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

The m6A methyltransferase METTL3 drives thyroid cancer progression and lymph node metastasis by targeting LINC00894

BACKGROUND

Long noncoding RNAs (lncRNAs) are significant contributors to various human malignancies. The aberrant expression of lncRNA LINC00894 has been reported in various human malignancies. We aimed to illustrate the role of LINC00894 and its underlying mechanism in the development of papillary thyroid carcinoma (PTC).

METHODS

We performed bioinformatics analysis of differentially expressed RNAs from TCGA and GEO datasets and selected the target lncRNA LINC00894. SRAMP analysis revealed abundant M6A modification sites in LINC00894. Further analysis of StarBase, GEPIA, and TCGA datasets was performed to identify the related differentially expressed genes METTL3. Colony formation and CCK-8 assays confirmed the relationship between LINC00894, METTL3, and the proliferative capacity of PTC cells. The analysis of AnnoLnc2, Starbase datasets, and meRIP-PCR and qRT‒PCR experiments confirmed the influence of METTL3-mediated m6A modification on LINC00894. The study employed KEGG enrichment analysis as well as Western blotting to investigate the impact of LINC00894 on the expression of proteins related to the Hippo signalling pathway.

RESULTS

LINC00894 downregulation was detected in PTC tissues and cells and was even further downregulated in PTC with lymphatic metastasis. LINC00894 inhibits the lymphangiogenesis of vascular endothelial cells and the proliferation of cancer cells. METTL3 enhances PTC progression by upregulating LINC00894 by enhancing LINC00894 mRNA stability through the m6A-YTHDC2-dependent pathway. LINC00894 may inhibit PTC malignant phenotypes through the Hippo signalling pathway.

CONCLUSION

The METTL3-YTHDC2 axis stabilizes LINC00894 mRNA in an m6A-dependent manner and subsequently inhibits tumour malignancy through the Hippo signalling pathway.

Risk factors associated with preferential lateral lymph node metastasis in papillary thyroid carcinoma

BACKGROUND

Lateral lymph node metastasis (LLNM) is common in patients with papillary thyroid cancer (PTC), usually occurring after central lymph node metastasis (CLNM). However, some patients experience LLNM without first developing CLNM. This study aimed to identify the risk factors for developing LLNM without CLNM.

METHODS

We retrospectively reviewed 421 patients diagnosed with PTC who underwent lobectomy or total thyroidectomy with central and ipsilateral lateral lymph node dissection. We collected clinicopathological data and used univariate and multivariate logistic regression analyses to determine the risk factors associated with LLNM without CLNM.

RESULTS

The LLNM without CLNM frequency was 18.3% (77/421). Univariate analyses demonstrated that age over 55 years, primary tumor in the upper portion of the thyroid, the number of central lymph node (CLN) and LLNM, primary tumor size, and the summed size of multi-foci tumors smaller than 1 cm were significantly associated with LLNM without CLNM (p < 0.05). Multivariate analysis revealed that LLNM without CLNM was more likely to occur in patients aged ≥55 years (odds ratio [OR], 2.309; 95% confidence interval [CI], 1.133-4.704; p = 0.021), and primary tumor in the upper portion of the thyroid (OR, 0.524; 95% CI, 0.295-0.934; p = 0.028).

CONCLUSION

The lymph node metastasis pattern in patients with PTC is not constant. Therefore, surgeons should evaluate the lateral lymph nodes, especially in patients older than 55 years or when the primary tumor is in the upper portion of the thyroid.

Extent of cervical lymph node dissection: Recommendations from the Francophone Association for Endocrine Surgery, the French Society of Endocrinology and the French Society of Nuclear Medicine

