Young Age and Male Sex Are Predictors of Large-Volume Central Neck Lymph Node Metastasis in Clinical N0 Papillary Thyroid Microcarcinomas

The Number of Central Lymph Nodes on Preoperative Ultrasound Predicts Central Neck Lymph Node Metastasis in Papillary Thyroid Carcinoma: A Prospective Cohort Study

To evaluate the effectiveness of the number of central compartment lymph nodes (CLNs) on ultrasound (US) in predicting CLN metastasis (CLNM). We prospectively studied 309 papillary thyroid cancer (PTC) patients who underwent thyroidectomy with CLN dissection at our center from May 2017 to July 2017. The number and features of CLNs were evaluated preoperatively via US. All US examinations were performed using a Philips iU 22 or a GE Logiq 9 machine. Correlations between CLNs observed via preoperative US and amount of CLNM were evaluated. We found that ≥2 CLNs on the preoperative US was associated with CLNM (P < 0.01). For this feature, the sensitivity, specificity, and area under the curve (AUC) were 54.3%, 66.1%, and 0.61, respectively. The presence of both suspected metastasis and ≥2 CLNs on US had a specificity of 86.5%. In addition, ≥3 CLNs on preoperative US was associated with large-volume CLNM (>5 metastatic CLNs) (P < 0.01). For this feature, the sensitivity, specificity and AUC were 54.8%, 74.5% and 0.65, respectively. The presence of both suspected metastasis and ≥3 CLNs on US had a specificity of 84.9%. The presence of suspected metastasis and/or ≥3 CLNs had a sensitivity of 80.6%. Our results suggest that ≥2 and ≥ 3 CLNs on preoperative US may serve as ancillary preoperative markers for predicting CLNM.

Predictive Factors of Central-Compartment Lymph Node Metastasis for Clinical N0 Papillary Thyroid Carcinoma With Strap Muscle Invasion

Background: Papillary thyroid carcinoma (PTC) patients with anterior extrathyroidal extension (ETE) involving the strap muscle have a relatively better prognosis than those with posterior gross ETE involving the recurrent laryngeal nerve. Whether prophylactic central-compartment lymph node dissection (CLND) should be performed in PTCs with only strap muscle invasion (SMI) is still unclear. Methods: A retrospective cohort study was conducted in clinical N0 (cN0) PTC patients with SMI who underwent thyroid surgery from 2009 to 2017. A total of 152 patients were included, and predictive factors of central-compartment lymph node metastasis (CLNM) were determined. Results: Among the 281 PTCs patients with SMI, 152 (51.1%) did not clinically present with lymph node metastasis. Microscopic CLNM was identified in 77 (50.7%) cN0 PTC patients with SMI. According to the univariate and multivariate analyses, male patients and those aged <40 years were more likely to be diagnosed with CLNM than female patients and those aged >40 years (odds ratio [OR] = 6.22 [95% confidence interval (CI), 1.43-27.10], p = 0.02 vs. OR = 9.94 [95% CI, 2.79-35.44], p = 0.00). The CLNM positive rate of male patients aged <40 years was 87.5%, while that for female patients aged ≥55 years was 23.8%. However, risk factors associated with large-volume CLNM were not identified because of the small number of patients. Conclusions: Taken together, nearly half of PTC patients with SMI did not clinically present with lymph node metastasis. Male sex and patients aged <40 years were identified as the predictive factors of CLNM in cN0 PTCs with SMI. Hence, the results of this single-center study raise the possibility that prophylactic CLND may be more often considered for younger male PTC patients with SMI.

Active Surveillance of Papillary Thyroid Microcarcinoma: Where Do We Stand?

The recent sharp increase in thyroid cancer incidence is mainly due to increased detection of small papillary thyroid microcarcinoma (PTMC). Due to the indolent nature of the disease, active surveillance (AS) of low-risk PTMCs is suggested as an alternative to immediate surgery to reduce morbidity from surgery. For appropriately selected PTMC patients, AS can be a good management option and surgical intervention can be safely delayed until progression occurs. Many considerations must be taken into account at the time of initiation of AS, including radiological tumor characteristics and clinical characteristics of the patient. A specialized medical team should be assembled to monitor patients during AS with an appropriate follow-up protocol. The fact that some patients require surgery for disease progression after long-term follow-up is a major drawback of the current AS protocol. Evaluation of tumor kinetics by three-dimensional tumor volume measurement during the initial 2-3 years of AS may be helpful for discrimination of PTMCs that need early surgical intervention. In this review, we will discuss the clinical outcomes of surgical intervention and AS, considerations during AS, and unresolved questions about AS.

