Significance of lymph node metastasis in differentiated thyroid cancer

In search of new stratification strategies: tissue proteomic profiling of papillary thyroid microcarcinoma in patients with localized disease and lateral neck metastases

INTRODUCTION

Papillary thyroid carcinomas (PTC) are the most common thyroid malignancies that are often diagnosed as microcarcinomas when the tumor is less than one centimetre in diameter. Currently, there are no valid stratification strategies that would reliably assess the risk of lateral neck metastases and optimize surgical treatment.

MATERIALS AND METHODS

Aiming to find potential tissue biomarkers of metastatic potential, we conducted a cross-sectional proteomic pilot study on formalin-fixed paraffin-embedded tissues of metastatic (N = 10) and non-metastatic (N = 10) papillary thyroid microcarcinoma patients. Samples were analysed individually using liquid chromatography/mass spectrometry, and the differentially expressed proteins (DEP) were functionally annotated.

RESULTS

We identified five overexpressed DEPs in the metastatic group (EPB41L2, CSE1L, GLIPR2, FGA and FGG) with a known association to tumour biology. Using bioinformatic-based tools, we found markedly different profiles of significantly enriched biological processes between the two groups.

CONCLUSIONS

The identified DEPs might have a role as potential tissue biomarkers for PTC metastases. However, further prospective research is needed to confirm our findings.

Correlation between myoferlin expression and lymph node metastasis in papillary thyroid carcinoma

Background

Myoferlin is a multifunctional protein expressed in various normal and cancer cells, with novel oncogenic roles being newly discovered. Recently, correlations have been found between myoferlin expression and unfavorable prognosis in various carcinomas. This study investigated the prognostic role of myoferlin expression in papillary thyroid carcinoma (PTC), specifically that associated with nodal metastasis.

Methods

We collected clinicopathological data and PTC tissues from 116 patients who had been admitted to Gyeongsang National University Hospital in 2010. Immunohistochemical analysis was performed on surgical specimen-derived tissue microarray blocks. Myoferlin expression was graded, and the relationship between expression level and pathological features of tumors based on the American Joint Committee on Cancer staging system was evaluated.

Results

Of the 116 patient samples, 100 cases exhibited positive myoferlin expression. Higher grade of myoferlin expression was correlated with lower T category group (p = .010). Presence of lymph node metastasis was determined to be significantly correlated with low-grade myoferlin expression (p = .019), with no significant difference between pN1a and pN1b tumors.

Conclusions

Our study revealed an adverse correlation between myoferlin expression and pathological features of PTC, evidence of the potential prognostic role of myoferlin in PTC lymph node metastasis.

Is Gross Extrathyroidal Extension to Strap Muscles (T3b) Only a Risk Factor for Recurrence in Papillary Thyroid Carcinoma? A Propensity Score Matching Study

Simple Summary

In papillary thyroid carcinoma (PTC), staging classification of gross and minimal extrathyroidal extension (ETE) has been recently modified in the eighth edition of the American Joint Commission on Cancer/Union for International Cancer Control (AJCC/UICC) TNM staging system. In this study, we compared the clinicopathological characteristics and recurrence rates between minimal and gross ETE. No significant differences in the recurrence and disease-free survival rates were found between the two groups. Whether gross ETE invading strap muscles (T3b) only could be a risk factor for recurrence in PTC remains questionable.

Abstract

The presence of extrathyroidal extension (ETE) is associated with locoregional recurrence and distant metastases in papillary thyroid carcinoma (PTC). This study was designed to compare the recurrence risk between minimal ETE (mETE) and gross ETE (gETE) in patients with PTC using propensity score matching. In this study, 4452 patients with PTC who underwent thyroid surgery in a single center were retrospectively analyzed, and clinicopathological characteristics were compared according to the ETE status. Disease-free survival (DFS) and recurrence risk were compared between mETE and gETE after propensity score matching. The mean follow-up duration was 122.7 ± 22.5 months. In multivariate analysis, both mETE and gETE were not associated with recurrence risk before propensity score matching (p = 0.154 and p = 0.072, respectively). After propensity score matching, no significant difference in recurrence rates was observed between the two groups (p = 0.668). DFS of the gETE group did not significantly differ from that of the mETE group (log-rank p = 0.531). This study revealed that both mETE and gETE are not independent risk factors for the risk of recurrence in PTC. Our findings suggest that gETE invading strap muscles only might not be associated with worse oncological outcomes in PTC.

Modified risk stratification based on cervical lymph node metastases following lobectomy for papillary thyroid carcinoma

OBJECTIVE

Evidence for American Thyroid Association (ATA) risk stratification stems largely from studies involving patients undergoing total thyroidectomy. We aimed to assess the risk of recurrence according to the present ATA risk stratification system in patients who underwent lobectomy.

DESIGN

Retrospective cohort study.

PATIENTS

Patients who underwent thyroid lobectomy for 1-4 cm-sized papillary thyroid carcinoma (n = 571).

MEASUREMENTS

Disease-free survival (DFS) was compared according to the ATA risk stratification, and specific lymph node (LN) characteristics were evaluated to modify the ATA criteria with a higher predictability for recurrence.

RESULTS

Based on the ATA risk stratification, 439 patients (61.1%) were classified into intermediate- or high-risk group, and consideration for completion thyroidectomy is suggested by ATA guidelines for these patients. However, no significant differences were found in DFS among the low-, intermediate- and high-risk groups (P = .9). In contrast, when patients were stratified according solely to the LN criteria from the ATA risk stratification, only 127 patients (22.2%) had intermediate risk (intermediate-N1a) and exhibited significantly poorer DFS than those with N0 disease (P = .035). Modifying the intermediate-N1a criteria by adding the extranodal extension (ENE) status and omitting the clinical nodal disease enabled the subclassification of 19 patients (3%) with a high risk for recurrence.

CONCLUSIONS

The present study suggests that risk stratification based solely on LN metastases is more reasonable for predicting structural persistence/recurrence following lobectomy than that based on the overall ATA criteria. Considering the ENE status can assist in selecting patients with a high risk of recurrence to minimize further treatments.

An Update on the Risk of Lymph Node Metastasis for the Follicular Variant of Papillary Thyroid Carcinoma with the New Diagnostic Paradigm

Previous data has shown that the risk of nodal metastases is significantly greater for classical papillary thyroid carcinoma (PTC) as compared to the follicular variant (FVPTC). Given a recent change in diagnostic paradigm and definition of the noninvasive follicular thyroid neoplasm with papillary-like nuclear features (NIFTP) we intended to investigate if there remains a significant difference in nodal involvement between classical PTC and FVPTC. A 6-year retrospective review of all cases with FVPTC in the diagnostic line from the University of Utah/ARUP Laboratories was conducted. Two pathologists reviewed the remaining cases using the recently described histologic criteria of NIFTP to determine the total number the FVPTCs fitting the new classification paradigm. Histologic and clinical follow-up was tracked for all patients to determine the rate of nodal disease for all groups. 127 cases were identified using the above listed criteria. Forty-seven cases (37%) were classified as NIFTPs. None of the 47 patients had nodal disease either at the time of surgery or on follow-up. Twenty-eight cases met the current criteria for FVPTC (21%); of these 7/28 (25%) had evidence of nodal disease. By comparison, 17/45 (38%) of patients with mixed classical and FVPTC had nodal disease. Overall, there was no statistically significant difference in the risk of nodal metastasis between the pure FVPTC and mixed classical/FVPTC groups (p = 0.43). Our data indicates that implementing new definition for FVPTC will narrow the gap in the risk of nodal metastases between the classical PTC and FVPTC histologic subtypes.