When metastatic ipsilateral central lymph nodes from thyroid cancer are identified pre- or intraoperatively (cN1a), ipsilateral central lymph node dissection should be performed concomitantly with thyroidectomy. When the patient is N1a on one side, contralateral prophylactic central lymph node dissection can also be considered. Prophylactic ipsilateral lymph dissection is not recommended. Ipsilateral compartment lymph node dissection is recommended in the corresponding sector for treatment of thyroid cancer with lymph node involvement (cN1b). Lymph node dissection can be limited to sectors III and IV when one of these sectors (or both) is involved and ultrasound does not demonstrate involvement of the other lateral sectors. Associated prophylactic lymph node dissection of sectors IIA and IIB is not recommended, while lymph node dissection of sector V (and exceptionally sector I) is indicated only when metastatic lymph nodes are proven. Prophylactic lymph node dissection of sector VB can be considered when positive lymph nodes are identified in sectors II, III and IV. When isolated metastatic lateral lymph nodes are identified (cN1b), prophylactic central (sector VI) lymph node dissection is recommended on the same side as the lateral compartment in addition to ipsilateral lateral lymph node compartment dissection. The level of evidence is insufficient to recommend prophylactic lateral lymph node dissection on the contralateral side for unilateral cN1b tumors. This type of lymph node dissection can be discussed for tumors that are at high risk of recurrence, bilateral tumors, in case of ipsilateral lateral lymph nodes > 3cm or in presence of > 4 metastatic lymph nodes in the central compartment.

Case Report: A papillary thyroid microcarcinoma patient with skip lymph node metastasis and multiple distant metastasis

Papillary thyroid carcinoma (PTC) is the most common type of thyroid cancer. Papillary thyroid microcarcinoma (PTMC) is defined as PTC with a diameter less than 1 centimeter. Most lymph nodes of PTC patients have metastasized to the central neck, and a few lymph nodes have metastasized to the lateral neck. Skip lymph node metastasis, that is, lateral cervical lymph node metastasis without central lymph node metastasis, is even less common. Additionally, distant metastasis of PTMC is also rare, mainly occurring in the lung and bone. Here, we reported a case of PTMC patient with skip lymph node metastasis and multiple distant metastasis. The patient presented with a huge shoulder mass and the primary tumor was found to originate from the thyroid. However, the patient only suffered with PTMC via postoperative pathological results, and interestingly, the patient only had skip lymph node metastasis. Thus, we should focus on PTMC patients with lateral cervical lymph nodes metastasis, especially those with skip metastasis. In addition, this case provides a new perspective for us to understand of skip lymph metastasis and distant metastasis of PTMC.

Risk factors for skip metastasis in patients with papillary thyroid microcarcinoma

BACKGROUND

Lymph node metastasis (LNM) is prevalent in papillary thyroid microcarcinoma (PTMC) and is essential when determining tumor stage and prognosis. Positive lateral LNM with negative central LNM is defined as skip metastasis. Thyroid carcinoma's risk factors for skip metastasis remain controversial, especially in PTMC. This study aimed to determine the clinical features as well as the risk factors of skip metastasis among patients with PTMC.

METHODS

We conducted retrospective research among patients with PTMC who were subjected to treatment at our Hospital between January 2018 and December 2019 by reviewing their medical records. A database containing demographic characteristics, ultrasonography features, blood test outcomes, operation information, pathology details, and follow-up information was constructed. The link between skip metastasis and clinicopathological features of PTMC was evaluated using univariate as well as multivariate analyses.

RESULTS

Overall, 293 patients diagnosed with PTMC and lateral LNM were included. There were 91 men (31.1%) and 202 women (68.9%). The median age was 38 (31-47) years. Fifty patients were diagnosed with skip metastases. Levels III and II + III were the most prevalent in single-level and two-level metastasis, correspondingly. Univariate and multivariate analyses detected two independent factors linked to skip metastasis in PTMC: female sex (odds ratio = 2.609, 95% confidence interval (CI): 1.135-6.000; p = 0.024) and location of the tumor (upper portion) (odds ratio = 2.959, 95% CI: 1.552-5.639; p = 0.001).

CONCLUSIONS

Skip metastasis is prevalent in thyroid carcinoma. Female sex and tumor location (upper portion) are independently linked to skip metastasis in PTMC. Patients who have these two risk factors should undergo a meticulous preoperative and intraoperative evaluation of lymph node status.

Effect of skip metastasis to lateral neck lymph nodes on outcome of patients with papillary thyroid carcinoma

CONTEXT

Lymph node metastasis (N1) is a prognostic factor for disease recurrence in papillary thyroid carcinoma (PTC) patients. Skip metastasis is defined as only lateral N1 with negative central lymph nodes (LNs).