Lymph node metastasis in lung squamous cell carcinoma and identification of metastasis-related genes based on the Cancer Genome Atlas

Squamous cell carcinoma (SCC) is a unique clinical and histological category that accounts for about 30% of total lung cancer. To identify risk factors for lymph node metastasis and analyze the molecular features of these metastases in lung SCC, a retrospective study was performed for 170 lung SCC patients who underwent surgical treatment. The overall survival of these patients with or without lymph node metastasis (LM/NLM) was analyzed using the Kaplan‐Meier method. We also used the TCGA database to compare the differentially expressed genes (DEGs) in patients with stage T1‐2 and T3‐4 lung SCC. Data from both our retrospective study and the TCGA database demonstrated a correlation between age and stage T1‐T2 LM (P = .002). There were significant differences between the LM and NLM groups in both mean survival time and median survival time for different T‐stages (P = .031). There were 176 upregulated and 177 downregulated DEGs between the LM and NLM groups in the stage T1‐2 group and 93 upregulated and 34 downregulated DEGs in the stage T3‐T4 group. These differentially expressed genes were predicted to participate in five cellular components, five molecular functions, and five biological processes. There were 20 genes, including GCG, CASR, NPY, CGA, TAC1, ALB, APOA1, CRH, CHRH, TRH, and GHSR, located at the core of the protein‐protein interaction network in the stage T1‐2 group and 11 genes, including F2, CASR, GRM1, GNRHR, GRPR, NTSR1, PROKR2, UTS2D, PTH, ALB, and FGA, in the stage T3‐4 group. Overall, LM plays a key role in the treatment response and prognosis of SCC patients. Several risk factors, including age and stage, were identified for LM. There was a previously undiscovered enrichment of significant novel genes in lung SCC between the LM and NLM groups, which may have the potential for predicting prognosis and targeting.

The Efficacy and The Safety of Ultrasound-guided Ablation Therapy for Treating Papillary Thyroid Microcarcinoma

The prevalence of papillary thyroid microcarcinoma (PTMC) increases rapidly all around the world, but the management of PTMC hasn't reached a consensus. Recently, ultrasound-guided (US-guided) ablation therapy was introduced as a feasible treatment for low-risk PTMC. The clinical application of US-guided ablation therapy needs doctors' effort to investigate the efficacy and the safety of US-guided ablation in treating PTMC carefully. Although the present evidence showed some limitations, such as short-term study time spans and no randomized control design, in our perspective, US-guided thermal ablation therapy has good short-term efficacy and safety and is a promising PTMC's treatment in future clinical practice.

The role of prophylactic central compartment lymph node dissection in elderly patients with differentiated thyroid cancer: a multicentric study

BACKGROUND

Prophylactic central neck lymph-nodes dissection is still a topic of major debate in Literature. There is a lack of randomized controlled trials proving advantages in its application in terms of overall survival and local recurrence. Due to the recent rapid increase of elderly population, differentiated tumor carcinoma diagnosis increased in patients over 65 years old. The aim of this study was to compare recurrence rate, complications rate and histological features of tumors in elderly population.

METHODS

A retrospective study was carried out collecting data from 371 patients with differentiated thyroid cancer without clinical evidence of lymph-nodes involvement in three Italian referral centers from 2005 to 2015. All patients were aged ≥ 65 years and were divided in two groups based on the performed surgery (total thyroidectomy alone or associated with central lymph-nodes dissection). Moreover, patients were stratified according to the age between 65 and 74 years old and over 75 years old.

RESULTS

Total thyroidectomy alone was performed in 184 patients (group A) and total thyroidectomy with prophylactic central neck dissection was performed in 187 cases (group B). There was a statistically significant difference in complications between the groups in terms of neck hematoma (0.5% group A vs 3.7% group B), temporary hypoparathyroidism (11.4% group A vs 21.4% group B), and temporary unilateral recurrent nerve injury (1.5% group A vs 6.4% group B). Lymph nodes recurrence rate was 9.2% in group A and 8.5% in group B, with no statistically significant difference. There was a statistically significant difference in patients over 75 years old in terms of temporary hypoparathyroidism (24% group A vs 11% group B), permanent hypoparathyroidism (2,7% group A vs 0,3% group B) and recurrent nerve injury (9,5% group A vs 2% group B).

CONCLUSIONS

The role of prophylactic central neck dissection is still controversial, especially in elderly patients, and an aggressive surgical approach should be carefully evaluated. The Authors reported a similar low recurrence rate between total thyroidectomy and total thyroidectomy associated with prophylactic central neck dissection, with increased postoperative complications in the lymphadenectomy group and in patients over 75 years old, advocating a tailored surgical approach in elderly population.

