Distribution of lymph node micrometastasis in pN0 well-differentiated thyroid carcinoma

Identification of metastatic papillary thyroid carcinoma in FNA specimens using thyroid peroxidase immunohistochemistry

INTRODUCTION

We evaluated immunohistochemical staining for thyroid peroxidase (TPO), a glycoprotein found in the apical plasma membrane of thyroid follicular cells, as a marker for metastatic PTC in FNA samples and compared results with thyroglobulin (Tg) and thyroid transcription factor 1 (TTF1) staining.

METHODS

Cell block sections prepared from 100 FNA specimens were stained with a rabbit monoclonal antibody to TPO (EP159). The FNAs included 64 metastatic malignancies from non-thyroid primary sites, including 18 lung, and 36 cases of thyroid tumours (29 PTC, six cases of medullary thyroid carcinoma and one thyroid anaplastic carcinoma). Thyroid tumours were stained with TTF1 and Tg in addition to TPO. All cases of metastatic lung carcinoma also had TTF-1 staining results.

RESULTS

TPO staining was negative in all non-thyroid malignancies. Ninety percent (26/29) of PTC were positive. All positive cases showed strong cytoplasmic staining, although 54% (14/26) showed positivity in less than half of the cells. By comparison, Tg staining of TPC cases was present in 62% and TTF-1 in 100%. In addition to showing higher sensitivity, interpretation of staining results with TPO was generally easier with than Tg. All metastatic lung adenocarcinomas were positive for TTF-1 and TPO negative. The six medullary cancers showed positivity in 17%, 0% and 83% with TPO, Tg and TTF-1, respectively.

CONCLUSIONS

TPO (mAb EP159) may be a useful addition to immunohistochemical panels for FNA specimens where metastatic PTC is a consideration, particularly in cases where metastatic lung carcinoma features in the differential diagnosis.

Role of sentinel node in differentiated thyroid cancer: a prospective study comparing patent blue injection technique, lymphoscintigraphy and the combined technique

PURPOSE

The purpose of the present study was to evaluate the feasibility and reproducibility of the sentinel lymph node (SLNs) biopsy in differentiated thyroid cancer using patent blue injection, lymphoscintigraphy and the combined techniques.

METHODS

Between January 2011 and January 2013, 82 consecutive patients were enrolled in our prospective multicentre study. Inclusion criteria were 18 years of age, preoperative diagnosis of differentiated thyroid carcinoma, no evidence of lymph node enlargement and multifocal neoplasm. To investigate the benefits of each procedure, all patients underwent total thyroidectomy plus central compartment lymphadenectomy, and in all cases, the SLN was identified via one of three techniques using the same protocol.

RESULTS

Lymphoscintigraphy was used in five patients, patent blue injection was used in 40 patients, and a combined technique was used in 40 patients to identify sentinel lymph nodes (SLN). SLNs were identified in 61 cases. In the patent blue injection technique, the sensitivity, specificity and false negative rates were 88.9, 94.4 and 3.8%, respectively. In the lymphoscintigraphy technique, the percentages of sensitivity and specificity were 100%, and the percentage false negative was 0%. For the combined techniques, the corresponding values were, respectively, 69.2, 90, and 17.4%. Metastases were detected in nine cases of lateral-cervical nodes, ipsilateral tumour metastases were observed in eight cases, and contralateral tumour metastasis was observed in one case.

CONCLUSION

Additional well-designed randomized studies are needed to validate and further optimize the SLN biopsy in patients with differentiated thyroid cancer.

A Nomogram Based on the Characteristics of Metastatic Lymph Nodes to Predict Papillary Thyroid Carcinoma Recurrence

BACKGROUND

The extent of metastatic lymph node (LN) invasion was not considered in the postoperative stratification of the recurrence risk of papillary thyroid carcinoma (PTC) in the 2015 American Thyroid Association (ATA) guidelines, and the recommended risk stratification cannot be applied to individuals. A nomogram based on these risk factors was developed based on the risk factors to predict individual recurrence risk.

METHODS

Data from 1788 PTC patients at the West China Hospital and 306 cases from the Shang Jin Nan Fu Hospital between August 2013 and July 2015 were included in this study. The 1788 cases were randomized into two groups-the training set (896 cases) and the testing set (896 cases)-and 306 cases were used as the external evaluation set.

RESULTS

Univariate and multivariate analyses identified the following independent prognostic factors associated with recurrence in the three independent sets and the combined set (p < 0.01): LN invasion in the capsule or organ, more than five metastatic LNs, and a largest metastatic LN diameter >3 cm. Importantly, PTC patients showed significantly different recurrence rates depending on the extent of LN invasion in the three sets and in the combined set (p < 0.001). The nomogram was developed based on the risk factors in the training set and was validated in the independent testing and validation sets.

CONCLUSION

The largest LN metastasis diameter, number of metastatic LNs, and the extent of extranodal invasion had significant prognostic value for predicting the risk of recurrence. Based on the characteristics of the thyroidal PTC lesion and metastatic LNs, the nomogram showed good prediction of recurrence in individual PTC patients.

Clinicopathological significance of chemokine receptor CXCR4 expression in papillary thyroid carcinoma: a meta-analysis

INTRODUCTION

Emerging evidence indicates that C-X-C chemokine receptor type 4 (CXCR 4) is a candidate oncogene in several types of human tumors including papillary thyroid carcinoma (PTC). To investigate its expression impact on clinicopathological features, a meta-analysis was performed.

EVIDENCE ACQUISITION

A comprehensive search in the PubMed, Embase and The Cochrane Library (up to March 14, 2017) was performed for relevant studies using multiple search strategies. Methodological quality of the studies was also evaluated. Odds ratios (ORs) were calculated and summarized.