OBJECTIVE

The aim of this study was to explore the outcome of PTC patients with skip N1.

PATIENTS AND DESIGN

All patients who underwent a total thyroidectomy with ipsilateral central and lateral LN dissection for PTC from 1999 to 2019 in a high-volume endocrine surgery centre were included in this study.

MAIN OUTCOME MEASURE

Demographic and outcomes-recurrence and disease-specific survival (DSS)-were compared between three groups: N1a (central N1 only), N1b-CL (central and lateral N1), and N1b-Skip (lateral N1 without central LN involvement).

RESULTS

During the study period, 3046 patients had surgery for PTC, including 1138 with N1 (37%, 860 women, mean age: 44.8 years) comprising 474 N1a (42%), 513 N1b-CL (45%), and 151 N1b-Skip (13%). The median follow-up was 74 months (range 12-216 months). The recurrence rate in the N1b-Skip group was 13% (20/151) and 10% (47/474) in the N1a group. This was significantly lower than that in the N1b-CL group (27%, 140/513) (p < 0.0001). DSS at 10 years was 99% for group N1a, 98% for the N1b-CL, and 99% in the N1b-Skip group.

CONCLUSION

The recurrence rate of N1b-Skip patients was lower than that of N1b-CL patients and similar to that of N1a patients. This result could be used as an indication for the modality of radioiodine therapy, and for the pattern of follow-up procedures.

[Risk factors of skip lateral cervical lymph node metastasis in papillary thyroid carcinoma]

Objective:To investigate the incidence and risk factors of skip lateral cervical lymph node metastasis in patients with papillary thyroid carcinoma（PTC）. Methods:The clinical and pathological data of 85 patients with PTC who underwent total thyroidectomy plus central and lateral neck dissection in the Department of Otolaryngology Head and Neck Surgery, the First Affiliated Hospital of Hebei North University from January 2018 to January 2022 were analyzed retrospectively. SPSS 26.0 software was used to process the data, and univariate and multivariate analysis were performed to assess the relationships between skip lateral cervical lymph node metastasis and clinicopathological characteristics. Results:There were 31 cases（36.5%） of skipped lateral cervical lymph node metastasis. Univariate analysis showed that the largest tumor diameter ≤5 mm（P=0.006） and the tumor located in the upper pole of the thyroid（P=0.002） were associated with the occurrence of skip lateral cervical lymph node metastasis in patients with PTC. Most of the skip metastases involved a single area（18/31, 58.1%）, of which area Ⅲ was most likely to be involved（10/31, 32.3%）, followed by area Ⅱ（5/31, 16.1%）. The results of binary logistic analysis showed that tumor diameter less than 5 mm（OR 7.800, 95%CI 1.710-21.394, P=0.005） and tumor at the upper pole of the gland（OR 4.060, 95%CI 1.468-11.235, P=0.007） were independent risk factors of skip lateral cervical lymph node metastasis in PTC patients. Conclusion:PTC patients with tumor diameter ≤5 mm and tumor located in the upper pole of the gland are more prone to skip lateral cervical lymph node metastasis. When the diameter of the tumor is less than 5 mm and the tumor is located at the upper pole of the gland, careful evaluation should be made before operation, even in the absence of central lymph node metastasis, attention should be paid to the possibility of lateral cervical lymph node metastasis.

Is Performance of Routine Central Compartment Neck Dissection in cN0 Papillary Thyroid Cancers Really Useful? 10-Year Prospective Observational Study

Central compartment nodes of neck are the first echelon nodes in papillary thyroid cancers (PTC). This study analyses the adverse parameters associated with central compartment nodal metastasis in cN0 PTC and also the usefulness of performing central compartment neck dissection routinely. A total of 236 patients with cNo PTC who underwent prophylactic central compartment neck dissection, from January 2008 to June 2017 in the Department of Oncology, Madurai Medical College, were included in study. Analysis of various adverse factors associated with central compartment nodal metastasis was made. Patients (46.18%) had metastatic nodes in the central compartment. Incidence of nodal metastasis increased with tumour size, capsular invasion, extrathyroidal extension, tracheal invasion and pulmonary metastasis. More than 50% patients did not have any of the statistically significant known adverse risk factors except for age and sex. Routine central compartment neck dissection has therapeutic value in PTC even in absence of known adverse factors and can be recommended in cases of clinically negative nodes. A meticulous dissection in experienced hands carries less complication rates as with thyroidectomy alone. In a resource limited country like ours, where the cost of re-surgery and radioiodine scans are high, a meticulous initial surgery incorporating central compartment neck dissection would really mean a difference.

