Distinct genetic changes characterise multifocality and diverse histological subtypes in papillary thyroid carcinoma

The Differences Between Multifocal and Unifocal Papillary Thyroid Carcinoma in Unilateral Lobe: A Meta-Analysis

Background

As many inconsistent reports on the clinical manifestations and prognosis between unilateral unifocal PTC (UUPTC) and unilateral multifocal PTC (UMPTC), identifying the difference should guide management. The purpose of this study was to investigate other additional differences between UUPTC and UMPTC in addition to their difference in the number of cancer foci.

Data Sources

A systematic literature search was conducted in the PubMed and Web of Science databases for relevant studies published before December 31, 2020. Their reference lists were also reviewed.

Review Methods

Two reviewers independently extracted data and assessed the quality of eligible studies. Studies on patients who underwent an open thyroidectomy with or without neck dissection were included. Data were analyzed using the RevMan 5.3 software.

Results

Fifteen studies comprising 9,665 patients were selected for the meta-analysis. UMPTC occurred in 10% to 36% of all PTC cases. There were no significant differences between UMPTC and UUPTC patients in age, gender, tumor size, and extrathyroidal extension (ETE). However, significant differences (P < 0.05) between UMPTC and UUPTC patients were observed in central lymph node metastasis (CLNM), lateral lymph node metastasis (LLNM), tumor-node-metastasis (TNM) stage I+II, TNM stage III+IV, the recurrence/persistence of the UMPTC group after total thyroidectomy and overall recurrence/persistence.

Conclusion

UMPTC patients are more likely to have CLNM, LLNM, more advanced TNM stage, and recurrence/persistence than UUPTC patients. Compared with UUPTC, UMPTC patients should undergo central lymph node dissection, and pay more attention to LLNM, TNM stage and recurrence/persistence during the follow-up.

Prevalence and predictor for malignancy of contralateral thyroid nodules in patients with unilateral PTMC: a systematic review and meta-analysis

BACKGROUND

The presence of clinically negative nodules on the contralateral lobe is common in patients with unilateral papillary thyroid microcarcinoma (PTMC). The appropriate operational strategies of contralateral thyroid nodules remain controversial. In this study, we analyzed clinical features that could be predictors for malignancy of contralateral thyroid nodules coexisting with diagnosed unilateral PTMC.

METHODS

The literatures published from January 2000 to December 2019 were searched in PubMed, Cochrane Library, Embase, Web of Science, CNKI, and Wan Fang database. Odds ratio (OR) with 95% CI was used to describe categorical variables. Heterogeneity among studies was examined by the Q test and I2 test; potential publication bias was detected by Harbord test and 'trim and fill' method.

RESULTS

In this meta-analysis, 2541 studies were searched and 8 studies were finally included. The results showed that the rate of carcinoma in contralateral nodules was 23% (OR = 0.23, 95% CI = 0.18-0.29). The pooled data indicated that contralateral malignancy was not associated with age, gender, primary lesion size, ipsilateral central lymph node metastasis and multifocality of contralateral lesion. The following variables have correlations with an increased risk of contralateral malignancy: multifocality of primary carcinomas (OR = 3.93, 95% CI = 2.70-5.73, P < 0.0001), capsular invasion (OR = 1.61, 95% CI = 1.10-2.36, P = 0.01), and Hashimoto's thyroiditis (OR = 1.57, 95% CI = 1.13-2.20, P = 0.008).

CONCLUSIONS

Based on our meta-analysis, the rate at which contralateral malignancies are preoperatively misdiagnosed as benign is 23%. The risk factors for contralateral malignancy in unilateral PTMC patients with contralateral clinical negative nodules include multifocality of primary carcinomas, capsular invasion, and Hashimoto's thyroiditis.

Bilateral papillary thyroid cancer in children: Risk factors and frequency of postoperative diagnosis

BACKGROUND

The recommendation for children with papillary thyroid cancer (PTC) is total thyroidectomy (TT) based on the incidence of bilateral disease. Evaluating this assumption, we reviewed the characteristics of bilateral PTC in a large cohort of children.

METHODS

A retrospective chart review for patients surgically treated for PTC from 2009 to 2018 analyzing preoperative risk factors, ultrasound findings, and pathology results was performed. Bilateral disease was defined as pathologic PTC in the contralateral lobe, including microscopic disease.