Recent Trends in the Clinicopathological Features of Thyroid Nodules in Pediatric Patients: A Single Tertiary Center Experience over 25 Years

BACKGROUND

The trends in pediatric patients having thyroid nodules have not been well evaluated. Here, we analyzed the clinicopathological features of the children who have presented with thyroid nodules at our center over several decades in order to determine a change of trend.

MATERIALS AND METHODS

We analyzed 215 pediatric patients who had undergone a thyroidectomy between 1990 and 2014 at our single tertiary center. The clinicopathological features were analyzed according to age, sex, and the year of diagnosis.

RESULTS

The most common reason for hospital admission was a palpable anterior neck mass (76.7%). The males in the patient cohort were younger than the females (13 vs. 15 years old, p < 0.05). The female patients increased from 50.0% to 83.0% with age (p < 0.05). The rate of malignancy did not increase with age (p < 0.05). However, the malignancy rate was higher in the more recently seen patients (23.8% during the early study period and 86.8% in the late study period; p < 0.05).

CONCLUSION

Following a thyroidectomy in children with thyroid nodules, there was no change in the rate of detection of thyroid cancer over time with age, although the detected frequency of malignancy has increased in more recent patients. Therefore, early thyroid nodule detection for malignant screening is likely to be required for pediatric patients in the near future.

Can Active Surveillance be an Alternative to Surgery in Papillary Thyroid Microcarcinoma?: The Current Situation Worldwide

Papillary thyroid carcinoma is the most common endocrine malignancy. Papillary thyroid microcarcinomas (PTMCs) are tumors with a size of ≤1 cm. The biological behavior of these tumors differs due to the presence of their aggressive features. The prognosis of PTMCs with high-risk features, such as clinical node metastasis, distant metastasis, and significant extrathyroidal extension to the tracheal or recurrent laryngeal nerve invasion, is poor, even if a sufficient immediate surgery is performed at diagnosis. However, PTMCs without these aggressive features are low-risk tumors because of their indolent and slow growth behaviors. The increase in thyroid cancer incidence is mostly a result of overdiagnosis of small low-risk PTMCs with indolent clinical course. Despite the sudden increase in thyroid cancer incidence worldwide, cancer mortality did not increase. Although the traditional treatment strategy for PTMC is immediate surgery at diagnosis, because of the rather low disease-specific mortality rate, low recurrence rate, and potential risk for postoperative complications, active surveillance has been proposed recently as an alternative option for PTMCs without invasion, metastasis, or cytological or molecular characteristics. The recent data support that active surveillance of low-risk PTMC should be the initial treatment modality, because only a small percentage of low-risk PTMCs show signs of progression, and delayed surgery has not caused significant recurrence. However, recent management guidelines are shifting toward more conservative treatments, such as active surveillance. Although there is an increase in the number of studies related to active surveillance, prospective studies have been mostly from academic referral centers in Japan. The world still needs class 1 evidence extended prospective studies originating from different geographic regions. Active surveillance may be a good alternative to immediate surgery for appropriately selected patients with PTMC.

Active Surveillance of Low-Risk Papillary Thyroid Microcarcinoma: A Multi-Center Cohort Study in Korea

BACKGROUND

Active surveillance has been introduced as a management option for low-risk papillary thyroid microcarcinoma (PTMC) due to its mostly indolent course.

METHODS

This was a multicenter study of 370 PTMC patients who underwent active surveillance more than one year. The changes in volume and maximum diameter between initial and last ultrasonography were evaluated to identify the natural course of PTMC during active surveillance.

RESULTS

Patients' age at diagnosis was 51 ± 12 years, and 110 (30%) patients were <45 years of age. The initial maximum diameter and volume of PTMCs were 5.9 ± 1.7 mm and 81.0 ± 77.7 mm³, respectively. During the median 32.5 months of follow-up, 86 (23.2%) patients were found to have an increase in tumor volume, and 13 (3.5%) patients showed an increase in the maximal diameter of the tumor. The cumulative incidence of volume increase gradually rose with time (6.9%, 17.3%, 28.2%, and 36.2% after two, three, four, and five years, respectively). The risk of volume increase in patients <45 years of age was twice as high as in older patients (p = 0.002). There was no significant difference in tumor size change according to sex, levothyroxine treatment, or presence of Hashimoto's thyroiditis. During the period, 58 (15.7%) patients underwent delayed thyroid surgery due to anxiety (37.9%), tumor size increase (32.8%), or appearance of cervical lymph node metastasis (8.6%). Lymph node metastasis was found in 29.3% of patients on pathological examination.

