft tissues or other organs is a high-risk factor for both overall survival and thyroid cancer-specific survival. Sensitivity analysis revealed that lower overall survival was observed in patients with older age (≥55) and larger tumor size (>2 cm) of papillary thyroid cancer with extrathyroidal extension into or beyond the strap muscles.

Conclusions

Our study indicates that extrathyroidal extension into soft tissues or other organs is a high-risk factor in all papillary thyroid cancer. Even though invasion into the strap muscles did not seem to be a marker for poor prognosis, it still impaired the overall survival of patients with older age (≥55 years old) or larger tumor size (>2 cm). Further investigation is needed to confirm our results and to clarify further risk factors independent of extrathyroidal extension.

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.

Association of BMI with Clinicopathological Features of Papillary Thyroid Cancer: A Systematic Review and Meta-Analysis

BACKGROUND

Papillary thyroid cancer (PTC) is the most common subtype of thyroid cancer. The incidence of PTC is rising in tandem with an obesity epidemic. Associations have been demonstrated between increased body mass index (BMI) and worse oncological outcomes in a number of malignancies. However, research on this topic in PTC to date has been inconsistent, often due to limited data. This study aimed to measure the association between BMI and potentially adverse clinicopathological features of PTC.

METHODS

A meta-analysis of studies reporting outcomes after surgical treatment of PTC was performed. PubMed, Embase and the Cochrane Library were searched systematically to identify studies which provided data on BMI and clinicopathologic features of PTC. Relevant data were extracted and synthesis performed using adjusted odds ratios where available and crude values when not. Data were analysed by inverse variance using random and fixed effects models.

RESULTS

Data on 35,237 patients from 15 studies met the criteria for inclusion. Obesity was associated with larger tumour size (MD = 0.17 cm [0.05, 0.29]), increased rates of multifocality (OR = 1.41 [1.16, 1.70]), extrathyroidal extension (OR = 1.70 [1.39, 2.07]) and nodal spread (OR = 1.18 [1.07, 1.30]). Associations were more pronounced as BMI increased. There was no association between BMI and bilaterality, vascular invasion or metastatic spread.

CONCLUSION

Increased BMI is significantly associated with multiple potentially adverse features of PTC. The effect on long-term oncological outcomes requires further evaluation.

The new T3b category has clinical significance? SEER-based study

OBJECTIVE

As per the eighth edition of the American Joint Committee on Cancer (AJCC) staging system for differentiated thyroid carcinoma (DTC), minimal extrathyroidal extension (mETE) has been removed. Instead, gross ETE (gETE) invading only strap muscles has been designated as a new T3b category. Our objective was to investigate the impact of the T3b category on survival in order to establish its prognostic value in DTC.

DESIGN

In this retrospective study, we included patients who had undergone thyroidectomy between 2004 and 2012. Data from the Surveillance, Epidemiology and End Results (SEER) database were examined.

METHODS

We used the Kaplan-Meier method and log-rank test to analyse overall survival (OS) and cancer-specific survival (CSS). The effect of potential predictors associated with survival were estimated using the Cox regression model. To minimize selection bias, propensity-score matching (PSM) was performed.

RESULTS

A total of 63 315 patients were included in our study. During the average follow-up duration of nearly 78 months, significant differences were observed in cancer-specific survival among patients with no ETE, mETE, gETE invading only strap muscles (T3b) and gETE invading perithyroidal structures other than strap muscles (T4) (P < .05). In univariable and multivariate analysis, both mETE and T3b exhibited significant poorer CSS compared with no ETE. After adjusting for patient features with PSM, it was confirmed that T3b was associated with worse CSS compared with no ETE and mETE.

CONCLUSIONS

Both mETE and gETE are independent factors for DTC, implying that the new T3b category is worthy of reference for medical workers. Furthermore, mETE was significantly associated with poorer outcome. Our conclusion may provide support for the modification of the TNM staging system in the future.

TFF3 Contributes to Epithelial-Mesenchymal Transition (EMT) in Papillary Thyroid Carcinoma Cells via the MAPK/ERK Signaling Pathway