RESULTS

Of the 172 patients included, 38.4% had bilateral disease with 23% diagnosed postoperatively. Multifocal disease on ultrasound was associated with bilateral disease (OR 2.9, 95% CI 1.5-5.9, p = 0.002). Nodule dimension >2 cm was associated with increased risk for postoperative bilateral disease (OR 3.5, 95% CI 1.6-7.4, p = 0.001). Patients with bilateral disease were more likely to have extrathyroidal extension, lymphovascular invasion, positive central lymph nodes, and extranodal extension (p < 0.001 for all). Diffuse-sclerosing variant PTC was also associated with bilateral disease.

CONCLUSION

Thirty-eight percent of children were diagnosed with PTC demonstrate bilateral disease. Nearly one in four have occult bilateral disease. The features that predicted bilateral disease were multifocality, widely invasive PTC on ultrasound, and the presence of lymphadenopathy. Thus, TT is the appropriate surgical approach for pediatric patients with PTC.

TYPE OF STUDY

Clinical Research, Retrospective Review.

LEVEL OF EVIDENCE

Level IV.

Clinical and pathologic predictors of central lymph node metastasis in papillary thyroid microcarcinoma: a retrospective cohort study

OBJECTIVE

To identify the clinical and pathological predictors of central lymph node metastasis (CLNM) in patients with clinically lymph node-negative papillary thyroid microcarcinoma (PTMC).

MATERIALS AND METHODS

Data pertaining to 541 clinically lymph node-negative PTMC patients who underwent thyroid surgery at the Shanghai General Hospital between January 2010 and December 2013 were retrospectively analyzed. According to histopathological evidence of central lymph node involvement, patients were divided into central lymph node metastasis (CLNM)-positive and CLNM-negative groups; risk factors for CLNM were identified statistically.

RESULTS

LNM was found in 148 (27.4%) patients. Gender (P = 0.002), age (P < 0.001), tumor size (P < 0.001), multifocality (P < 0.001), and extrathyroidal extension (P < 0.001) were significantly different between CLNM-positive and CLNM-negative groups. On multivariate analyses, male sex (odds ratio [OR] = 2.656), age <45 years (OR = 4.184), tumor size >0.575 cm (OR = 2.105), gross extrathyroidal extension (OR = 14.605) and multifocality (OR = 2.084) were independent risk factors for CLNM. Among patients who did not have any of these five risk factors, only 3.9% were found to have CLNM.

CONCLUSIONS

A relatively high prevalence of CLNM was observed in patients with clinically lymph node-negative PTMC. CLNM was associated with male sex, younger age, larger tumor size, extrathyroidal extension and multifocal PTMC.

How Many Contralateral Carcinomas in Patients with Unilateral Papillary Thyroid Microcarcinoma are Preoperatively Misdiagnosed as Benign?

BACKGROUND

The decision to perform a total thyroidectomy (TT) for unilateral papillary thyroid microcarcinoma (PTMC) with nodules in the contralateral lobe remains controversial. The aim of this study was to investigate the rate of contralateral carcinomas that are preoperatively misdiagnosed as benign.

METHODS

From October 2011 to October 2015, a total of 347 patients with unilateral PTMC and contralateral benign nodules who were treated with a TT at a single institution were enrolled. All patients underwent preoperative fine needle aspiration and ultrasonography (US). Clinicopathological features such as age, sex, laterality, tumor size, central lymph node metastases, capsular invasion, TgAb and TPOAb levels, Hashimoto's thyroiditis, nodule number in both lobes according to preoperative US, and primary carcinoma number in the final postoperative pathology report were all analyzed to investigate the rate and predictive factors of contralateral carcinoma.

RESULTS

A total of 100 patients (28.9 %) were diagnosed with papillary thyroid carcinoma in the contralateral lobe. A multivariate analysis showed that tumor size, nodule number in the contralateral lobe, and multifocality of the primary tumor were all independent predictive factors of contralateral carcinoma in patients with unilateral PTMC and contralateral benign nodules.

CONCLUSIONS

According to our findings, the rate at which contralateral carcinomas are preoperatively misdiagnosed as benign is 28.9 %. A TT is essential for unilateral PTMC with a primary tumor size >5 mm, multifocal primary carcinomas or multifocal benign nodules in the contralateral lobe.

Clinicopathological relevance of antithyroglobulin antibodies in low-risk papillary thyroid cancer

OBJECTIVE

The extent of initial surgical management in papillary thyroid cancer (PTC) is controversial. We examined whether the presence of perioperative antithyroglobulin antibodies (TGA) could predict long-term recurrence and occurrence of adverse features among a homogenous group of patients with PTC.