EVIDENCE SYNTHESIS

Final analysis was performed of 661 PTC patients from 8 eligible studies. The pooled OR indicated that CXCR4 expression was significantly higher in PTC than that in normal thyroid tissue and benign thyroid nodule (NTT/BTN) (OR=67.22, 95% CI: 32.85-137.55, P<0.00001). In subgroup analysis, CXCR4 expression was associated with age (OR=1.55, 95% CI: 1.02-2.34, P=0.04), lympaocytic thyroiditis (OR=1.68, 95% CI: 1.06-2.67, P=0.03); CXCR4 expression was not found to be associated with gender (OR=1.02, 95% CI: 0.66-1.58, P=0.93), multiple (OR=0.91, 95% CI: 0.55-1.53, P=0.73), lymph node metastatic (LNM) (OR=1.98, 95% CI: 0.88-4.47, P=0.10) and TNM stage (OR=2.00, 95% CI: 0.49-8.16, P=0.34). A sensitivity analysis found out the study by Zhu et al. which impacted the pooled OR, after removing this study, a positive and relatively stable result conformed that CXCR4 expression was associated to LNM.

CONCLUSIONS

The results of this meta-analysis suggest that CXCR4 expression is frequent and cancer-specific event in PTC.

Prognostic value of lymph node ratio in metastatic papillary thyroid carcinoma

Objective:

Cervical metastases in papillary thyroid carcinoma are associated with increased recurrence. However, their effect on survival remains controversial. This study evaluated literature on the prognostic value of lymph node ratio for loco-regional recurrence and survival in metastatic papillary thyroid carcinoma.

Methods:

The PubMed database was systematically searched using the terms ‘papillary thyroid carcinoma’ and ‘lymph node ratio’. Articles addressing the association between lymph node ratio and loco-regional recurrence or survival were identified.

Results:

Nine retrospective studies were included, comprising 12 400 post-thyroidectomy and neck dissection papillary thyroid carcinoma patients (median age, 48.6 years; 76 per cent females). Lymph node ratio was associated with worse recurrence-free survival in 60 and 75 per cent of studies investigating the effect of central compartment metastases and both central and lateral compartment metastases on recurrence-free survival, respectively. One large population-based study showed an association between lymph node ratio and disease-specific mortality in N1nodal disease, but failed to maintain the same association when N1bpatients were excluded.

Conclusion:

Regional lymph node ratio is an independent predictor for loco-regional recurrence in pathologically staged N1patients with papillary thyroid carcinoma. Patients with a high lymph node ratio should be closely followed up.

Significance of micrometastases in the calculation of the lymph node ratio for papillary thyroid cancer

Purpose

The lymph node ratio (LNR) is an important prognostic factor in papillary thyroid carcinoma (PTC), but micrometastases in cervical lymph nodes (LNs) are not of great clinical importance. In this study, we analyzed the accuracy of prediction of the prognosis depending on whether micrometastases were included in the number of metastatic LNs when calculating LNR.

Methods

The study included 353 PTC patients who underwent total thyroidectomy with neck LN dissection, and calculated LNR by 2 methods according to whether micrometastases were included in the number of metastatic LNs: Method 1 did not and method 2 did include. To compare the predictive values of LNR by the 2 methods, correlation coefficients and receiver operating characteristic (ROC) curves were analyzed.

Results

Positive correlations were found between LNR and preablation stimulated thyroglobulin (sTg) levels in both methods, but the correlation between method 1 LNR and preablation sTg level was significantly stronger than that for method 2 (Fisher z = 1.7, P = 0.045). The areas under these 2 independent ROC curves were analyzed; the prognostic efficacy of method 1 LNR was more accurate than that of method 2 LNR, and the difference was statistically significant (P = 0.0001).

Conclusion

Regional recurrence of PTC can be predicted more accurately by not including micrometastases in the number of metastatic LNs when calculating LNR.

A novel thyroid cancer nodal map classification system to facilitate nodal localization and surgical management: The A to D map

OBJECTIVES/HYPOTHESIS

To evaluate the effectiveness, reproducibility, and usability of our proposed nodal nomenclature and classification system employed for several years in our high-volume thyroid cancer unit, for the adequate localization and mapping of lymph nodes in thyroid cancer patients with extensive nodal disease.

STUDY DESIGN

Retrospective review.

METHODS

Thirty-three thyroid cancer patients with extensive nodal disease treated from January 2004 to May 2013 were included in our study. Preoperative ultrasound and computed tomography scans of these patients were reanalyzed by blinded radiologists to investigate the feasibility for the assignment of abnormal lymph nodes to compartments defined in our proposed nodal classification system and to identify areas of difficulty in the assignment.

RESULTS

Analysis of nodal localization revealed a discrepancy in compartment agreement between the two radiologists in the assignment of abnormal nodes in nine patients (9/33, 27%). In six patients (6/33, 18%), discrepancy existed in labeling paratracheal and pretracheal nodes. In three patients (3/33, 9%), disagreement arose in the classification of retrocarotid nodes into lateral versus central compartment. A further refinement of the definition of key borderline regions of the pretracheal versus paratracheal and retrocarotid regions of our classification improved the agreement and demonstrated a complete concordance (100%) amongst the reviewing radiologists.

CONCLUSIONS

The proposed nodal classification system, derived specifically for differentiated thyroid carcinoma, with readily identifiable anatomic boundaries on imaging and at surgery, facilitates communication among multidisciplinary physicians and aids in creating a uniform and reproducible radiographic nodal map to guide surgical therapy.

LEVEL OF EVIDENCE

4 Laryngoscope, 127:2429-2436, 2017.

Long-term survival in a patient with brain metastases of papillary thyroid carcinoma

We present the case of a 43-year-old woman who underwent total thyroidectomy with bilateral lymphadenectomy for a papillary thyroid carcinoma (PTC), solid variant (T4bN1bMx), with V600E BRAF mutation. After ablative therapy, she presented undetectable thyroglobulin (Tg) but progressively increasing anti-Tg antibodies (TgAbs). During follow-up, nodal, lung and brain metastases were identified. She was submitted to surgical excision of lung lesions, radiosurgery of brain metastases and five radioiodine treatments. The latest brain MRI showed no lesions, pulmonary CT showed stable micronodules and there was progressive reduction in TgAbs. This is a peculiar case of a PTC with lung and brain metastatic lesions detected through TgAbs. Initial histological and molecular study suggested a more aggressive clinical behaviour, which was eventually confirmed. Although PTC brain metastases are extremely rare and present poor prognosis, our patient presented a good response to treatment and longer survival than usually reported for similar cases.