A Risk Stratification Model for Metastatic Lymph Nodes of Papillary Thyroid Cancer: A Retrospective Study Based on Sonographic Features

BACKGROUND

Papillary thyroid carcinoma (PTC) has a high probability of cervical lymph node (LN) metastasis. The aim of the study was to develop an ultrasound risk stratification model to standardize the diagnosis of metastatic LNs of PTC.

METHODS

Patients with suspicious thyroid nodules who underwent US examination and US guided fine-needle aspiration for cervical LNs were retrospectively collected. Univariate and multivariate logistic regression analyses were performed to assess the independent risk factor of metastatic LNs. According to the OR value of correlated indicators in logistic regression analysis, a risk stratification model was established.

RESULTS

A total of 653 LNs were included. The independent risk factors of metastatic LNs were long-axis diameter/short-axis ≤ 2 (OR=1.644), absence of hilum (OR=1.894), hyperechogenicity (OR=5.375), calcifications (OR=6.201), cystic change (OR=71.818), and abnormal flow (OR=3.811) (P<0.05 for all). The risk stratification model and malignancy rate were as follows: 0-2 points, malignancy rate of 10.61%, low suspicion; 3-5 points, malignancy rate of 50.49%, intermediate suspicion, ≥6 points, malignancy rate of 84.81%, high suspicion. The area under the receiver operating characteristic curve for the model was 0.827 (95% CI 0.795-0.859).

CONCLUSIONS

Our established risk stratification model can effectively evaluate metastatic LNs in the patients with suspicious thyroid nodules, and it might provide a new strategy choice for clinical practice.

A Novel and Effective Model to Predict Skip Metastasis in Papillary Thyroid Carcinoma Based on a Support Vector Machine

INTRODUCTION

Skip metastasis, referred to as lymph node metastases to the lateral neck compartment without involvement of the central compartment, is generally unpredictable in papillary thyroid carcinoma (PTC). This study aims to establish an effective predictive model for skip metastasis in PTC.

METERIALS AND METHODS

Retrospective analysis was performed of clinical samples from 18192 patients diagnosed with thyroid cancer between 2016 to 2020. The First Affiliated Hospital of Wenzhou Medical University. The lateral lymph node metastasis was occureed in the training set (630 PTC patients) and validation set (189 PTC patients). The univariate and multivariate analyses were performed to detect the predictors of skip metastasis and the support vector machine (SVM) was used to establish a model to predict skip metastasis.

RESULTS

The rate of skip metastasis was 13.3% (84/631). Tumor size (≤10 mm), upper location, Hashimoto's thyroiditis, extrathyroidal extension, absence of BRAFV600E mutation, and less number of central lymph node dissection were considered as independent predictors of skip metastasis in PTC. For the training set, these predictors performed with 91.7% accuracy, 86.4% sensitivity, 92.2% specificity, 45.2% positive predictive value (PPV), and 98.9% negative predictive value (NPV) in the model. Meanwhile, these predictors showed 91.5% accuracy,71.4% sensitivity, 93.1% specificity, 45.5% PPV, and 97.6% NPV in validation set.

CONCLUSION

This study screened the predictors of the skip lateral lymph node metastasis and to establish an effective and economic predictive model for skip metastasis in PTC. The model can accurately distinguish the skip metastasis in PTC using a simple and affordable method, which may have potential for daily clinical application in the future.