Response to Treatment is Highly Predictable in cN0 Patients with Papillary Thyroid Carcinoma

BACKGROUND

While involvement of macrometastatic lymph nodes is a recognized independent predictor of an adverse course in papillary thyroid cancer (PTC) patients, the clinicopathological variables associated with disease persistence/recurrence in clinically node-negative (cN0) disease are not well defined. The indications for prophylactic central neck dissection (pCND) in this patient group remain unclear as well. We aim to investigate the risk factors associated with short- and long-term persistence/recurrence of PTC in patients with cN0 disease at presentation compared to patients with PTC and cervical lymph node involvement (N1) and the response to initial treatment in these subgroups of patients.

METHODS

Data were collected retrospectively for 392 consecutive patients with PTC, 223 with cN0 disease and 169 with N1 disease, who were treated and followed at a single tertiary medical center in which pCND is not routinely performed for PTC.

RESULTS

Compared to patients with N1 disease, patients with cN0 disease had significantly smaller tumors, lower rates of multifocality, and less extrathyroidal extension. Persistency rates at 1 year were 6.7 % in the cN0 group and 47 % in the N1 group, and at last follow-up, 3.6 and 33.5 %, respectively (p = 0.001 for both time points). Within the cN0 group, those with persistent disease at 1 year (n = 15) had significantly larger tumors and higher stimulated thyroglobulin. Only six had structural residual disease, four of them lymph node metastases. All patients with persistent disease were initially treated with total thyroidectomy and radioiodine. Recurrence occurred in only three patients. After 8.3 ± 3.8 years of follow-up, eight patients with cN0 had persistent disease, three of them biochemical. Higher American Joint Committee of Cancer stage and extrathyroidal extension were the only factors that predicted disease persistence at the last follow-up in this group.

CONCLUSIONS

Patients with cN0 PTC and no distant metastases are usually disease free after thyroidectomy with/without radioactive iodine and do not need further interventions. The initial staging in these patients is a valid prognostic factor for disease outcomes.

Predictive factors of right paraesophageal lymph node metastasis in papillary thyroid carcinoma: Single center experience and meta-analysis

BACKGROUND

We performed this retrospective study to identify predictors of right paraesophageal lymph node metastasis, and reviewed previous studies related to this topic.

METHODS

Between June 2005 and March 2015, 1107 patients were diagnosed with papillary thyroid carcinoma and underwent surgery at Pusan National University Hospital.

RESULTS

Right paraesophageal lymph node metastasis was observed in 171 (15.4%) patients. Multivariate analyses showed that the risk of right paraesophageal metastasis was significantly associated with tumor size, location, a higher number of metastatic central lymph nodes, and lateral lymph node metastasis. In a meta-analysis of the eligible studies, tumor size, number of metastatic central lymph nodes, and lateral lymph node metastasis showed significant relationships with the risk of right paraesophageal metastasis.

CONCLUSIONS

In patients with risk factors such as those identified in our study, the possibility of right paraesophageal metastasis should be kept in mind, and careful inspection and dissection are required.

Both F-18 FDG-avidity and Malignant Shape of Cervical Lymph Nodes on PET/CT after Total Thyroidectomy Predict Resistance to High-dose I-131 Therapy in Patients with Papillary Thyroid Cancer

Objective:

Resistance of metastatic lymph nodes (LNs) to high dose I-131 therapy is associated with high morbidity in patients with differentiated thyroid cancer. We evaluated the role of F-18 FDG PET/CT in the prediction of resistance to high dose I-131 therapy in patients with papillary thyroid cancer.

Methods:

The subjects were 307 patients who underwent total or near total thyroidectomy followed by high dose (5.55-6.66 GBq) I-131 therapy. We divided the patients into three subgroups by visual assessment of regional LNs: FDG-avid LNs with a malignant shape on CT (PET/CT-positive group), FDG-avid LNs with a benign shape on CT (PET/CT-intermediate group) and no FDG-avid lesion (PET/CT-negative group). We measured the maximum SUV (SUVmax) of FDG-avid LNs in each patient. The presence or absence of focal increased uptake of I-131 was evaluated by whole body scan (WBS), and was denoted as WBS-positive group or WBS-negative group, respectively. Resistance to therapy was defined as presence of thyroglobulin (Tg) in serum (Tg ≥1.0 ng/ml) 3-6 months after I-131 therapy. Univariate and multivariate analyses were performed to determine the relationship between resistance to I-131 therapy and various clinico-pathologic variables.

Results:

PET/CT-positive, intermediate, and negative groups included 20 (6.5%), 44 (14.3%) and 243 (79.2%) patients, respectively. The mean SUVmax was significantly higher in the PET/CT-positive group than that of the PET/CT-intermediate group (4.6 vs. 2.7, P <0.001). Univariate analysis revealed that the PET/CT-positive group (P <0.001), T2-4 stage (P <0.001), N1b stage (P = 0.001), lower dose (5.55 GBq) of I-131 (P <0.001), and the WBS-positive group (P = 0.029) were associated with resistance to therapy. In multivariate analysis, the PET/CT-positive group, lower dose of I-131, N1b stage, and T2-4 stage remained significant with odds ratios of 10.07 (P <0.001), 3.82 (P <0.001), 3.58 (P = 0.001), and 2.53 (P = 0.009), respectively.

Conclusion:

FDG-avidity and malignant shape of cervical LNs on pre-therapy FDG PET/CT were a strong risk factors predicting resistance to high dose I-131 therapy. A lower dose of administered I-131 (5.55 GBq) and more extensive tumors (T2-4 and N1b) were also associated with resistance to high dose I-131 therapy.

Nodal metastases in thyroid cancer: prognostic implications and management

The significance of cervical lymph node metastases in differentiated thyroid cancer has been controversial and continues to evolve. Current staging systems consider nodal metastases to confer a poorer prognosis, particularly in older patients. Increasingly, the literature suggests that characteristics of the metastatic lymph nodes such as size and number are also prognostic. There is a growing trend toward less aggressive treatment of low-volume nodal disease. The aim of this review is to summarize the current literature and discuss prognostic and management implications of lymph node metastases in differentiated thyroid cancer.

Ultrasound-based clinical prediction rule model for detecting papillary thyroid cancer in cervical lymph nodes: A pilot study

PURPOSE

To identify sonographic features of cervical lymph nodes (LNs) that are associated with papillary thyroid cancer (PTC) and to develop a prediction model for classifying nodes as metastatic or benign.