2015 American Thyroid Association Management Guidelines for Adult Patients with Thyroid Nodules and Differentiated Thyroid Cancer: The American Thyroid Association Guidelines Task Force on Thyroid Nodules and Differentiated Thyroid Cancer

BACKGROUND

Thyroid nodules are a common clinical problem, and differentiated thyroid cancer is becoming increasingly prevalent. Since the American Thyroid Association's (ATA's) guidelines for the management of these disorders were revised in 2009, significant scientific advances have occurred in the field. The aim of these guidelines is to inform clinicians, patients, researchers, and health policy makers on published evidence relating to the diagnosis and management of thyroid nodules and differentiated thyroid cancer.

METHODS

The specific clinical questions addressed in these guidelines were based on prior versions of the guidelines, stakeholder input, and input of task force members. Task force panel members were educated on knowledge synthesis methods, including electronic database searching, review and selection of relevant citations, and critical appraisal of selected studies. Published English language articles on adults were eligible for inclusion. The American College of Physicians Guideline Grading System was used for critical appraisal of evidence and grading strength of recommendations for therapeutic interventions. We developed a similarly formatted system to appraise the quality of such studies and resultant recommendations. The guideline panel had complete editorial independence from the ATA. Competing interests of guideline task force members were regularly updated, managed, and communicated to the ATA and task force members.

RESULTS

The revised guidelines for the management of thyroid nodules include recommendations regarding initial evaluation, clinical and ultrasound criteria for fine-needle aspiration biopsy, interpretation of fine-needle aspiration biopsy results, use of molecular markers, and management of benign thyroid nodules. Recommendations regarding the initial management of thyroid cancer include those relating to screening for thyroid cancer, staging and risk assessment, surgical management, radioiodine remnant ablation and therapy, and thyrotropin suppression therapy using levothyroxine. Recommendations related to long-term management of differentiated thyroid cancer include those related to surveillance for recurrent disease using imaging and serum thyroglobulin, thyroid hormone therapy, management of recurrent and metastatic disease, consideration for clinical trials and targeted therapy, as well as directions for future research.

CONCLUSIONS

We have developed evidence-based recommendations to inform clinical decision-making in the management of thyroid nodules and differentiated thyroid cancer. They represent, in our opinion, contemporary optimal care for patients with these disorders.

Risk factors and indication for dissection of right paraesophageal lymph node metastasis in papillary thyroid carcinoma

BACKGROUND

Right paraesophageal lymph nodes (RPELNs) are located behind right recurrent laryngeal nerve which often ignored in central compartment lymph nodes (LNs) dissection of papillary thyroid carcinoma (PTC) patients. The aim of this study was to identify the risk factors for RPELN metastasis and indications for RPELN dissection.

METHODS

Medical record of 246 consecutive PTC patients (194 female, 52 male), who underwent total thyroidectomy (244 patients) or right lobectomy (2 patients) with central compartment LN dissection (13 ipsilateral and 233 bilateral), were reviewed. The RPELNs were kept separately during the operation. The clinical pathology data was collected and analyzed.

RESULTS

RPELN metastasis was confirmed in 33 patients (13.4%) and were discovered in 18.5% (31/168) of right lesion, 34.4% (31/90) of right central group LN (rCLN) metastasis, 33.3% (18/54) of lateral compartment LN (LLN) metastasis, 25.7% (9/35) of local recurrent patients respectively. The ultrasound suspected metastatic LNs, tumor diameter, tumor number, tumor location, and numbers of metastatic Delphian LNs, central group LNs (CLNs), rCLNs, and LLNs between patients with and without RPELN metastasis showed significant differences in univariate analysis (P < 0.05). In multivariate analysis, number of metastatic rCLNs (1-2: OR 13.6, 95% CI, 2.7-67.5; ≧3: OR39.4, 95% CI, 7.7-200.9), right side tumor (OR 6.4, 95% CI, 1.1-35.6), and three or more metastatic LLNs (OR 3.5, 95% CI, 1.2-10.2) were independent risk factors for RPELN metastasis.

CONCLUSIONS

PTC patients with right lobe lesions, especially with potential rCLN metastasis, are at considerable risk of RPELN metastasis. RPELN dissection should be considered in these patients.

Predictive factors and pattern of central lymph node metastasis in unilateral papillary thyroid carcinoma

OBJECTIVE

Prophylactic central neck dissection (CND) for papillary thyroid carcinoma (PTC) remains controversial. The aim of this study was to evaluate the patterns and predictive factors of central lymph node metastasis in cases of PTC that were clinically determined to be node negative.

METHODS

We studied 485 patients who have unilateral PTC without clinical lymph node metastasis and underwent total thyroidectomy and prophylactic bilateral CND from 2003 to 2012, retrospectively. The frequency, subsite and predictive factors of central lymph node metastasis were analyzed.

RESULTS

In total, 166 (32.4%) patients had occult central lymph node metastases. The most common subsite of central node metastases was the ipsilateral paratracheal lymph node (26.0%), followed by pretracheal (12.5%), prelaryngeal (5.0%), and contralateral paratracheal (3.9%) lymph nodes. The tumor size larger than 0.5cm (p=0.003), age under 45 (p<0.001) and extrathyroidal extension (p=0.028) were associated with ipsilateral central compartment metastasis in multivariate analysis. Contralateral central node metastasis was associated with tumor size >3cm, age under 45, and multifocality and ipsilateral central node metastasis in univariate analysis, but it was associated with only ipsilateral central node metastasis in multivariate analysis (p=0.001).

CONCLUSION

Prophylactic CND might be considered for PTC patients with large tumor size or extrathyroidal extension based on rates of lymph node metastasis. Unilateral CND might be appropriate as prophylactic CND due to the low metastatic rate to the contralateral paratracheal node.

Surgical morbidity of cervical lymphadenectomy for thyroid cancer: A retrospective cohort study over 25 years

INTRODUCTION

Prognosis of thyroid cancer is strictly related to loco-regional metastases. Cervical lymphadenectomy has a specific oncologic role but may lead to significant increase of morbidity. Aim of the study is the analysis of surgical morbidity in cervical lymphadenectomy for thyroid cancer.

METHODS

We retrospectively analyzed 1.765 thyroid cancers operated over a period of 25 years at S. Maria University Hospital, Terni, University of Perugia, Italy. Type of lymphadenectomy, histology and complications were analysed.