Trefoil factor 3 (TFF3) was found to be overexpressed in many types of tumours. Evidence has shown that TFF3 plays an important role in tumour proliferation, migration and invasion metastasis. However, the impact of TFF3 on patients' clinicopathological characteristics and underlying mechanisms remain unknown in papillary thyroid carcinoma (PTC). In this study, the expression of TFF3 and the epithelial-mesenchymal transition (EMT) transcriptional factor Snail in PTC and para-carcinoma specimens was evaluated by immunohistochemistry (IHC) and Western blot, and the possible associations with lymph node (LN) metastasis and other clinicopathological parameters were analysed. In vitro, the effect of TFF3 on the malignant behaviour of TPC-1 cells was evaluated by cell proliferation assays, cell adhesion assays, colony formation assays, wound-healing assays and transwell chamber invasion assays. EMT markers and regulatory molecules were detected by quantitative RT-PCR (qRT-PCR) and Western blot analysis in the TFF3-knockdown groups and shRNA control group. The results showed that TFF3 was upregulated in PTC tissue and was associated with lymph node metastasis (P=0.0001), pathological grade (P=0.0002) and Snail expression (P=0.0001). The knockdown of TFF3 markedly inhibited the abilities of TPC-1 cell proliferation, adhesion, colony formation, migration and invasion. Mechanically, the results demonstrated that TFF3 might activate the MAPK/ERK signalling pathways, affect the expression of the transcription factors snail and slug in addition to affecting EMT associated markers E-cadherin and N-cadherin, and accelerate the progression of EMT in TPC-1 cells. These findings indicate that TFF3 might promote the metastatic potential of PTC by promoting the EMT process through cascades of MAPK/ERK pathways.

Cervical Lymph Node Metastases of Papillary Thyroid Carcinoma, in the Central and Lateral Compartments, in Children and Adolescents: Predictive Factors

PROBLEM STATEMENT

The aim of our study was to identify predictive factors for lymph node metastases (LNM) in children and adolescents with papillary thyroid carcinoma (PTC) and their impact on survival.

METHODS

The authors conducted an Italian multicentric retrospective analysis on 132 pediatric patients (0-18 years old) affected by PTC between 2000 and 2014. The investigated variables were demographic characteristics of the patients, clinicopathological features of PTCs, and persistence/recurrence of disease. The female/male ratio was 3.1:1. The median age was 14.3 ± 3.5 years (range 4-18 years). Total thyroidectomy was performed in all the patients, followed by lymph node dissection in 87 patients (65.9%). Metastatic lymph node involvement was confirmed in 73 patients (55.3%): lateral compartment (LC) in 25 patients (34.2%), central compartment (CC) in 17 patients (23.3%), and both compartments in 31 patients (42.5%).

RESULTS

Multifocality (P < .00), vascular invasion (P = .04), infiltration of the thyroid capsule (P < .00), minimal extrathyroidal extension (P < .00), diffuse sclerosing variant of PTC (P = .02), and presence of LNM in the LC (P < .00) were significantly associated with LNM in CC. Infiltration of the thyroid capsule (P < .00), massive extrathyroidal extension (P = .03), distant metastases (P = .02), PTC, not otherwise specified (P < .00), and presence of LNM in the CC (P < .00) were significantly associated with LNM in LC. Age, sex and size of PTC were not correlated with the presence of cervical LNM. Moreover, presence of LNM in CC increases the risk of persistence (P < .01) and recurrence (P < .02) of PTC in children and adolescents.

CONCLUSIONS

Most predictors, unfortunately, are only identified post-operatively by histopathologic examination: Just a small part of them can be pre-operatively detected with a low-sensitivity neck ultrasonography. In PTC patients with pre-operative predictors, we suggest an accurate pre- and intra-operative evaluation of CC and/or LC to find suspicious lymph nodes. The presence of LNM in CC has an impact on disease/progression/relapse-free survival. We suggest performing RAI therapy and an accurate follow-up for pediatric patients with only post-operative predictors.

N-cadherin promotes thyroid tumorigenesis through modulating major signaling pathways

Epithelial-mesenchymal transition (EMT), a crucial step in disease progression, plays a key role in tumor metastasis. N-cadherin, a well-known EMT marker, acts as a major oncogene in diverse cancers, whereas its functions in thyroid cancer remains largely unclear. This study was designed to explore the biological roles and related molecular mechanism of N-cadherin in thyroid tumorigenesis. Quantitative RT-PCR (qRT-PCR) and immunohistochemistry assays were used to evaluate N-cadherin expression. A series of in vitro studies such as cell proliferation, colony formation, cell cycle, apoptosis, migration and invasion assays were performed to determine the effect of N-cadherin on malignant behavior of thyroid cancer cells. Our results showed that N-cadherin was significantly upregulated in papillary thyroid cancers (PTCs) as compared with non-cancerous thyroid tissues. N-cadherin knockdown markedly inhibited cell proliferation, colony formation, cell migration and invasion, and induced cell cycle arrest and apoptosis. On the other hand, ectopic expression of N-cadherin promoted thyroid cancer cell growth and invasiveness. Mechanically, our data demonstrated that tumor-promoting role of N-cadherin in thyroid cancer was closely related to the activities of the MAPK/Erk, the phosphatidylinositol-3-kinase (PI3K)/Akt and p16/Rb signaling pathways in addition to affecting the EMT process. Altogether, our findings suggest that N-cadherin promotes thyroid tumorigenesis by modulating the activities of major signaling pathways and EMT process, and may represent a potential therapeutic target for this cancer.