METHODS

This retrospective study included the records of postthyroidectomy patients with PTC who had undergone cervical ultrasound and LN biopsy. LN location, size, shape, hilum, echopattern, Doppler flow, and microcalcifications were assessed. Model selection was used to identify features associated with malignant LNs and to build a predictive, binary-outcome, generalized linear mixed model. A cross-validated receiver operating characteristic analysis was conducted to assess the accuracy of the model for classifying metastatic nodes.

RESULTS

We analyzed records from 71 LNs (23 metastatic) in 44 patients (16 with PTC). The predictive model included a nonhomogeneous echopattern (odds ratio [OR], 5.73; 95% confidence interval [CI], 1.07-30.74; p = 0.04), microcalcifications (OR, 4.91; 95% CI, 0.91-26.54; p = 0.06), and volume (OR, 2.57; 95% CI, 0.66-9.99; p = 0.16) as predictors. The model had an area under the curve of 0.74 (95% CI, 0.60-0.85), sensitivity of 65% (95% CI, 50% to 78%), and specificity of 85% (95% CI, 73% to 94%) at the Youden optimal cut point of 0.38.

CONCLUSIONS

Nonhomogeneous echopattern, microcalcifications, and node volume were predictive of malignant LNs in patients with PTC. A larger sample is needed to validate this model.

Prophylactic neck dissection for low-risk differentiated thyroid cancers: Risk-benefit analysis

BACKGROUND

The benefit of neck dissection is the subject of debate in differentiated thyroid cancer (DTC). We analyze the risk-benefit of neck dissection for low-risk DTC without detectable lymph nodes.

METHODS

We conducted a retrospective study from 1983 to 2003; which included 295 patients without detectable lymph nodes who were treated by thyroidectomy with (C+) or without (C-) neck dissection. All patients had iodine131 therapy. We compared the frequency of remission, disease progression, and permanent complications between groups.

RESULTS

Two hundred twelve patients comprised the C+ group, and 83 patients the C- group. Respectively for C+ versus C-, remission rates were 92% versus 89.2% (p = .40), and progressive disease observed was 3.3% versus 7.2% (p = .10). Permanent hypoparathyroidism occurred in 15.1% in C+ versus 3.6% in C- (p = .006).

CONCLUSION

The risk-benefit analysis of neck dissection in patients with low-risk DTC shows no benefit in terms of complete remission or occurrence of progression. However, risk of complications seems to be higher in patients with neck dissection. © 2016 Wiley Periodicals, Inc. Head Neck 38: 1091-1096, 2016.

Pathologic features of metastatic lymph nodes identified from prophylactic central neck dissection in patients with papillary thyroid carcinoma

The importance of pathologic features of metastatic lymph nodes (LNs), such as size, number, and extranodal extension, has been recently emphasized in patients with papillary thyroid carcinoma (PTC). We evaluated the characteristics of metastatic LNs identified after prophylactic central neck dissection (CND) in patients with PTC. We performed a retrospective review of 1,046 patients who underwent unilateral or bilateral thyroidectomy with ipsilateral prophylactic CND. We reviewed the characteristics of the metastatic LNs and analyzed their correlation to the clinicopathologic characteristics of the primary tumor. Cervical LN metastasis after prophylactic CND was identified in 280 out of 1046 patients (26.8 %). The size of metastatic foci (≥2 mm) was independently correlated with primary tumor size (≥1 cm) (p = 0.016, OR = 1.88). Primary tumor size (≥1 cm) was also correlated to the number of metastatic LNs (≥5) (p = 0.004, OR = 3.14) and extranodal extension (p = 0.021, OR = 2.41) in univariate analysis. The size of the primary tumor affects pathologic features of subclinical LN metastasis in patients with PTC. Patients with primary tumors ≥1 cm have an increased risk of larger LN metastases (≥2 mm), an increased number of LN metastases (≥5), and a higher incidence of ENE, which should be considered in decision for prophylactic CND.

Primary tumour characteristics predict the invasiveness of lymph node metastases in papillary thyroid carcinoma patients

OBJECTIVE

This study evaluated whether primary tumour characteristics are associated with specific features of metastatic lymph nodes in papillary thyroid carcinoma patients.

METHOD

A retrospective review of 411 patients with pathologically diagnosed cervical lymph node metastasis was conducted.

RESULTS

A metastatic lymph node focus size of at least 2 mm was independently associated with a primary tumour size of at least 1 cm (hazard ratio 1.962) and with male sex (hazard ratio 1.947). A number of at least five lymph node metastases was independently associated with a primary tumour size of at least 1 cm (hazard ratio 2.863), extrathyroidal extension (hazard ratio 1.737) and male sex (hazard ratio 1.689). Extranodal extension was independently associated with a primary tumour size of at least 1 cm (hazard ratio 2.288), extrathyroidal extension (2.201) and male sex (hazard ratio 1.733).

CONCLUSION

Primary papillary thyroid carcinoma characteristics are related to the pathological features of lymph node metastases.

A Meta-analysis of Central Lymph Node Metastasis for Predicting Lateral Involvement in Papillary Thyroid Carcinoma

OBJECTIVE

Whether central lymph node metastasis is a reliable indicator of lateral lymph node metastasis in papillary thyroid carcinoma remains obscure. To investigate the value of central lymph node metastasis for predicting lateral compartment involvement, we performed a meta-analysis of published studies.

DATA SOURCES

A systematic literature search of PubMed, EMBASE, and Chinese National Knowledge Infrastructure databases was completed, and the reference lists of the identified articles and prior relevant reviews were examined.

REVIEW METHODS

Two reviewers extracted data and assessed the quality of eligible studies independently. Odds ratios and 95% confidence intervals were pooled through a random effects meta-analysis model.

RESULTS

Twenty-one studies were eligible and further analyzed in this meta-analysis. The risk of lateral lymph node metastasis was significantly higher in the central lymph node-positive group than in the negative group (odds ratio = 7.64, 95% confidence interval: 5.59-10.44), with moderate heterogeneity across studies (P = .007, I(2) = 48.6%). Subgroup analyses and sensitivity analysis suggested that the results were consistent and credible. However, Begg's funnel plot and Egger linear regression test revealed a likelihood of publication bias (P = .000).

CONCLUSION

This meta-analysis suggests that central lymph node metastasis is valuable for predicting lateral compartment involvement in patients with papillary thyroid carcinoma. For those patients with central lymph node metastasis, additional attention should be paid to the lateral neck, as the risk of lateral lymph node metastasis was significantly higher in the central lymph node-positive group than in the negative group. Further studies regarding appropriate management for patients with high risk of lateral involvement are needed.