CONCLUSIONS

A significant number of PTMCs grow during active surveillance, and tumor volume change is a more sensitive means of evaluating tumor growth. Active surveillance can be carefully applied for selected patients. Although it is not contraindicated, it should be applied more cautiously for younger patients.

A retrospective study of the clinical features in papillary thyroid microcarcinoma depending on age

The aim of this study was to evaluate the clinical features and correlation of neck lymph node involvement of papillary thyroid microcarcinoma (PTMC) according to patients’ age. We divided the patients into three groups according to age: young group (<45 years, n=83), middle group (45–54 years, n=80), and old group (≥55 years, n=53). The clinical features among the different groups were analyzed retrospectively. All of the 216 patients had received radioiodine ablation at least one time. Among these, 84 patients had central lymph node metastasis (CLNM), 11 patients had lateral lymph node metastasis (LLNM), and 26 patients had both CLNM and LLNM. We show that both lymph node metastasis (LNM) and the CLNM rate were significantly higher in young patients compared with old patients (P=0.000 and 0.000, separately). The radioactive iodine curative ratio in younger patients is also lower than that in the other two groups (37.35, 18.75, and 32.08%, separately, P=0.029). Further Bonferroni test among three groups identified that both LNM and the CLNM rate were significantly higher in the young group than in the old group (P=0.000 and 0.000, separately). Logistic regression analysis showed that young [odds ratio (OR): 2.087, 95% confidence interval (CI): 1.013–4.299, P=0.046] and middle age (OR: 4.049, 95% CI: 1.933–8.482, P=0.000), and extrathyroid extension (OR: 1.952, 95% CI: 1.027–3.711, P=0.041) are independent risk factors for neck LNM. Unlike LNM, young age (<45 years) (OR: 3.667, 95% CI: 1.732–7.761, P=0.001), extrathyroid extension (OR: 2.256, 95% CI: 1.189–4.282, P=0.013), and male sex (OR: 2.057, 95% CI: 1.042–4.061, P=0.038) were found to be independent risk factors for CLNM. However, no independent risk factors were found to be associated with LLNM. The patients with PTMCs had different clinical features according to age. PTMCs in young patients were more aggressive, especially in LNM. Hence, clinicians should consider an individualized treatment according to age in younger patients to achieve better therapeutic efficacy.

Cell adhesion-related gene somatic mutations are enriched in aggressive papillary thyroid microcarcinomas

Background

Approximately half of the documented increases in differentiated thyroid carcinoma is due to identification of papillary thyroid microcarcinomas (PTMCs). Knowing whether PTMC is aggressive is required for proper treatment, but until now, there has been no method for assessing these traits and understanding the underlying mechanisms for aggressiveness.

Methods

We performed whole-exome sequencing of 16 PTMCs and matched normal thyroid tissues and GO/KEGG analysis to study genetic alterations and biological consequences associated with aggressive PTMCs, and then sequenced these genes using a next-generation gene-panel approach in an additional 70 PTMC samples including aggressive (n = 50) and non-aggressive (n = 20) groups.

Results

We identified 254 somatic mutations of 234 genes, for which 178 mutations in 168 genes were found in the aggressive group, and 76 mutations in 74 genes were found in the non-aggressive group. Several recurrent mutations in BRAF, VCAN, ALDH1L1, and MUC5B were identified, and many novel but infrequent mutations in other genes were also found. The aggressive cohort had more mutational burdens than the non-aggressive group (P = 0.004). Nonsynonymous mutations of 13 genes (MUC5B, TNN, SSPO, PPFIA1, PCDHGA2, ITGA8, ITGA4, DCHS1, CRNN, ROCK1, RELN, LAMC2, and AEBP1) were involved in cell adhesion, and these were only present in the aggressive group. Targeted sequencing of these genes revealed significant enrichment in the aggressive group (P = 0.000004).

Conclusion

PTC may have evolved from PTMC due to sharing similar gene mutations, and the accumulation of such mutations promoted the aggressiveness of PTMC. Gene mutants associated with cell adhesion may be used to predict PTMC aggressiveness and allow more selective treatment.

Evolving management considerations in active surveillance for micropapillary thyroid carcinoma

PURPOSE OF REVIEW

To summarize developments on active surveillance for micropapillary thyroid cancers, with a focus on strategies for optimal risk stratification and caveats that currently limit adoption.