RESULTS

A prevalence of differentiated and medullary cancers was observed (respectively 88% and 7.2%). Central lymphadenectomy was carried out in 425 patients, lateral modified and radical lymphadenectomy respectively in 651 and 17 cases. Following central neck dissection we observed: bilateral and unilateral temporary recurrent nerves palsy respectively of 0.7% and 3.5%, unilateral permanent palsy in 1.6% of cases, temporary and permanent hypoparathyroidism respectively in 17.6% and 4.4%. After lateral neck dissection we observed: intra and post-operative haemorrhage respectively in 2% and 0.29%, respiratory distress in 0.29%, lesions of facial nerve in 0.44%, of vagus in 0.14%, of phrenic nerve in 0.14%, of hypoglossal nerve in 0.29%, of the accessory nerve, transient in 1.34% and permanent in 0.29%, permanent lesion of cervical plexus in 0.29%, salivary fistula in 0.14% and chylous fistula in 1.04% of patients. Student's t test was used to compare groups when appliable.

CONCLUSION

Central and lateral cervical lymph node dissection are associated to severe morbidity. Correct indication, surgical expertise, high volume of patients and early multidisciplinary management of complications is the key of an acceptable balance between oncologic benefits and surgical morbidity.

Pre-operative ultrasound diagnosis of nodal metastasis in papillary thyroid carcinoma patients according to nodal compartment

The aim of this study was to assess the accuracy of ultrasound (US) and individual US features in the diagnosis of nodal metastasis in patients with papillary thyroid carcinoma (PTC) with respect to nodal compartment. US diagnoses and individual US features of nodal metastases with respect to nodal compartment were investigated in 184 consecutive PTC patients who underwent pre-operative US. Histopathologic results were used as a reference standard. One hundred thirty-six of 368 (37.0%) central compartments contained one or more metastatic nodes, whereas 44 of 48 (91.7%) lateral compartments had one or more metastatic nodes. The malignancy rates of suspicious US diagnoses in the central and lateral compartments were 66.3% (53/80) and 93.3% (42/45), respectively. The central and lateral compartments differed significantly in nodal composition, echogenicity, calcification, shape, hilar echogenicity and vascularity. The accuracy of US in the diagnosis of nodal metastases from PTC was lower in the central compartment than in the lateral compartment.

Predictive factors of contralateral paratracheal lymph node metastasis in unilateral papillary thyroid carcinoma

BACKGROUND

Most of unilateral papillary thyroid carcinoma (PTC) metastasize to ipsilateral paratracheal lymph nodes (LNs) while some had contralateral paratracheal LN involved. The aim of this study was to analyze the predictive factors of contralateral paratracheal LN metastasis in unilateral PTC.

METHODS

Data on 332 patients with unilateral PTC who underwent total/near total thyroidectomy and bilateral central neck dissection (CND) with/without lateral neck dissection were collected retrospectively. Patients' demographics, the extent of surgeries, and the pathological status of LNs and primary tumor were analyzed.

RESULTS

A total of 332 patients (67 male and 265 female) were included. Contralateral paratracheal LN metastasis was found in 68 (68/332, 20.5%) patients. Tumor size (>1 cm) (P < .001), capsular/extracapsular invasion (P < .001), pretracheal/prelaryngeal LN metastasis (P < .001), lateral neck LN metastasis (P < .001) and ipsilateral paratracheal LN metastasis (P < .001) was significantly associated with contralateral paratracheal LN metastasis on univariate analysis. Multivariate analysis showed that tumor size (>1 cm) (P = .013), capsular/extracapsular invasion (P = .009), pretracheal/prelaryngeal LN metastasis (P = .021) and lateral neck LN metastasis (P = .002) were independent risk factors of contralateral paratracheal LN metastasis.

CONCLUSION

Primary tumor size >1 cm, capsular/extracapsular invasion, pretracheal/prelaryngeal LN metastasis and lateral neck LN metastasis are predictive factors of contralateral paratracheal LN metastasis in unilateral PTC, which may help to determine the optimal extent of CND in patients with PTC.

Recurrence of papillary thyroid cancer after optimized surgery

Recurrence of papillary thyroid cancer (PTC) after optimized surgery requires a full understanding of the disease, especially as it has changed in the last 15 years, what comprises optimized surgery, and the different types and implications of disease relapse that can be encountered. PTC has evolved to tumors that are much smaller than previously seen, largely due to various high quality imaging studies obtained for different reasons, but serendipitously identifying thyroid nodules that prove to be papillary thyroid microcarcinomas (PTMC). With rare exception, these cancers are cured by conservative surgery without additional therapy, and seldom result in recurrent disease. PTC is highly curable in 85% of cases because of its rather innocent biologic behavior. Therefore, the shift in emphasis from disease survival to recurrence is appropriate. As a result of three technologic advances-high-resolution ultrasound (US), recombinant TSH, and highly sensitive thyroglobulin (Tg)-disease relapse can be discovered when it is subclinical. Endocrinologists who largely control administration of radioactive iodine have used it to ablate barely detectable or even biochemically apparent disease, hoping to reduce recurrence and perhaps improve survival. Surgeons, in response to this new intense postoperative surveillance that has uncovered very small volume disease, have responded by utilizing US preoperatively to image this disease, and incorporated varying degrees of lymphadenectomy into their initial treatment algorithm. Bilateral thyroid resection-either total or near-total thyroidectomy-remains the standard for PTC >1 cm, although recent data has re-emphasized the value of unilateral lobectomy in treating even some PTC measuring 1-4 cm. Therapeutic lymphadenectomy has universal approval, but when lymph nodes in the central neck are not worrisome to the surgeon's intraoperative assessment, although that judgment in incorrect up to 50%, whether they should be excised has reached a central point of controversy. Disease relapse can occur individually or in combination of three different forms: lymph node metastasis (LNM), true soft tissue local recurrence, and distant disease. The latter two are worrisome for potentially life-threatening consequences whereas nodal metastases are often persistent from the initial operation, and mostly comprise a biologic nuisance rather than virulent disease. A moderate surgical approach of bilateral thyroid resection, with usual central neck nodal clearance, and lateral internal jugular lymphadenectomy for node-positive disease can be performed safely, and with about a 5% recurrence rate.