Central neck compartment dissection in papillary thyroid carcinoma: An update

Papillary thyroid carcinoma (PTC) is the most common thyroid malignancy, accounting for approximatley 90% of thyroid malignancies in areas of the world without deficit of Iodine. It’s universally accepted that total thyroidectomy is the minimal surgical treatment for patients with PTC higher than 1 cm. When a quality surgery is performed, the prognosis for PTC is excellent with 10 and 20-year overall survival rates around 90% and 85%, respectively. Lymph node metastases are very frequent in PTC, occurring in 50%-80% of PTC patients, the most of them being located in the central compartment of the neck (CCN) and with a high rate of occult or clinically undetectable disease. A lot of controversy exists regarding how to treat the central nodal compartment disease of PTC. The first problem is the lack of standardization of the terminology and concepts related to the CCN, which are clearly established and defined in this paper according to the most recent consensus documents of endocrine societies. This uniformity will provide a more consistent and clear communicaction between all the specialist involved in the treatment of PTC. CCN can be performed to treat patients with clinically detectable, radiologically suspected of intraoperative visualized nodal disease (this is defined as therapeutic) or when these findings are absent (also called prophylactic). Indicactions, advantages and disadvantages of both therapeutic and prophylactic CCN dissection are widely discussed and clear recommendations provided.

Radio-guided selective compartment neck dissection improves staging in papillary thyroid carcinoma: a prospective study on 345 patients with a 3-year follow-up

BACKGROUND

Prospective uncontrolled study to investigate in papillary thyroid carcinoma (PTC) patients: (1) Distribution of lymph node metastases within the neck compartments, (2) factors predicting lymph nodes metastases, and (3) disease recurrence after thyroidectomy associated with radio-guided selective compartment neck dissection (RSCND).

METHODS

We studied 345 consecutive PTC patients operated on between February 2004 and October 2011 at the S. Anna University Hospital, Ferrara (Italy). Patients with cervical lymph node metastases on preoperative ultrasonography and fine needle aspiration cytology were excluded. All patients underwent total thyroidectomy associated with SLN identification followed by RSCND in the SLN compartment, without SLN frozen section.

RESULTS

In patients with lymph node metastases, metastatic nodes were not in the central neck compartment in 22.6% of the cases. The presence of infiltrating or multifocal PTC was a predicting factor for lymph nodes metastases. The median follow-up was 35.5 months. RSCND was associated with a false-negative rate of 1.1%, a persistent disease rate of 0.6%, and a recurrent disease rate of 0.9%. The permanent dysphonia rate was 1.3%.

CONCLUSION

RSCND associated with total thyroidectomy may improve: (1) the locoregional lymph node staging, and (2) the identification of the site of lymphatic drainage within the neck compartments. Thus, considering the high false-negative rate of sentinel lymph node biopsy (SLNB), a radio-guided technique in PTC patients may guide the lymphadenectomy (ie, RSCND) to increase the metastatic yield and improve staging of the disease rather than avoid prophylactic lymphadenectomy (ie, SLNB).

A preoperative nomogram for the prediction of ipsilateral central compartment lymph node metastases in papillary thyroid cancer

BACKGROUND

Central compartment lymph node metastases in papillary thyroid carcinoma (PTC) are difficult to detect preoperatively, and the role of routine or prophylactic central compartment lymph node dissection (CLND) in managing PTC remains controversial. The aim of this project was to create a nomogram able to predict the occurrence of central compartment lymph node metastasis using readily available preoperative clinical characteristics.

METHODS

Records from patients undergoing total thyroidectomy and lymph node dissection for PTC in the period 1968-2012 were analyzed. Nodal status was based on results of serial hematoxylin and eosin (H&E) examination. Age, sex, tumor size, tumor site, and multifocality were included in a multivariable logistic regression model to predict lymph node metastasis. A coefficient-based nomogram was developed and validated using an external patient cohort.

RESULTS

The study population included 914 patients (80% females) with an average central compartment nodal yield of eight per patient. Central compartment lymph node metastases were present in 390 patients (42.7%). The variables with the strongest predictive value were age (p<0.001), male sex (p<0.001), increasing tumor size (p<0.001), and tumor multifocality (p<0.05). The nomogram had good discrimination with a concordance index of 76.4% [95% confidence interval 73.3-79.4], supported by an external validation point estimate of 61.5% [95% confidence interval 49.5-73.6]. An online calculator and smartphone application were developed for point of care use.

CONCLUSIONS

A validated nomogram utilizing readily available preoperative variables has been developed to give a predicted probability of central lymph node metastases in patients presenting with PTC. This nomogram may help guide surgical decision making in PTC.

Surgery of lymph nodes in papillary thyroid cancer

Optimal treatment for differentiated thyroid carcinoma is controversial with respect to the extent of thyroid resection, the extent and technique of nodal dissection and use of prophylactic radioiodine treatment. Postoperative complications, such as recurrent laryngeal nerve injury and definitive hypoparathyroidism, have carried great weight in the discussion regarding how radical the surgical treatment should be. The discussion of whether total thyroidectomy or lesser procedures should be the treatment for thyroid carcinomas has been protracted. Now, reasonable agreement exists that total thyroidectomy is the best treatment and the focus of the discussion has moved to the treatment of lymph nodes. At the time of diagnosis, node metastases are a common finding in patients with differentiated thyroid cancer, in particular papillary carcinoma. The argument supporting a radical approach to lymph node excision is that the presence of node metastases increases the recurrence rate. Advocates for the conservative approach believe that little association exists between node metastases and death from thyroid carcinoma. This paper reviews relevant medical literature published in the English language on surgery of lymph nodes in differentiated thyroid cancer with well-controlled trials. Searches were last updated in June 2006.

RAS mutations in thyroid cancer

In recent years, our understanding of the genetic alterations underlying thyroid oncogenesis has greatly expanded. The use of molecular markers, including RAS, in the management of thyroid carcinoma is also increasing. This review summarizes the current literature surrounding RAS and discusses its potential as a diagnostic and prognostic indicator in the management of thyroid cancer.

Impact of clinicopathologic factors on subclinical central lymph node metastasis in papillary thyroid microcarcinoma

PURPOSE

We evaluated whether the clinicopathological factors of papillary thyroid microcarcinoma (PTMC), especially tumoe size, are associated with subcinical central lymph node metastasis.

MATERIALS AND METHODS

A total of 160 patients diagnosed with PTMC who underwent total thyroidectomy with bilateral central lymph node dissection were enrolled in this study. All patients were clinically lymph node negative PTMC. Patients were divided into 2 groups according to the size of tumor (≤5 mm vs. >5 mm). Clinicopathologic risk factors for subclinical central lymph node metastasis were analyzed.

RESULTS

Subclinical central lymph node metastasis was detected in 61 (38.1%). Patients with tumors ≤5 mm had a lower frequency of extrathyroidal extension, multifocality and subclinical central lymph node metastasis. On multivariate analysis, only male and tumor size >5 mm were independent predictors of subclinical central lymph node metastasis; age, multifocality, bilaterality, extrathyroidal extension, lymphvascular invasion and lymphocytic thyroiditis were not.