Exploring Somatic Alteration Associating With Aggressive Behaviors of Papillary Thyroid Carcinomas by Targeted Sequencing

Wisely differentiating high-risk papillary thyroid carcinoma (PTC) patients from low-risk PTC patients preoperatively is necessary when comes to making a personalized treatment plan. It is not easy to stratify the risk of patients according to sonography or lab results before surgery. This study aims to seek out potential mutation gene markers that may be helpful in stratifying the risk of PTC. A custom panel of 439 PTC relevant and classic tumor metabolic pathway relevant genes was designed. Targeted capture sequencing was performed on 35 pairs of samples from 35 PTC tumors and 35 para-tumor thyroid tissues obtained during surgery. Variant calling and detection of cancer gene mutations were identified by bio-information analysis. Ingenuity Pathway Analysis (IPA) was performed to do functional enrichment analysis of high-frequency mutant genes. Immunohistochemistry (IHC) was performed on 6 PTC patients to explore the expression of protein associated with interested genes. Event-free survival (EFS) was calculated to determine which genes might affect the prognosis of patients. We have identified 32 high-frequency mutant genes in PTC including BRAF. RBL2 was found to be significantly correlated to event-free survival, FOXO1, MUC6, PCDHB9, NOTCH1, FIZ1, and RTN1 were significantly associated with EFS, while BRAF mutant was not correlated to any of the prognosis indicators. Our findings in this study might open more choices when designing thyroid gene panels used in FNA samples to diagnose PTC and predict the potentially aggressive behavior of PTC.

Role of the 2018 American Thyroid Association statement on postoperative hypoparathyroidism: a 5-year retrospective study

Background

Definitions of postoperative hypoparathyroidism (hypoPT) have never reached consent until the American Thyroid Association (ATA) statement was released, with new characteristics and challenges.

Methods

Patients with papillary thyroid carcinoma who underwent primary total thyroidectomy between January 2013 and June 2018 were retrospectively enrolled. Symptoms of hypocalcemia and their frequency were stringently followed. Patients were divided into groups according to the ATA statement. Incidence of postoperative hypoPT and serum parathyroid hormone levels accompanied by calcium levels, from 1-day to at least 24-month follow-up.

Results

A total of 1749 patients were included: 458 (26.2%) had transient and 63 (3.6%) had permanent hypoPT. Transient hypoPT was found in 363 (20.7%) patients with biochemical hypoPT, 72 (4.1%) with clinical hypoPT, and 23 (1.3%) with relative hypoPT; permanent hypoPT was detected in 8 (0.5%) patients with biochemical hypoPT, 55 (3.1%) with clinical hypoPT, and none with relative hypoPT. Female sex, age ≥ 55 years, unintentional parathyroid gland resection, and autotransplantation of ≥ 2 parathyroid glands were independent risk factors for transient biochemical hypoPT. Age ≥ 55 years, bilateral central neck dissection, and isthmus tumor location were independent risk factors for transient clinical hypoPT. A postoperative 1-day percentage of parathyroid hormone (PTH) reduction of > 51.1% was an independent risk factor for relative hypoPT (odds ratio, 4.892; 95% confidence interval, 1.653–14.480; P = 0.004). No independent risk factor for permanent hypoPT was found.

Conclusion

ATA diagnostic criteria for postoperative hypoPT are of great value in differentiating patients by hypocalcemia symptoms and choosing corresponding clinical assistance; however, they may underestimate the actual incidence.

Research trends for papillary thyroid carcinoma from 2010 to 2019: A systematic review and bibliometrics analysis

BACKGROUND

Thyroid carcinoma comprises the fastest rising incidence of carcinomas over the past decade. Papillary thyroid carcinoma (PTC) is the most predominant type of thyroid carcinoma. This study aimed to assess the research trends in the field of PTC.

METHODS

Publications from January 2010 to December 2019 were retrieved from the Web of Science Core Collection database using Thompson Reuters. Searching strategies were determined according to Medical Subject Heading terms. Different kinds of bibliometrics software, such as HistCite and VOSviewer, and online bibliometrics analysis platforms were utilized to evaluate and visualize the results.