METHODS

The clinical features of patients with PTC treated at a single institution (Jewish General Hospital, McGill University, Montreal, Canada) were obtained from the medical records, and all clinicopathologic information was reviewed. Only low-risk PTC without clinical evidence of nodal disease before surgery and treated with 30 mCi of radioactive iodine was included in the study.

RESULTS

The chart review retrieved 361 patients with a median follow-up of 85.0 months (Q25-Q75 73-98). Forty-two (11.6%) patients had presence of perioperative TGA. Perioperative TGAs were associated with present extrathyroidal extension (P=.005), unsuspected nodal disease (P=.001) and autoimmune thyroiditis (P<.0001). Overall, 17 (4.7%) patients experienced locoregional recurrence. Perioperative TGAs were a significant predictor of recurrence in univariable (P=.021) but not in multivariable analysis (P=.13).

CONCLUSION

Presence of perioperative TGAs is associated with aggressive histological features and the presence of thyroiditis. Detection of TGA perioperatively may encourage surgeons to consider more extensive initial surgery.

Quality of life and cosmetic result of single-port access endoscopic thyroidectomy via axillary approach in patients with papillary thyroid carcinoma

BACKGROUND

Endoscopic thyroidectomy for minimally invasive thyroid surgery has been widely applied in the past decade. The present study aimed to evaluate the effects of single-port access transaxillary totally endoscopic thyroidectomy on the postoperative outcomes and functional parameters, including quality of life and cosmetic result in patients with papillary thyroid carcinoma (PTC).

PATIENTS AND METHODS

Seventy-five patients with PTC who underwent endoscopic thyroidectomy via a single-port access transaxillary approach were included (experimental group). A total of 123 patients with PTC who were subjected to conventional open total thyroidectomy served as the control group. The health-related quality of life and cosmetic and satisfaction outcomes were assessed postoperatively.

RESULTS

The mean operation time was significantly increased in the experimental group. The physiological functions and social functions in the two groups were remarkably augmented after 6 months of surgery. However, there was no significant difference in the scores of speech and taste between the two groups at the indicated time of 1 month and 6 months. In addition, the scores for appearance, satisfaction with appearance, role-physical, bodily pain, and general health in the experimental group were better than those in the control group at 1 month and 6 months after surgery.

CONCLUSION

The single-port access transaxillary totally endoscopic thyroidectomy is safe and feasible for the treatment of patients with PTC. The subjects who underwent this technique have a good perception of their general state of health and are likely to participate in social activities. It is worthy of being clinically used for patients with PTC.

Relevance of BRAF and NRAS mutations in the primary tumor and metastases of papillary thyroid carcinomas

BACKGROUND

Multifocality of papillary thyroid carcinoma (PTC) is common. BRAF and NRAS mutations are the most frequent genetic alterations in PTC. The purpose of this study was to determine the distribution and relevance of BRAF^T1799A and NRAS mutations in PTC.

METHODS

BRAF^T1799A and NRAS mutations were evaluated in 195 intrathyroid or metastatic foci from 29 patients with multifocal PTC.

RESULTS

BRAF^T1799A mutation was positive in 46.7% of the 59 intrathyroid and 136 metastatic foci (91/195 foci). Heterogeneous BRAF pattern was observed in 51.7% patients (15/29 patients). Irrespective of BRAF status at diagnosis (thyroid or nodes), all patients with recurrent PTC presented BRAF-mutated metastases during follow-up. All foci were negative for NRAS mutations.

CONCLUSION

BRAF but not NRAS mutations were heterogeneously distributed among primary tumor, nodal sites, and recurrent disease. The BRAF status of metastases generated during the follow-up can differ from the status of foci at diagnosis. © 2016 Wiley Periodicals, Inc. Head Neck 38: 1772-1779, 2016.

Risk Factors for Nodal Metastasis in cN0 Papillary Thyroid Microcarcinoma

BACKGROUND

Despite the majority of papillary thyroid microcarcinoma (PTMC) patients having an excellent prognosis, cervical lymph node metastases are common. The purpose of this study was to investigate the incidence and the predictive risk factors for occult central compartment lymph node metastasis (CLNM) in PTMC patients.

MATERIALS AND METHODS

178 patients with clinically node-negative (cN0) PTMC undergoing prophylactic central compartment neck dissection in our hospital from January 2008 to Jun 2010 were enrolled. The relationship between CLNM and the clinical and pathological factors such as gender, age, tumor size, tumor number, tumor location, extracapsular spread (ECS), and coexistance of chronic lymphocytic thyroiditis was analyzed.

RESULTS

Occult CLNM was observed in 41% (73/178) of PTMC patients. Multivariate analysis showed that male gender, tumor size (≥6mm) and ECS were independent variables predictive of CLNM in PTMC patients.