CONCLUSION

In this study, male and tumor size >5 mm were two independent predictive factors for subclinical central lymph node metastasis in PTMC. These are easier factors to assess before surgery than other factors when planning the central lymph node dissection. However, further long-term follow-up studies are needed to confirm the prognostic significance of subclinical central lymph node metastasis in PTMC.

Management of well-differentiated thyroid cancer

This review provides an overview of current guideline recommendations for the clinical evaluation and surgical management of well-differentiated thyroid cancer, and further examines the evidence for controversial topics such as the minimum degree of primary resection, the role of elective central neck dissection, and the extent of lateral neck dissection. Well-differentiated thyroid cancer comprises the majority of thyroid cancers, about 90%, and includes both papillary and follicular carcinomas. Despite convergence of the medical community in establishing treatment guidelines under the American Thyroid Association, there still remain many areas of disagreement.

Extent of surgery for papillary thyroid cancer: preoperative imaging and role of prophylactic and therapeutic neck dissection

Papillary thyroid cancer (PTC) has an excellent prognosis, yet lymph node metastases are common. Most authors agree that central and/or lateral lymph node dissection should be undertaken in patients with abnormal lymph nodes detected on ultrasound, physical examination or intraoperative inspection. However the appropriate extent of prophylactic lymph node dissection for clinically node-negative patients remains the subject of controversy. There have been no randomized trials to date to offer guidance on this issue. The 2006 guidelines of the American Thyroid Association recommended consideration of prophylactic bilateral central lymph node dissection (CLND) for all patients undergoing thyroidectomy for PTC. However, the absence of compelling evidence for a benefit in terms of recurrence or survival, and the potential for increased morbidity, have led many, including our institution, to take an approach of selective central lymph node dissection. This approach is guided by the detection of abnormal lymph nodes on preoperative ultrasound, on physical examination, or during surgery. Postoperatively, ultrasound by an experienced ultrasonographer is the mainstay of evaluation for lymph node recurrence and is combined with monitoring of thyroglobulin and antithyroglobulin antibody levels. Reoperative lymph node dissection is typically undertaken upon detection and fine needle aspiration (FNA) of involved lymph nodes 0.8 cm or greater in size.

Right paraesophageal lymph node dissection in papillary thyroid carcinoma

BACKGROUND

This study was designed to identify the patients with papillary thyroid carcinoma (PTC) who would benefit from RPELN dissection.

SUMMARY BACKGROUND DATA

The value of the right paraesophageal lymph nodes (RPELNs), which are located posterior to the right recurrent laryngeal nerve, may be underestimated. Although the RPELNs are common sites of nodal recurrence, few related studies have been reported.

METHODS

We retrospectively reviewed the medical records of 369 patients (286 female, 83 male) who underwent total thyroidectomy (327 patients) or right lobectomy (42 patients) with therapeutic or prophylactic central lymph node dissection for primary PTC between August 2008 and January 2010 at the Department of Surgery, Samsung Medical Center.

RESULTS

Central lymph node (CLN) metastases were present in 51.2% (189 of 369) of the patients, and RPELN metastases were present in 12.2% (45 of 369) of the patients. The rate of RPELN metastasis was 19.6% (37 of 189) in patients with CLN metastases, but only 4.4% (8 of 180) in patients with no CLN metastases (P < .001). A univariate analysis revealed that RPELN metastasis was significantly correlated with the size of the tumor, the perithyroidal extent (capsular invasion), CLN metastasis, and lateral lymph node metastases. There were no significant differences in terms of gender, mean age, or number of tumors between groups. A multivariate analysis revealed that tumor size (>1 cm) and number of CLN metastases (≥ 3) were significantly correlated with RPELN metastasis.

CONCLUSIONS

RPELN dissection should be considered in patients with right thyroid cancer, tumors larger than 1 cm, or multiple CLN metastases.

Analysis of prognostic factors in patients with multiple recurrences of papillary thyroid carcinoma

PURPOSE

Numerous studies in the past have mentioned various factors that influence the recurrence of papillary thyroid carcinoma, including age, tumor size, advanced stage, extrathyroidal extension, and distant metastasis, and attempts have been made to classify the disease into low-risk and high-risk group based on these clinicopathological factors. However, there has been relatively scarce study on patients with multiple recurrent papillary thyroid carcinoma. This study analyzed the risk factors associated with such cases.

MATERIALS AND METHODS

This study investigated various clinicopathological factors of 416 patients who were diagnosed with papillary thyroid carcinoma and received primary surgery at Yonsei University Wonju College of Medicine, Department of Surgery, from January 1983 to December 2006 and were followed up until October 2010. An investigation of factors associated with patients showing multiple recurrences was made.

RESULTS

Patients were divided into 3 groups: group 1 (no recurrence, n=380), group 2 (1 recurrence only, n=21), and group 3 (multiple recurrences, n=15). The univariate analysis on risk factors revealed tumor size greater than 2 cm, multifocality, clinical apparent lymph node metastasis to be risk factors associated with multiple recurrences of papillary thyroid carcinoma. A multivariate analysis performed on variables selected from univariate analysis demonstrated no significant risk factor. The 10-year disease-specific survival for 3 different patient groups (group 1, 2, and 3) was 100%, 100%, and 83.1%, respectively, and patients in more clinically advanced group demonstrated poorer prognosis (p<0.001). The 10-year overall survival rate for the 3 patient groups was 93.9%, 100%, and 92%, respectively, and clinically advanced groups tended to show poorer overall survival rate as well (p=0.046).

DISCUSSION

A more aggressive and extensive surgery, as well as closer follow up, is to be required when operating on patients with tumor size greater than 2 cm, multifocality, clinical apparent lymph node metastasis. The use of imaging modalities, such as ultrasonography and PET-CT scan, may be desirable when monitoring such patients.

A scoring system for prediction of lateral neck node metastasis from papillary thyroid cancer

Lateral neck node metastasis is an important prognostic factor in thyroid carcinoma. We developed a scoring system for use in prediction of lateral neck node metastasis from papillary thyroid cancer. In this study, 161 consecutive patients were included in the training data set. This scoring system, named the Yonsei Estimated Value (YEV) for lymph node metastasis in papillary thyroid cancer, was developed on the basis of results from multivariate logistic regression analysis of preoperative clinical and radiologic data. Sixty eight consecutive patients were included for testing of the validity of the scoring system. The equation for prediction of lateral neck node metastasis was follows:YEV (Yonsei Estimated Value) = 1/(1+X)X = Exp (5.333-[0.902 × sex]+[0.036 × age]-[1.020 × tumor size]-[0.177 × lymph node size]-[0.032 × lymph node density])When the YEV was 0.3 or more, the probability of lateral neck node metastasis was 79.0%, with sensitivity of 76.3%, specificity of 69.8%, positive predictive value of 56.7%, and negative predictive value of 85.1% in the training set. When fine needle aspiration biopsy for suspicious lateral neck nodes is not possible, or the results are inadequate, our scoring system for prediction of lateral neck node metastasis can be helpful in optimization of the surgical extent for each patient.