Predictive factors of central lymph node metastasis in papillary thyroid carcinoma

PURPOSE

The aim of this study was to evaluate the correlation between central lymph node (CLN) metastasis and clinicopathologic characteristics of papillary thyroid cancer (PTC). In addition, we investigated the incidence and risk factors for contralateral CLN metastasis in unilateral PTC. This study suggests the appropriate surgical extent for CLN dissection.

METHODS

A prospective study of 500 patients with PTC who underwent total thyroidectomy and prophylactic bilateral CLN dissection was conducted.

RESULTS

Of 500 patients, 255 had CLN metastases. The rate of CLN metastasis was considerably higher in cases of younger patients (<45 years old) (P < 0.001; odds ratio [OR], 2.357) and of a maximal tumor size greater than 1 cm (P < 0.001; OR, 3.165). Ipsilateral CLN metastasis was detected in 83.1% of cases (133/160) of unilateral PTC, only contralateral CLN metastases in 3.7% of cases (6/160), and bilateral CLN metastases in 13.1% of cases (21/160). The rate of contralateral CLN metastasis was considerably higher in cases of PTC with a large tumor size (≥1 cm) (P = 0.019; OR, 4.440) and with ipsilateral CLN metastasis (P = 0.047; OR, 2.613).

CONCLUSION

Younger age (<45 years old) and maximal tumor size greater than 1 cm were independent risk factors for CLN metastasis. Maximal tumor size greater than 1 cm and presence of ipsilateral CLN macrometastasis were independent risk factors for contralateral CLN metastasis. Therefore, both CLN dissections should be considered for unilateral PTC with a maximal tumor size greater than 1 cm or presence of ipsilateral CLN macrometastasis.

Lobectomy and prophylactic central neck dissection for papillary thyroid microcarcinoma: do involved lymph nodes mandate completion thyroidectomy?

BACKGROUND

The present study was designed to investigate the necessity of completion thyroidectomy for patients who underwent thyroid lobectomy for low-risk papillary thyroid microcarcinoma (PTMC) that was later pathologically diagnosed as central lymph node (CLN) metastasis.

METHODS

Between 1986 and 2001, we assessed 551 patients who underwent thyroidectomy with prophylactic ipsilateral central compartment neck dissection, and 409 patients were followed-up completely. Thyroid lobectomy were performed in 281 and 128 patients, respectively. The patients were divided into two groups according to CLN metastasis. Clinicopathological profiles and follow-up details were investigated by retrospective chart review.

RESULTS

The CLN-positive and -negative groups were comprised of 43 (15.2 %) and 238 patients (84.8 %), respectively. The mean ages of the two groups were not significantly different (p > 0.05). The mean tumor size of the CLN-positive group (6.8 mm) was significantly larger than that of the CLN-negative group (5.6 mm; p < 0.05). Microscopic capsular invasion was significantly higher in the CLN-positive group (51.2 vs. 23.9 %; p < 0.05). Overall, 21 patients (7.4 %, 21/281) experienced recurrence. Among these, 2 (4.7 %, 2/43) and 19 (8.0 %, 19/238) were in the CLN-positive and -negative groups, respectively. There was no significant correlation between CLN metastasis and tumor recurrence.

CONCLUSIONS

Postoperative recurrence was lower in the CLN-positive group, and there was no significant correlation between CLN metastasis and tumor recurrence. Our results suggest that it is not necessary to perform completion thyroidectomy for PTMC patients who have undergone thyroid lobectomy and who have been pathologically diagnosed with CLN metastasis.

Risk factor analysis for central nodal metastasis in papillary thyroid carcinoma

Lymph node involvement is associated with recurrence in papillary thyroid carcinoma (PTC). The central neck compartment (level VI) lymph nodes are at the greatest risk of metastases from PTC, but the role of central neck dissection (CND) remains controversial, particularly in PTC without clinical cervical lymph node metastasis (cN₀). The present study aimed to identify risk factors of central cervical nodal metastasis and the safety of CND in patients with cN₀ PTC. The current study retrospectively investigated 389 patients who had been followed up for 12.0–25.5 months after surgery, and were divided into positive or negative lymph node involvement groups according to the pathological results subsequent to this surgery. Univariate and multivariate analyses were used to study the risk factor of central node involvement. The mean tumor size was 0.71±0.35 cm (range, 0.1–2.0 cm). There was no significant difference in the rate of central lymph node involvement based on age (<45 or ≥45 years) or tumor focality (unifocal or multifocal). However, there were significant differences based on gender, extra-thyroid invasion and tumor size (P<0.05). The incidence of transient hypoparathyroidism and transient vocal cord paralysis following CND was 12.34 and 4.11%, respectively. No patient experienced permanent hypoparathyroidism or vocal cord paralysis. One patient (1/389; 0.23%) experienced disease recurrence during the follow-up. A larger tumor size and the male gender were significantly associated with the central nodal metastasis rate for cN₀ PTC with a tumor size of <2.0 cm. CND for cN₀ PTC patients was safe and the tumor-associated recurrence rate following CND plus total thyroidectomy was low. The present study suggests that CND should be conducted for male cN₀ PTC patients with a larger tumor size (≥0.5 cm).

Is malignant nodule topography an additional risk factor for metastatic disease in low-risk differentiated thyroid cancer?

BACKGROUND

Differentiated thyroid cancer (DTC) is the most common endocrine malignancy. In recent decades, the incidence has been increasing, largely due to increased detection of patients with low-risk or very low-risk DTC. According to European Thyroid Association and American Thyroid Association guidelines, radioiodine (RAI) thyroid remnant ablation is not indicated in very low-risk patients, while its role is still debated in low-risk patients. Accordingly, risk stratification of DTC patients is pivotal when deciding for or against RAI ablation. Presently, risk stratification is based on pTNM staging integrated with clinical parameters. The aim of our study was to evaluate the relationship between location of malignant thyroid nodules within the thyroid gland and the presence of loco-regional and/or distant metastases in patients with pT1a-pT1b DTCs.