RECENT FINDINGS

Observational trials encompassing thousands of active surveillance patients worldwide have increasingly demonstrated the viability of active surveillance for small, low-risk thyroid cancers. Collectively, these data have established that with proper patient selection and strict monitoring, more than 85% of such cases remain indolent no meaningful clinical growth over at least 10 years. Moreover, to date no cases of symptomatic progression or distant metastasis have been reported, and that delayed treatment when needed has not led to unresectable disease or higher risk of complications. Deeper investigation to better predict clinical progression is necessary to improve patient selection, given concerns regarding patient anxiety, age eligibility, and underestimation of true disease extent.

SUMMARY

Compelling data from ongoing trials support active surveillance as a first-line management option for micropapillary thyroid carcinomas. Proper risk stratification and strict monitoring protocols will be necessary to sustain the excellent results achieved to date. Broad adoption of active surveillance will require further education, collaboration, and equipoise between physicians and patients to optimize such individualized treatment plans.

The role of two tumor foci for predicting central lymph node metastasis in papillary thyroid carcinoma: A meta-analysis

BACKGROUND AND OBJECTIVE

Two tumor foci are the most common in multifocal papillary thyroid carcinoma, but whether they should be regarded as the indicator of central lymph node metastasis remains unclear. To investigate the role of two tumor foci for predicting central lymph node metastasis, we performed a meta-analysis of published studies.

METHODS

We performed a systematic literature search of PubMed, Embase and Web of Science prior to September 29, 2017. The relevant articles were examined and the eligible studies were included to assess the metastatic risk of central lymph node in papillary thyroid carcinoma with one, two and more than two (>2) tumor foci.

RESULTS

Five eligible studies included 4045 patients in this meta-analysis. Two tumor foci were the most common in multifocal papillary thyroid carcinoma (63.8%, 939/1471). Multifocality group showed a higher risk of central lymph node metastasis compared with unifocality group (odds ratio: 1.58, 95% confidence interval: 1.37-1.81). The risk of central lymph node metastasis was higher in two tumor foci group than unifocality group (odds ratio: 1.38, 95% confidence interval: 1.17-1.62). However, this risk in two tumor foci group was lower than >2 tumor foci group (odds ratio: 0.62, 95% confidence interval: 0.42-0.92). Begg's test revealed no obvious publication bias.

CONCLUSION

This meta-analysis suggested that two tumor foci should be regarded as the predictive factor of central lymph node metastasis, but the role of it was less important than three or more than three tumor foci. Understanding the role of two tumor foci for predicting central lymph node metastasis may help clinicians make an optimal decision of treatment and the extent of surgery for multifocal papillary thyroid carcinoma.

[Surgery of papillary thyroid microcarcinoma]

BACKGROUND

Different countries are currently reporting a substantial increase in the incidence rates of papillary thyroid microcarcinoma (PTMC).

OBJECTIVE

Presentation of diagnosis and surgical therapy of PTMC and discussion of a more conservative approach, such as active surveillance.

MATERIAL AND METHODS

Overview of the current guidelines from different countries and analysis of recent publications reporting the results of active surveillance of PTMC from Japan, Korea and the USA.

RESULTS

The majority of international guidelines for PTMC recommends thyroid lobectomy as the gold standard. Active surveillance as an alternative procedure is described in the Japanese guidelines (JSTS/JAES). Present surveillance studies including more than 1700 patients report a tumor growth in 8-14% of the cases during a median follow-up of up to 75 months. Tumor growth and lymph node metastases are detected most frequently in younger patients (below 40-50 years).

CONCLUSION

Active surveillance might serve as an alternative treatment option for older patients with PTMC. Since the median follow-up periods are currently not long enough, it seems difficult to draw definite conclusions of this procedure right now.

Active Surveillance of Papillary Thyroid Microcarcinoma: A Mini-Review from Korea

In Korea, the incidence of thyroid cancer increased explosively in the early 2000s, and reached a plateau in the early 2010s. Most cases of newly diagnosed thyroid cancer are small indolent microcarcinoma and could be good candidates for active surveillance (AS) instead of immediate surgery. Many considerations must be taken into account for establishing selection criteria for candidates for AS of papillary thyroid microcarcinoma (PTMC), including the characteristics of the tumor, the patient, and the medical team. If possible, AS of PTMC should be a part of a prospective clinical trial to ensure long-term safety and to identify clinical and/or molecular markers of the progression of PTMC. In this review, we discuss lessons regarding surgical interventions for PTMC, and then describe the concept, application, caveats, unanswered questions, and future perspectives of AS of PTMC. For appropriately selected patients with PTMC, AS can be a good alternative to immediate surgery.