Thyroid cancer and lymph node metastases

There is considerable controversy about the prognostic implications of lymph node metastases in patients with papillary thyroid cancer and whether patients with papillary thyroid cancer should have a prophylactic or selective central (level VI) neck dissection. Some experts report that a prophylactic ipsilateral neck dissection results in fewer patients having elevated thyroglobulin levels but others do not agree. A comprehensive review of the literature suggests that the presence of macroscopic metastases of papillary thyroid cancer in cervical lymph nodes results in a higher recurrence rate and increased death rate, especially in patients 45 years of age or older, whereas microscopic nodal metastases do not appear to adversely influence survival. Until more information is available we recommend preoperative ultrasonography and a selective ipsilateral neck dissection for patients with papillary thyroid cancer.

Analysis of the clinicopathologic features of papillary thyroid microcarcinoma based on 7-mm tumor size

BACKGROUND

We examined the clinicopathologic features of papillary thyroid microcarcinomas (PTMCs) measuring≤7 mm and compared them with those of PTMCs>7 mm.

METHODS

Between January 2007 and June 2009, a total of 275 patients with PTMCs underwent surgery. They were divided into two groups. Group I included patients with tumors≤7 mm, and group II included those with tumors>7 mm but ≤10 mm. We compared the two groups' clinicopathologic features.

RESULTS

Total thyroidectomy was more often performed in group II (p=0.003). Central lymph node metastases were identified in 30.6% of the patients in group I and in 47.8% of the patients in group II (p=0.005). A statistically significant difference between the two groups was also found for capsule invasion (p<0.0001), extrathyroidal extension (p=0.005), and lymphovascular invasion (p=0.025). On the multivariate analysis, central lymph node metastasis was the only independent factor associated with tumor size.

CONCLUSION

A PTMC≤7 mm is less likely to have aggressive features, including central lymph node metastasis, capsule invasion, extrathyroidal extension, and lymphovascular invasion, than a PTMC>7 mm. Because the aggressiveness of PTMC was found mainly in the patients with tumors >7 mm, we think that a cutoff value of 7 mm may be considered the threshold of aggressiveness of PTMCs.

Is thymectomy worthwhile in central lymph node dissection for differentiated thyroid cancer?

BACKGROUND

Clinical guidelines edited in 2006 by the American Thyroid Association (ATA) and stated in the European Thyroid Association Consensus (ETA) recommend routine central lymph node dissection (level VI neck dissection) in addition to thyroidectomy for the surgical treatment of differentiated thyroid cancer. This central dissection increases the incidence of postoperative hypocalcemia, which is related to the resection or devascularization of the inferior parathyroids together with bilateral thymectomy. Some authors perform unilateral thymectomy in order to minimize this complication. Our aim was to study the benefit/risk (incidence of thymic lymph node metastases versus postoperative hypocalcemia) of both procedures.

METHODS

We retrospectively reviewed the records of 138 patients who underwent total thyroidectomy with central neck lymph node dissection for differentiated thyroid cancer between 2004 and 2007. Bilateral thymectomy was performed in 45 patients (group 1, 15 males and 30 females) and unilateral thymectomy was performed in 93 patients (group 2, 27 males and 66 females). Forty-two papillary and 3 medullary cancers were found in group 1, and 75 papillary, 2 follicular, and 17 medullary cancers were found in group 2. The presence of thymic metastases at pathology and the occurrence of postoperative hypocalcemia were reviewed.

RESULTS

Two cases of papillary thymic metastases were found in group 1. These were lymph node micrometastases localized in the ipsilateral side of the primary tumor in both cases. Transient hypocalcemia was significantly more frequent (P < 0.001) in group 1 than in group 2: 16 patients (35.5%) versus 10 (10.7%). There was one case of permanent hypocalcemia in group 1 after the follow-up period.

CONCLUSIONS

Bilateral thymectomy risk outweighs any likely carcinologic benefit. We do not recommend routine bilateral thymectomy during central neck dissection for differentiated thyroid cancer.

Old and new insights in the treatment of thyroid carcinoma

Thyroid cancer is the endocrine tumor that bears the highest incidence with 33 550 new cases per year. It bears an excellent prognosis with a mortality of 1530 patients per year (Jemal et al.; 2007). We have been treating patients with thyroid carcinoma during many years without many innovations. Recently, we have assisted to the development of new agents for the treatment of this disease with unexpected good results. Here we present a review with the old and new methods for the treatment of this disease.

An Evaluation of Lymph Node Yield and Lymph Node Ratio in Well-Differentiated Thyroid Carcinoma

It is unknown whether the number of lymph nodes harvested (lymph node yield, LNY) or the proportion of metastatic lymph nodes resected (metastatic lymph node ratio, MLNR) influence survival in well-differentiated thyroid carcinoma (WDTC). We hypothesized that overall survival in WDTC is influenced by the LNY and MLNR. We used the Surveillance, Epidemiology, and End Results database to identify all patients with primary, nonmetastatic WDTC who underwent thyroidectomy with at least one lymph node removed between 1988 and 2004. Kaplan-Meier survival curves for LNY and MLNR were compared using the log rank test. Multivariate Cox proportional hazards models included tumor and patient-specific factors. WDTC patients that met entry criteria totaled 9926. In the univariate model, LNY and MLNR had a significant impact on survival ( P < 0.001). In multivariate analysis, increasing LNY was associated with poorer survival in all patients ( P = 0.001) and node-negative patients ( P = 0.03), but not for node-positive patients ( P = 0.27). MLNR did not influence survival in node-positive patients ( P = 0.84). Among patients with WDTC treated with thyroidectomy and lymphadenectomy, increasing LNY and MLNR were associated with decreased survival. The decrease in survival associated with increasing LNY, even in node-negative patients, indicates that nodal understaging is inconsequential to WDTC survival.

Adequate surgery for papillary thyroid cancer

Papillary thyroid cancer (PTC) is the most common type of thyroid cancer, occurring in about 80% of cases. Treatment consists ofsurgery, selective adjuvant radioiodine ablation, thyroid stimulating hormone suppression and surveillance. The extent of thyroidectomy and the extent of lymphadenectomy are controversial. Total or near-total thyroidectomy is recommended for the treatment of PTC, except those with papillary microcarcinoma (PTC < 1 cm) found incidentally after a thyroid lobectomy. This allows for treatment of possible multifocality (up to 8o% of cases), facilitates the use of radioiodine for remnant ablation and increases the sensitivity of thyroglobulin levels for surveillance, with complication rates comparable to lobectomy when done by experienced endocrine surgeons. A recent large database study supports this recommendation for PTCs > or = 1 cm; the optimal treatment of PTCs < 1 cm is still debatable, though many surgeons will perform total or near-total thyroidectomy for the reasons listed above. Contemporary series report lymph node metastases in up to 64% of patients, though their clinical significance is unclear. Reports are conflicting with respect to the impact of cervical nodal metastases on recurrence rates and survival, which are also affected by other patient, tumour and treatment-related factors. Therapeutic lymph node dissection is indicated for biopsy-proven nodal metastases. Prophylactic lateral neck lymphadenectomy is not recommended by experts in Europe and the USA. Prophylactic central neck lymphadenectomy is controversial, and may be advocated in selected patients while balancing the risks of the procedure.