METHODS

We reviewed the records of 246 patients (214 women, 32 men; female-to-male ratio 6.7:1) affected by unifocal DTC ≤ 2 cm, who had undergone RAI thyroid remnant ablation (activity ranged 555-4588 MBq) after levothyroxine withdrawal or after recombinant human TSH (rhTSH) stimulation. The majority of the patients (91.5%) were affected by papillary thyroid carcinoma.

RESULTS

Metastases were discovered by posttreatment whole-body scintigraphy in 29 out of 246 (11.8%) patients. In patients with metastases, malignant thyroid nodules were located in the right lobe (14/123, 11.4%), left lobe (7/95, 7.4%), and isthmus (8/27, 29.6%). The prevalence of metastases was significantly higher in patients with DTC located in the isthmus, compared to other sites (χ(2) = 9.6, p = 0.002).

CONCLUSIONS

Our data show for the first time that a location of a thyroid cancer in the isthmus is an additional risk factor for RAI avid metastatic disease in pT1a-pT1b DTC patients, regardless of the presence or absence of other risk factors.

Prophylactic level II neck dissection guided by frozen section for clinically node-negative papillary thyroid carcinoma: is it useful?

BACKGROUND

Prophylactic lateral neck dissection (PLND) is generally not performed for papillary thyroid carcinoma(PTC). When performed, occult metastases are found in upto 50 % of patients, although the incidence of occult level II nodes seems low. Our aim was to evaluate frozen section analysis-oriented elective level II PLND in patients with clinically node-negative (cN0) PTC.

METHODS

This retrospective study included patients with cN0 PTC treated with total thyroidectomy and prophylactic bilateral central and lateral neck dissection of ipsilateral levels III and IV. Frozen section analysis of PLND III and IV was performed. If positive, the PLND was extended to level II. We measured the accuracy of frozen section analysis, the incidence of occult level II metastasis, and oncologic outcomes.

RESULTS

A total of 295 patients were included. For frozen section analysis, the sensitivity was 71.0 %, specificity 99.6 %, positive predictive value 97.8 %, negative predictive value 92.4 %, overall accuracy 93.2 %. Definitive analysis found lateral node metastases in 63 of the 295(21 %) patients. Extension to level II was performed in 27 of 46 cases (59 %). Level II contained metastatic nodes in 12 of 27 (44 %) patients. There was no difference in total doses of 131I administered to patients with or without level II disease. Even when extension of PLND to level II was not performed, no cases of recurrent or persistent disease in level II occurred.

CONCLUSIONS

Frozen section analysis was highly accurate.The rate of occult metastases in level II was low. Detection of additional metastases in level II did not modify subsequent treatment or the rate of recurrence and is not useful for routine application.

Pathologic reporting of lymph node metastases in differentiated thyroid cancer: a call to action for the College of American Pathologists

Lymph nodes in differentiated thyroid cancer have many different histomorphologic features. The current AJCC staging system does not distinguish between different lymph node characteristics and is based entirely on the presence of metastatic disease to upstage pN0 to pN1. However, clinicians involved in the management of thyroid cancer recognize that there is a difference in the clinical significance of finding macroscopic versus microscopic nodes. There appears to be a difference in disease biology that allows lymph nodes to reach different sizes and to manifest disease extension outside the capsule, which has led clinicians, and even clinical practice guidelines, to stratify nodal metastases on the basis of these features. The inherent presumption is that all lymph node metastases in differentiated thyroid cancer do not have the same clinical significance with respect to the risk of recurrence and the risk of death. However, the College of American Pathology (CAP) has not mandated that pathologists include these findings as part of their standard reporting protocol in thyroid cancer. In order to arm clinicians with the tools to design clinical trials and to make important patient management decisions in the presence of lymph node metastases, it is imperative that the CAP adopt a strategy for more detailed reporting that is similar to the protocol currently utilized in breast cancer pathologic reporting.

Ultrasonographic findings relating to lymph node metastasis in single micropapillary thyroid cancer

Background

In thyroid cancer, preoperative ultrasonography (US) is performed to detect the primary tumor and lymph node metastasis (LNM), which are related to prognosis. This study examined the relationships between specific US findings and LNM in micropapillary thyroid cancer (MPTC).

Methods

Data on 220 patients with solitary MPTC who underwent total thyroidectomy and neck dissection between 2008 and 2009 were evaluated retrospectively. We classified the US findings according to the nature, shape, echogenicity, extent, margin, and calcification of the primary tumor and evaluated the correlations between these findings and those of LNM.

Results

Hypoechogenicity (odds ratio = 2.331, P = 0.025) and marked hypoechogenicity (OR = 4.032, P = 0.016) of MPTC were risk factors for central LNM. All of the patients with lateral cervical LNM showed hypoechogenicity or marked hypoechogenicity. Hypoechogenicity (odds ratio = 5.349, P = 0.047) and other types of calcification (odds ratio = 2.495, P = 0.010) were significant risk factors for lateral cervical LNM.

Conclusions

Specific sonographic findings (hypoechogenicity or marked hypoechogenicity, and calcification) suggest LNM.

A mathematical model using computed tomography for the diagnosis of metastatic central compartment lymph nodes in papillary thyroid carcinoma

OBJECTIVES

The purpose of this study was to establish a potential mathematical model for the diagnosis of the central compartment lymph node (LN) metastases of papillary thyroid carcinoma (PTC) using CT imaging.

METHODS

303 patients with PTC were enrolled. We determined the optimal cut-off points of LN size and nodal grouping by calculating the diagnostic value of each cut-off point. Then, calcification, cystic or necrotic change, abnormal enhancement, size, and nodal grouping were analysed by univariate and multivariate statistical methods. The mathematical model was obtained using binary logistic regression analysis, and a scoring system was developed for convenient use in clinical practice.

RESULTS

30 mm(2) for LNs area (size) and two LNs as the nodal grouping criterion had the best diagnostic value. The mathematical model was: p = e (y) /(1+ e (y) ), y = -0.670-0.087 × size + 1.010 × cystic or necrotic change + 1.371 × abnormal enhancement + 0.828 × nodal grouping + 0.909 × area. We assigned the value for cystic or necrotic change, abnormal enhancement, size and nodal grouping value as 25, 33, 20, and 22, respectively, yielding a scoring system.