RESULTS

A total of 8102 publications across 93 countries were identified, with the annual number of publications showing an increasing trend. The United States, China, and South Korea showed their dominant position in PTC publication outputs, H-index, total citations, and international collaborations. Thyroid was the most productive journal. Akira Miyauchi published the most articles, and the most productive institution was Yonsei University. The hotspots keywords proliferation, invasion and metastasis, diagnoses and prognoses, therapeutic resistance, recurrence, and microcarcinomas appeared earlier and were sustained over the last 3 years.

CONCLUSIONS

This bibliometric study provides a comprehensive analysis delineating the scientific productivity, collaboration, and research hotspots within the PTC field, which will be very helpful when focusing on the direction of research over the next few years.

Protective strategy of parathyroid glands during thyroid lobectomy: A retrospective cohort and case-control study

Parathyroid protection during thyroid lobectomy was not illustrated previously. Aim of this study was to find out the influence of parathyroid glands in situ preservation and autotransplantation on postoperative parathyroid function in thyroid lobectomy.Consecutive patients who underwent primary thyroid lobectomy with unilateral central neck dissection for papillary thyroid carcinoma in our center were included retrospectively. Postoperative hypoparathyroidism was defined as low parathyroid hormone (PTH) levels (<1.6 pmol/L) and keeping over 6 months was defined as permanent. Patients were divided into 3 groups: all identified parathyroid glands preserved in situ (preservation group); at least one parathyroid gland autotransplanted without accidental resection (autotransplantation group); at least one parathyroid gland accidental resected (resection group).A total of 425 patients were included. No permanent hypoparathyroidism was reported, and the rates of transient hypoparathyroidism were similar among all groups. Significantly lower serum PTH levels were found in autotransplantation group versus preservation group at postoperative 1-day (3.77 ± 1.61 vs 4.72 ± 2.31, P < .001). Transient hypoparathyroidism was significantly associated with reduced intraoperative carbon nanoparticles utilization (57.1% vs 77.4%, P = .039).Thyroid lobectomy was a safe surgical method for parathyroid protection no matter the practice to ipsilateral parathyroid glands. However, preservation of all parathyroid glands was still recommended considering relatively stable PTH levels.

Prediction of ipsilateral lateral cervical lymph node metastasis in papillary thyroid carcinoma: a combined dual-energy CT and thyroid function indicators study

BACKGROUND

Predicting the possibility of ipsilateral lateral cervical lymph node metastasis (ipsi-LLNM) was crucial to the operation plan for patients with papillary thyroid carcinoma (PTC). This study aimed to investigate the independent risk factors for ipsi-LLNM in PTC patients by combining dual-energy computed tomography (DECT) with thyroid function indicators.

METHODS

We retrospectively enrolled 406 patients with a pathological diagnosis of PTC from Jan 2016 to Dec 2019. Ensure the DECT images were clear and the thyroid function indicators were complete. Univariate and multivariate logistic analyses explored the independent risk factors for ipsi-LLNM. To evaluate the cutoff value of each risk factor by using receiver operating characteristic (ROC) curves.

RESULTS

A total of 406 patients with PTC were analyzed, including 128 with ipsi-LLNM and 278 without ipsi-LLNM. There were statistical differences of parameters between the two groups (P < .0001), including serum Tg, Anti-Tg, Anti-TPO, the volume of the primary lesion, calcification, extrathyroidal extension (ETE), and iodine concentration (IC) in the arterial and the venous phases. Independent risk factors for ipsi-LLNM included serum Tg, Anti-Tg, ETE, and IC in the arterial and the venous phases (P < .05). The combined application of the above independent risk factors can predict the possibility of ipsi-LLNM, with an AUC of 0.834. Ipsi-LLNM was more likely to occur when the following conditions were met: with ETE, Tg >  100.01 ng/mL, Anti-Tg >  89.43 IU/mL, IC in arterial phase > 3.4 mg/mL and IC in venous phase > 3.1 mg/mL.

CONCLUSIONS

The combined application of DECT quantitative parameters and thyroid function indicators can help clinicians accurately predict ipsi-LLNM before surgery, thereby assisting the individualized formulation of surgical procedures.