Surgical management of well-differentiated thyroid cancer: state of the art

Nonmedullary well-differentiated thyroid cancer (WDTC) comprises a group of tumors including papillary thyroid carcinoma (PTC) and follicular thyroid carcinoma (FTC), with Hürthle cell carcinoma being a subtype of follicular carcinoma. This article reviews the epidemiology, pathogenesis, preoperative and diagnostic evaluation, imaging, and staging of WDTC. Different approaches to therapy and follow-up care are discussed. The prognosis for WDTC remains good and most patients can expect to be cured of their disease.

Ipsilateral versus bilateral central neck lymph node dissection in papillary thyroid carcinoma

OBJECTIVE

Many patients undergoing thyroidectomy for papillary thyroid carcinoma (PTC) have subclinical nodal disease at the time of surgery. Prophylactic bilateral central neck dissection (CND) is gaining acceptance in the treatment of PTC as studies have shown nodal disease increases the rate of local recurrence and may alter postsurgical radioactive iodine dosing. Given the potential complications of bilateral CND, we undertook a prospective study to determine the adequacy of prophylactic ipsilateral CND for PTC.

METHODS

A total of 116 patients with PTC underwent total thyroidectomy and routine prophylactic CND at a tertiary referral center. Of these, 45 had right and left central neck lymph node basins submitted separately for pathologic examination. We examined the laterality of positive lymph nodes based on tumor location and size.

RESULTS

Overall, positive lymph nodes were found in 45% of patients. Of the patients having a lateralized CND, 33% had ipsilateral positive nodes only, while 20% had bilateral positive nodes. None of the patients with tumor size <=1 cm had bilateral positive lymph nodes compared with 31% of patients with tumors >1 cm (P = 0.02). Multifocality did not affect lymph node metastasis in tumors <=1 cm. Parathyroids were found in the pathology specimen of 34% of patients, 40% had parathyroids autotransplanted, 47% had temporary hypocalcemia, and 0% had permanent hypocalcemia. Rates of temporary and permanent recurrent laryngeal nerve injury were 5% and 0% respectively.

CONCLUSIONS

Ipsilateral CND appears to be sufficient in patients with tumors <=1 cm. In tumors >1 cm, bilateral CND should be considered as these patients are more likely to have bilateral positive nodes. If tumor size is used as criteria for prophylactic CND, approximately one-third of patients can be spared a bilateral CND.

The role of lymphadenectomy in the management of papillary carcinoma of the thyroid

Impact of nodal involvement in papillary thyroid cancer remains controversial. The incidence of nodal metastases is high and the presence of involved nodes has a negative impact on recurrence and possibly on survival as well, particularly in older patients. The risk of nodal disease increases with age, tumor size, and BRAF oncogene expression. Most thyroid surgeons sample the ipsilateral central nodes as a minimum and clear the central compartment if there is gross adenopathy present. Lateral compartment neck dissection is reserved for patients with known metastatic disease. This article attempts to review the literature on surgery of lymph nodes in papillary thyroid cancer.

Predictive factors for central compartment lymph node metastasis in thyroid papillary microcarcinoma

OBJECTIVE

We examined the incidence of nodal involvement and attempted to determine the predictive factors for central compartment lymph node (LN) metastasis in thyroid papillary microcarcinoma (PMC).

STUDY DESIGN

Retrospective chart review.

METHODS

We undertook a retrospective study of 52 patients treated between January 2000 and December 2005 for PMC by total thyroidectomy and elective central compartment LN dissection with or without comprehensive lateral neck dissection (n = 9). There were 45 women and 7 men whose mean age was 47.6 +/- 11.5 years. The following criteria were used to study the predictive value of central compartment LN metastasis: sex, age, multifocality of the tumor, extracapsular spread (ECS), the involvement of the lateral neck LN, tumor size, and tumor location.

RESULTS

In 16 of 52 (31%) patients, central compartment LN metastasis was found. With use of univariate and multivariate analysis, ECS, lateral LN metastasis, and tumor size (>5 mm) were independent correlates of central compartment metastasis. Sex, age, multifocality, and tumor location were not associated with central compartment LN metastasis and did not significantly influence the predictive value of these variables.

CONCLUSIONS

We found a significant association among ECS, lateral LN metastasis, tumor size (>5 mm), and central compartment LN metastasis in patients with PMC. A prophylactic neck dissection of the central compartment should be considered particularly in patients with ECS of the tumors, metastatic LN in the lateral neck, and a greater than 5 mm tumor size.

Surgical approaches to thyroid tumors

This article includes discussions of the surgical approach to benign and malignant disease and the role of prophylactic thyroidectomy and nodal dissection for medullary thyroid cancer. The controversy regarding the extent of dissection for differentiated thyroid cancer and the role of lymph node dissection are reviewed also. A description of the authors' surgical technique for thyroidectomy is detailed. Finally, several emerging technologies are introduced.

Micrometastases in thyroid cancer. An important finding?

Differentiated thyroid cancer is a cancer with a good prognosis but the presence of lymph node metastases is associated with increased rates of loco-regional recurrence and in some reports decreased survival. This has led to an increased interest in the lymph node status with guidelines calling for routine central node dissection and increased interest in lateral compartment node sampling and sentinel node biopsy. We know from studies in regions where routine central and ipsilateral node dissection is the preferred surgical management of differentiated thyroid cancer that lymph node metastases are present in the majority of cases and that many of these are micrometastatic deposits. However, where routine node dissection is not performed recurrence rates are relatively low suggesting that not all micrometastatic disease progresses to a loco-regional recurrence or that the majority of disease is mopped up by adjuvant radioactive iodine. This review examines the available evidence for the significance of micrometastatic disease in differentiated thyroid cancer and suggests that it is probably of little clinical significance and does not warrant further aggressive surgical intervention. We would expect a conservative surgical approach combined with adjuvant radioactive iodine to lead to durable disease control.

Routine level VI lymph node dissection for papillary thyroid cancer: surgical technique

Total thyroidectomy is the treatment of choice for clinically significant papillary thyroid cancer (PTC); however, 10-15% develop palpable local recurrence in the cervical lymph nodes. Metastases in the cervical lymph nodes account for 75% of loco-regional recurrence and up to 50% of these patients eventually die of their disease. It is generally accepted that surgical excision of grossly involved lymph node disease should be carried out. The role of routine lymph node dissection, however, is greeted with far more controversy. Regional lymph node metastases have been shown to be associated with more frequent tumour recurrence. Not only is recurrence associated with increased disease-related mortality, but recent data have shown that the presence of involved lymph nodes is associated with adverse survival. Additionally, there have been significant changes to the way patients are managed after treatment for PTC in recent years. Surveillance previously relied on clinical assessment and radioiodine scans whereas now the use of serum thyroglobulin and high-resolution ultrasound are the standard as evidenced by recommendations by the American Thyroid Association. These techniques have greater sensitivity and subsequently lymph node metastases are being detected earlier and more frequently. This has led to a paradigm shift in the aims of treatment of PTC, from a focus on survival data to a focus on disease-free status. Routine central neck lymph node dissection can be carried out with no increased morbidity and can achieve lower 6-month stimulated thyroglobulin levels when compared with total thyroidectomy alone. Routine ipsilateral level VI lymph node dissection in addition to total thyroidectomy should be carried out for the management of clinically significant PTC.