CONCLUSIONS

This mathematical model has a high diagnostic value and is a convenient clinical tool.

KEY POINTS

• Papillary thyroid carcinoma has a relatively high rate of metastasis. • CT has unique advantages in evaluating the central compartment. • The mathematical model can improve the diagnosis of CT imaging. • Corresponding scoring system is a convenient clinical tool.

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).

New insights in risk stratification of differentiated thyroid cancer

PURPOSE OF REVIEW

Numerous staging and scoring systems exist for differentiated thyroid cancer (DTC), but all harbor limitations. This has prompted investigation for new factors with prognostic implications for DTC.

RECENT FINDINGS

Several new factors that may be involved in DTC risk stratification have emerged, such as thyroid stimulating hormone and molecular markers. In addition, others are controversial and being challenged, such as age, sex and lymph node involvement.

SUMMARY

The purpose of this review is to present recent updates in the literature on new potential risk stratification predictors for DTC.

Measuring Quality in Thyroid Cancer Surgery

Many of the surgical quality measures currently in use are not disease specific. For thyroid cancer, mortality and even recurrence are difficult to measure since mortality is rare and recurrence can take decades to occur. Therefore, there is a critical need for quality indicators in thyroid cancer surgery that are easily measured and disease specific. Here we will review recent research on two potential quality indicators in thyroid cancer surgery. The uptake percentage on postoperative radioactive iodine scans indicates the completeness of resection. Another measure, the lymph node ratio, is the proportion of metastatic nodes to the total number of nodes dissected. This serves as a more global measure of quality since it indicates not only the completeness of lymph node dissection but also the preoperative lymph node evaluation and decision-making. Together, these two quality measures offer a more accurate, disease-specific oncologic indicator of quality that can help guide quality assurance and improvement.

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.

Classification of locoregional lymph nodes in medullary and papillary thyroid cancer

BACKGROUND

Among the various thyroid malignancies, medullary and papillary thyroid carcinomas are characterized by predominant locoregional lymph node metastases that may cause morbidity and affect patient survival. Although lymph node metastases are frequently detected, the optimal strategy aiming at the removal of all tumor tissues while minimizing the associated surgical morbidity remains a matter of debate.

PURPOSE

A uniform consented terminology and classification is a precondition in order to compare results of the surgical treatment of thyroid carcinomas. While the broad distinction between central and lateral lymph node groups is generally accepted, the exact boundaries of these neck regions vary significantly in the literature. Four different classification systems are currently used. The classification system of the American Head and Neck Society and the corresponding classification system of the Union for International Cancer Control (UICC) are based on observations of squamous cell carcinomas and appointed to needs of head and neck surgeons. The classification of the Japanese Society for Thyroid Diseases and the compartment classification acknowledge the distinctive pattern of metastasis in thyroid carcinomas.

CONCLUSIONS

Comparison of four existing classification systems reveals underlying different treatment concepts. The compartment system meets the necessities of thyroid carcinomas and is used worldwide in studies describing the results of lymph node dissection. Therefore, the German Association of Endocrine Surgery has recommended using the latter system in their recently updated guidelines on thyroid carcinoma.

Different CXCR4 expression according to various histologic subtype of papillary thyroid carcinoma

Functional chemokine (C-X-C motif) receptor 4 (CXCR4) is well known to be over-expressed in papillary thyroid carcinoma (PTC). The aim of this study was to evaluate whether or not the expression of CXCR4 is different by histological subtypes of PTC and to elucidate the relationship between the expression of CXCR4 and clinicopathologic factors. CXCR4 expression in 127 PTC samples was assessed using immunohistochemical staining. The expression of CXCR4 showed different patterns according to the histological subtype of PTC (p < 0.001). A strong expression of CXCR4 was observed more frequently in the poorly differentiated region of PTC (81.0 %) than in classical PTC (50.0 %). Strong CXCR4 expression was less frequently shown in follicular variant (33.9 %) and in diffuse sclerosing variant (14.3 %) of PTC. CXCR4 expression showed a distinct pattern according to the histological subtype of PTC although not associated with other clinicopathological parameters.

Papillary thyroid microcarcinoma in Denmark 1996-2008: a national study of epidemiology and clinical significance

BACKGROUND

With an observed general rise in papillary thyroid carcinoma incidence, papillary microcarcinoma (PMC) is accordingly found more frequently and often incidentally by histological examination of surgical specimens from presumed benign thyroid disease. Only a few studies have specifically addressed the prognosis of incidentally found PMC, and they have been limited to retrospective single-center studies.

METHODS

This was a national, unselected, prospective cohort study of 406 papillary thyroid microcarcinoma patients diagnosed in Denmark from 1996 to 2008.

OBJECTIVE

The aim of this study was to evaluate incidence, outcome, and extent of necessary treatment, with special attention given to incidentally detected PMC.

RESULTS

Age-standardized ratios were found to increase from 0.35 per 100,000 per year in 1996 to 0.74 per 100,000 per year in 2008. A total of 240 out of 406 cases were found incidentally, and a significant rise in incidence was only found for the incidental cases. Median follow-up was 7.6 years for the incidental cases, and in this time span, five cases of recurrence and no deaths from thyroid cancer occurred. The five-year recurrence-free survival was 98.1%, and only occurrence of lymph-node metastasis was found to affect the recurrence rate. A total of 160 incidental cases were initially treated with lobectomy, and the incidence of recurrence was not significantly different in the cases receiving completion thyroidectomy.

CONCLUSION

The rising incidence of PMC in Denmark is explained by incidental cases. When the carcinoma is not the index tumor for surgery, this study implies that completion thyroidectomy does not improve prognosis.

Predictive factors for different subgroups of central lymph node metastasis in unilateral papillary thyroid carcinoma

AIMS

We aimed to investigate the incidence rates and risk factors for different subgroups of central neck lymph node (LN) metastasis (prelaryngeal, ipsilateral paratracheal, pretracheal, and contralateral paratracheal) in unilateral papillary thyroid carcinoma (PTC) patients with clinically negative neck nodes (cN0).

METHODS

We evaluated 184 patients from 2007 to 2009. The relationships between different subgroups of LN metastasis and clinical pathological factors were analyzed.