Surgical strategy when identifying less than four parathyroid glands during total thyroidectomy: a retrospective cohort study

Background

Parathyroid glands protection is still controversial in patients with less than 4 parathyroid glands during thyroidectomy. The aim of this study was to investigate the strategy of parathyroid autotransplantation or in situ preservation in patients with 3 parathyroid glands.

Methods

Consecutive patients who underwent primary total thyroidectomy with bilateral central neck dissection for papillary thyroid carcinoma (PTC) in our center were included retrospectively. Serum calcium and parathyroid hormone (PTH) levels (pg/mL), incidence of hypocalcemia and hypoparathyroidism during 24 months follow-up were compared grouping by the number of parathyroid glands both identified intraoperatively and confirmed postoperatively by pathology.

Results

A total of 1,424 patients were included. Serum PTH and calcium levels were lower and the incidence of hypocalcemia was higher in patients with 3 identified parathyroid glands. When excluding patients with accidental parathyroid resection, the results remained similar. Of the 212 patients with 3 identified parathyroid glands, PTH levels at postoperative 12-month in patients underwent autotransplantation were significantly lower than patients with all parathyroid glands preserved in situ (3.65±1.30 vs. 4.67±1.89, P=0.026).

Conclusions

The parathyroid function was weaker in patients with 3 parathyroid glands than patients with 4 before and after operation. Parathyroid glands preserved all in situ promoted better recovery of postoperative function in patients with 3 identified parathyroid glands.

A Specific Predicting Model for Screening Skip Metastasis From Patients With Negative Central Lymph Nodes Metastasis in Papillary Thyroid Cancer

Skip metastasis is a specific type of papillary thyroid cancer lymph node metastasis (LNM). The present study aimed to clarify the typical clinical characteristics of skip metastasis and optimize the prediction model, so as to provide a more individual treatment mode for skip metastasis. We retrospectively analyzed 1075 PTC patients with different lymph node metastasis statuses from two clinical centers. Comparisons have been made between patients with skip metastasis and other types of LNM. Univariate and multivariate analyses were performed to detect the risk factors for skip metastasis with negative LNM, and a nomogram for predicting skip metastasis was established. The rate of skip metastasis was 3.4% (37/1075). Compared with other types of LNM, significant differences showed in tumor size, upper portion location, thyroid capsular invasion, and ipsilateral nodular goiter with the central lymph node metastasis (CLNM) group, and in age and gender with the lateral lymph node metastasis (LLNM) group. Four variables were found to be significantly associated with skip metastasis and were used to construct the model: thyroid capsular invasion, multifocality, tumor size > 1 cm, and upper portion. The nomogram had good discrimination with a concordance index of 0.886 (95% confidence interval [CI], 0.823 to 0.948). In conclusion, the significant differences between skip metastasis and other types of LNM indicated that the lymph node drainage pathway of skip metastasis is different from either CLNM or LLNM. Furthermore, we established a nomogram for predicting risk of skip metastasis, which was able to effectively predict the potential risk of skip metastasis in patients without preoperative LNM clue.

A nomogram to predict skip metastasis in papillary thyroid cancer

Background

Skip metastases are defined as lateral lymph node metastasis (LNM) without the involvement of central LNM in papillary thyroid cancer (PTC), and it is difficult to predict in clinical practice. Our study aimed to investigate the risk factors of skip metastasis and establish a nomogram for predicting the probability of skip metastasis in PTC patients.

Patients and methods

A total of 378 consecutive PTC patients with clinically suspected LNM who underwent modified radical neck dissection (MRND) from March 2018 to July 2019 in our hospital were enrolled. Univariate and multivariate analyses were used to examine risk factors of skip metastasis, and a nomogram prediction model was established and internally validated.

Results

The incidence of skip metastases was 11.6% (44/378). Primary tumor size of ≤ 1 cm (OR = 2.703; 95% CI, 1.342–5.464; P = 0.005), age (OR = 1.051; 95% CI, 1.017–1.805; P = 0.005), and primary tumor location in the upper portion (OR = 6.799; 95% CI, 2.710–17.060; P < 0.001) were found to be independent risk factors for skip metastasis in PTC patients. A nomogram based upon these predictors performed well. The area under the curve (AUC) was 0.806 (95% CI, 0.736–0.876), and the P value of the Hosmer-Lemeshow goodness of fit test was 0.66. Decision curve analysis revealed that the nomogram was clinically useful.