CONCLUSIONS

Male gender, tumor size (≥6mm) and ECS were risk factors of CLNM. We recommend a prophylactic central lymph node dissection (CLND) should be considered in PTMC patients with such risk factors.

Bilaterality weighs more than unilateral multifocality in predicting prognosis in papillary thyroid cancer

Papillary thyroid cancer (PTC) often presents as multifocal tumor;, however, whether multifocality is associated with poor prognosis remains controversial. The aims of this retrospective study were to identify the characteristics of PTC with multifocal tumors and evaluate the association between the location and prognosis. We reviewed the medical records of 496 patients who underwent total thyroidectomy for PTC. Patients were classified as three groups: N1 (solitary tumor), N2 (2 or more foci within unilateral lobe of thyroid), and N3 (bilateral tumors, at least one tumor focus for each lobe of thyroid). We analyzed the differences of clinicopathologic features and clinical outcomes among the three groups. Cox regression model was used to assess the relation between the different locations of multifocal tumors and prognosis. Although the differences of clinicopathologic features such as the size of tumor, extrathyroidal extension, and cervical lymph node metastasis were not significant among the three groups, the bilateral-multifocality was proved to be an independent risk factor for neck recurrence (hazard ratio (HR) = 4.052, 95 % confidence interval (CI) 2.070-7.933), distant metastasis (HR = 3.860, 95 % CI 1.507-9.884), and cancer death (HR = 7.252, 95 % 2.189-24.025). In addition, extrathyroidal extension (HR = 2.291, 95 % CI 1.185-4.427) and older age >45 years (HR = 6.721, 95 % CI 2.300-19.637) were also significant predictors for neck recurrence and cancer death, respectively. Therefore, bilateral-multifocality as an indicator for more extensive tumor location could be used to assess the risk of recurrence and mortality in PTC. Given the poor prognosis associated with bilateral-multifocality and other risk factors, aggressive therapy and intensive follow-up were recommended for PTC patients with them.

Number of tumor foci predicts prognosis in papillary thyroid cancer

Background

Papillary thyroid cancer (PTC) often presents as multifocal. However, the association of multifocality with poor prognosis remains controversial. The aim of this retrospective study was to identify the characteristics of PTC with multiple foci and to evaluate the association between multifocality and prognosis.

Methods

We reviewed the medical records of 496 patients who underwent total thyroidectomy for PTC. Patients were classified as G1 (1 tumor focus), G2 (2 foci), and G3 (3 or more foci). We analyzed the clinicopathological features and clinical outcomes in each classification. A Cox regression model was used to assess the relationship between multifocality and recurrence or cancer mortality.

Results

The G1, G2 and G3 groups included 287, 141 and 68 patients, respectively. The mean age was 47.1 ± 16.1 yr in G1, 41.1 ± 18.4 yr in G2, and 35.5 ± 15.9 yr in G3 and differed significantly among the 3 groups (p = 0.001). The proportion of extrathyroidal extension, central lymph node metastasis (CLNM), and lateral lymph node metastasis (LLNM) in the G1 to G3 groups increased with increasing number of tumor foci. The Kaplan–Meier curves revealed that G3 had the shortest recurrence-free survival, and differences were significant among the 3 groups (p = 0.001, Log Rank test). Furthermore, cancer-specific survival rates decreased significantly with increasing number of tumor foci (p = 0.041). Independent predictors of recurrence by multivariate Cox analysis included >3 tumor foci [HR 2.60, 95% confidence interval (CI) 1.53-4.39, p = 0.001] and extrathyroidal extension (HR 1.95, CI 1.12-3.38, p = 0.018).

Conclusion

An increase in the number of tumors is associated with a tendency toward more aggressive features and predicts poor prognosis in PTC.

A Case of Multifocal Papillary Thyroid Carcinoma Consisting of One Encapsulated Follicular Variant with BRAF K601E Mutation and Three Conventional Types with BRAF V600E Mutation

Multifocal papillary thyroid carcinoma (mPTC) comprises about 20-30% of PTC. In mPTC, individual tumor foci can be identical or frequently composed of different histological types including follicular, solid, tall-cell or conventional patterns. We report a case of mPTC consisting of one encapsulated follicular variant of papillary thyroid carcinoma (FVPTC) and three conventional PTCs in a 44-year-old woman. This case genetically demonstrates unique features including the simultaneous presence of the BRAF V600E (T1799A) mutation and the BRAF K601E (A1801G) mutation in conventional PTC and FVPTC, respectively.