Papillary thyroid microcarcinoma: incidence and prognostic factors

The objective of this study was to define the prognostic factors of papillary microcarcinoma of the thyroid (PMCT), and to analyse their epidemiologic and histopathologic characteristics. Our series included 57 patients diagnosed with PMCT between 1994 and 2003 among 944 patients who underwent thyroid surgery. All the surgical specimens were examined in the same department of pathology using the same technique. The prognostic factors were elaborated from the results of the histological examination. The epidemiological and histopathological characteristics were also evaluated. Two sub-groups were distinguished: patients with node disease and/or with metastasis (17 patients) and patients without node disease and metastasis (40 patients). The architecture of PMCT was papillary in 14% of cases, follicular in 35% of cases and mixed in 49% of cases, with no significant difference between any two groups. Histopathologic characteristics such as the vascular extension, infiltration into the adjacent parenchyma or in the thyroid capsule are all indicative of a poor prognosis. Two categories of PMCT, with and without the risk of metastatic spread, can be identified from these prognostic factors.

Lateral and Mediastinal Lymph Node Dissection in Differentiated Thyroid Carcinoma: Indications, Benefits, and Risks

BACKGROUND

There are 3 compartments of regional lymph nodes to which thyroid carcinoma metastasizes: central, lateral, and mediastinal compartments. The central compartment is the nearest to the thyroid and usually dissected routinely. However, the indication for dissection of the lateral and mediastinal compartments for differentiated thyroid carcinoma remains an open question.

METHODS

The indication for dissection of lateral and mediastinal compartments is evaluated based on previous reports, including those from our department.

RESULTS

There is nothing controversial about the indication for therapeutic lateral node dissection for tumors with clinically apparent lateral node metastasis. Such cases are more likely to show recurrence, especially in previously dissected compartments, and surgeons must perform dissection carefully. Although there are no randomized studies on the indication for prophylactic lateral node dissection, it is recommended for papillary carcinoma with aggressive characteristics such as large size and massive extrathyroid extension. Prophylactic mediastinal dissection via median sternotomy is not recommended.

CONCLUSIONS

Node dissection of the lateral and mediastinal compartments must be performed aggressively and radically to prevent recurrence in previously dissected regions.

Lymphadenectomy for papillary thyroid cancer: Changes in practice over four decades

AIMS

Lymphadenectomy in the management of papillary thyroid cancer (PTC) has evolved. The aim of this study was to examine the changing role of neck dissection as reflected in the practice of a large thyroid unit over four decades.

METHODS

A retrospective cohort study of patients that underwent primary thyroid surgery for papillary cancer in a single unit in the period 1958-2002. Nine 5-year periods were considered and the data relevant to the treatment of the regional lymph nodes reviewed.

RESULTS

Nine hundred patients with PTC underwent surgery between 1958 and 2002 of whom 32.7% underwent lymph node dissection (LND). The use of lymphadenectomy increased from 21.4% in 1958-1962 to 48.1% in 1998-2002 of which 84% underwent a selective lymph node dissection (SLND)-a dissection where the LND is determined by the extent of the disease encountered. The mean number of nodes removed during SLND was 12.6 (range 1-56) of which a mean of 3.1 (24.8%) (0-19) were involved by the disease. Cervical levels 6 and level 4 were those most frequently dissected. There was no statistically significant difference in the complication rates in patients undergoing neck dissection and those not.

CONCLUSION

The four decade experience reflects a move away from modified radical neck dissection and cherry picking towards SLND. Growing evidence suggests that lymphadenopathy in adult PTC is an adverse prognostic factor. SLND, a lymphadenectomy tailored to the extent of the disease process, is the coherent treatment for PTC since it serves the dual purpose of staging as well as control of local disease. This can be achieved with little morbidity when performed in a specialist centre.

Detection and surgical treatment of cervical lymph nodes in differentiated thyroid cancer

There is considerable controversy regarding the treatment of patients with cervical metastases from differentiated thyroid cancer. Most have papillary carcinoma and the main areas of contention relate to methods of assessment and staging, surgical management and mode of follow up. there is little evidence to support elective anatomical imaging with CT or MRI in those patients with suspected or proven malignancy at the primary site as indicated by fine needle aspiration cytology (FNAC) but who have no clinical evidence of nodal disease. The role of routine ultrasound (US) in the pre-operative assessment of suspected or known malignancy is developing but is largely unproven. When it is performed, high risk areas for metastatic neck disease (levels II-V) should be assessed. Suspicious nodes on US should be further evaluated by FNAC. Suspected or proven neck disease may be further assessed pre-operatively with CT or MRI and then treated surgically. Disease in the central compartment requires a total thyroidectomy and level VI central compartment neck dissection. Suspected or proven lateral compartment cancer should be treated by selective neck dissection (at least levels III, IV, and V) below the accessory nerve. There is no role for 'Berry picking' and clinically node negative high risk patients should have an elective central compartment level VI neck dissection. Sentinel node biopsy lays no role and neither does elective lateral compartment surgery in patients with no clinical or radiological evidence of disease. For follow up, US represents the most sensitive means of detecting neck recurrences and in the presence of an elevated serum thyroglobulin, imaging may also include whole body iodine-131 scanning and anatomical imaging with CT or MRI. The role of PET remains controversial but is likely to develop further as the technique becomes more widely available. In the future, the concentration of patients with this disease in large center can only improve the way we treat differentiated thyroid cancer.

Retrospective analysis of predictive factors for recurrence after curatively resected papillary thyroid carcinoma

PURPOSE

This retrospective study analyzes the predictive factors after curative surgery for papillary thyroid carcinoma (PTC).

METHODS

We analyzed 386 patients who underwent a curative operation for PTC in our hospital between 1977 and 1997, subject to the inclusion criteria.

RESULTS

According to univariate analysis, pathological lateral cervical lymph node involvement (P < 0.0001), dedifferentiation of the tumor (P < 0.002), male sex (P < 0.0001), a large tumor (P < 0.005), and an age of over 50 years (P < 0.05) were significant factors. Cox's proportional hazard model showed that a man (P < 0.05), aged over 50 years (P < 0.05), who had a large primary tumor (P < 0.05) with dedifferentiation (P < 0.05), and pathological lateral cervical lymph node metastasis (P < 0.005) was more likely to have recurrence of PTC.

CONCLUSIONS

Determining whether lymph node metastasis exists could be useful for predicting recurrence in patients who have undergone curative resection of PTC.