Conclusion

Based on the risk factors of skip metastasis, a high-performance nomogram was established, which can provide an individual risk assessment and can guide treatment decisions for patients.

Thyroid cancer neck lymph nodes metastasis: Meta-analysis of US and CT diagnosis

PURPOSE

Ultrasound (US) is the first imaging technique in the assessment of cervical lymph nodes metastasis (LNM) of papillary thyroid cancer (PTC) patients preoperatively. Computed tomography (CT) exerts an influence on surgical strategy especially for patients with lateral cervical LNM. This meta-analysis aimed at assessing the diagnostic values of US and CT in detecting the cervical LNM in thyroid cancer patients.

METHODS

Medline, Embase and Cochrane Library (CENTRAL) were retrieved up to 16^th Sep, 2019 for studies about comparison of the diagnostic performance between US and CT. The pooled sensitivity, specificity, positive likelihood ratio (LR), negative LR and diagnostic odds ratio (DOR), with each's 95 % CI were calculated.

RESULTS

A total of 5656 thyroid cancer patients in 10 studies were included. CT had a higher sensitivity in central (0.400 [0.385, 0.416] vs 0.284 [0.270, 0.298], P < 0.001), lateral (0.811 [0.778, 0.416] vs 0.758 [0.722, 0.792], P = 0.029) and the whole (0.664 [0.633, 0.694] vs 0.593 [0.561, 0.625], P = 0.002) compartments regions. US had a higher specificity in central (0.895 [0.885,0.903] vs 0.950 [0.944, 0.956], P < 0.001), lateral (0.84 [0.813,0.864] vs 0.88 [0.856, 0.901], P = 0.012) and the whole (0.834 [0.804,0.862] vs 0.911 [0.887, 0.932], P < 0.001) compartments regions.

CONCLUSIONS

US and CT performed poorly when trying to identify the presence of central LNM. CT has a higher sensitivity while US has a higher specificity for the assessment of central, lateral and the whole cervical LNM. Performing CT to detect the lateral cervical LNM will effectively reduce the rate of missed diagnosis and improve surgical planning. Both US and CT are needed for neck lymph nodes staging preoperatively owning to low sensitivities.

Risk stratification for lateral involvement in papillary thyroid carcinoma patients with central lymph node metastasis

PURPOSE

To effectively predict lateral neck lymph nodes (LLN) metastasis in papillary thyroid carcinoma (PTC) patients with central lymph nodes (CLN) invasion, and devise targeted treatment strategies.

METHODS

Four hundred and thirty-four PTC patients with CLN metastasis from two medical centers were retrospectively analyzed. A new statistical model was established for predicting LLN involvement in these patients to guide lymph nodes management strategies.

RESULTS

Patients with more than five positive CLN metastasis appeared to have extremely high risk (83.0%) of LLN involvement. For patients with five or less positive CLN invasion, multivariate logistic analyses were applied. Independent risk factors for LLN involvement were determined to be: age over 40, maximum tumor diameter of no less than 1.0 cm, existence of thyroid capsular invasion, and tumor with ipsilateral nodular goiter (iNG). These factors were used to construct a predictive nomogram. The accuracy and validity of our newly built model were verified by C-index 0.761 (95% CI, 0.707-0.815) in development cohort and 0.759 (95% CI, 0.745-0.773) in validation cohort and calibration curve. The patients were stratified into three groups based on their nomogram risk scores. Possible LLN involvement rates for low-risk, moderate-risk, and relatively high-risk subgroups were 8.9%, 22.8%, and 48.2%, respectively.

CONCLUSIONS

Our newly established model can effectively predict possible LLN metastasis in PTC patients, and a new strategy selection flow chart was created for patients with positive CLN invasion. For patients in high-risk group, prophylactic LLN dissection is recommended, if not, adjuvant radioactive iodine or a closer follow-up scheme should at least be conducted. For those in low-risk group, surgical intervention is unnecessary and regular follow-up is recommended.