RESULTS

The incidence rates of different central LN metastases were diverse. Multivariate analysis indicated that lymphovascular invasion, perithyroidal invasion, and tumor size were risk factors for ipsilateral paratracheal central LN metastasis; tumor size was an independent risk factor for pretracheal central LN metastasis, and pretracheal or/and ipsilateral paratracheal central LN metastasis were risk factors for contralateral paratracheal central LN metastasis.

CONCLUSION

The extent of elective central LN dissection (CLND) should be decided based on different clinical pathological factors in cN0 PTC patients. Moreover, elective prelaryngeal CLND may be unnecessary.

Is minimal residual lymph node disease in papillary thyroid cancer of prognostic impact? An analysis of the epithelial cell adhesion molecule EpCAM in lymph nodes of 40 pN0 patients

This study was aimed to assess the extend of nodal microdissemination in patients with pN0 papillary thyroid carcinoma (PTC) using immunohistochemical analysis. In early stage PTC both, systematic lymphadenectomy as well as radio iodine treatment, aimed to eliminate occult nodal tumor involvement, are under controversial debate, since little is known about the extend of lymphatic microdissemination in these patients. Formalin embedded samples of the resected lymph nodes were systematically screened for the presence of disseminated tumor cells using immunohistochemistry (monoclonal antibody Ber-EP4). Clinical and histopathological parameters as well as the post-operative course were recorded. Survival data were analysed by the Kaplan-Meier method and the log rank test. Overall 321 lymph nodes of 40 patients were screened immunohistochemically. In 12.5% of the patients disseminated occult tumor cells were diagnosed. In addition to tumor resection 90% of the patients underwent adjuvant radio-iodine treatment. The mean observation period in our collective was 72 months. The detection of disseminated tumor cells did not correlate with clinicopathologic risk parameters and did not have significant influence on the prognosis of these patients. Immunohistochemical analysis enables the detection of disseminated tumor cells in patients with pN0 PTC. This finding seems to support the application of adjuvant radio iodine, even in early tumor stages.

Surgical management of the lateral neck compartment for metastatic thyroid cancer

PURPOSE OF REVIEW

The lateral neck compartment is the second most frequent target region for metastatic papillary thyroid cancer (PTC) and medullary thyroid cancer (MTC). Lateral lymph node metastases are associated with locoregional recurrence and, when they involve either side of the neck, with mediastinal and distant metastases.

RECENT FINDINGS

For tumors originating from the upper thyroid pole, the first nodal basin is not invariably the central compartment (as for primaries arising from the inferior thyroid pole) but often the upper part of the ipsilateral lateral compartment. Lymph node dissection of the first basin may differ depending on the location of the primary tumor. Involvement of the contralateral lateral compartment is seen in PTC with extensive central compartment involvement, and in MTC with preoperative basal calcitonin levels more than 200  pg/ml (normal limit <10  pg/ml).

SUMMARY

After lateral lymph node dissection for metastatic thyroid cancer, dysfunction of lateral neck nerves is fairly common. This observation underpins the importance of striking a balance between oncological benefit and surgical risk. Lateral lymph node dissection may be warranted for an upper thyroid pole primary, for a tumor with extensive involvement of the central compartment, and for an MTC with increased basal calcitonin level of 20-200  pg/ml (ipsilateral dissection) or more than 200  pg/ml (bilateral dissection).

Pitfalls in the staging of cancer of thyroid

Thyroid cancer includes several neoplasms originating from the thyroid gland-from indolent and curable histologies of differentiated thyroid carcinoma to aggressive anaplastic thyroid carcinoma. Differentiation of thyroid nodules is problematic on CT and MR imaging unless there is evidence of extrathyroidal extension. Evaluation of regional lymph nodes is often performed clinically or with ultrasound. The retropharyngeal and mediastinal lymph nodes are better evaluated by CT and MR imaging. Nuclear scintigraphy is useful for staging and treatment of distant metastasis in differentiated thyroid carcinoma. PET may have a role in aggressive cancers. Accurate staging affects surgical management and subsequent therapy.

Papillary thyroid carcinoma nodal surgery directed by a preoperative radiographic map utilizing CT scan and ultrasound in all primary and reoperative patients

BACKGROUND

To study the diagnostic accuracy of physical examination (PE), ultrasonography (US), contrastenhanced computed tomography (CT) and in preoperative detection of macroscopic nodal metastasis in primary/recurrent papillary thyroid carcinoma (PTC) patients to determine if the routine addition of CT would be beneficial in accurate preoperative lymph-node surgery planning.

METHODS

In a tertiary center prospective study, 162 PTC patients underwent preoperative lymph-node evaluation by PE, US, and CT. Sensitivity, specificity, positive/negative predictive value (PPV/NPV) of each nodal detection technique were calculated in central/lateral cervical compartments. The gold standard for diagnostic-accuracy was surgical pathology.

RESULTS

In patients undergoing primary (Group I)/revision (Group II) surgical treatment for PTC, combined US/CT yielded significantly higher sensitivity for macroscopic lymph-node detection in both lateral and central neck, most marked in Group I-central compartment.

CONCLUSIONS

Combined preoperative US/CT provides reliable, objective, preoperative macroscopic nodal metastasis map to design rational nodal surgery in primary/revision PTC patients.

German Association of Endocrine Surgeons practice guideline for the surgical management of malignant thyroid tumors

INTRODUCTION

Over the past years, the incidence of thyroid cancer has surged not only in Germany but also in other countries of the Western hemisphere. This surge was first and foremost due to an increase of prognostically favorable ("low risk") papillary thyroid microcarcinomas, for which limited surgical procedures are often sufficient without loss of oncological benefit. These developments called for an update of the previous practice guideline to detail the surgical treatment options that are available for the various disease entities and tumor stages.

METHODS

The present German Association of Endocrine Surgeons practice guideline was developed on the basis of clinical evidence considering current national and international treatment recommendations through a formal expert consensus process in collaboration with the German Societies of General and Visceral Surgery, Endocrinology, Nuclear Medicine, Pathology, Radiooncology, Oncological Hematology, and a German thyroid cancer patient support organization.

RESULTS

The practice guideline for the surgical management of malignant thyroid tumors includes recommendations regarding preoperative workup; classification of locoregional nodes and terminology of surgical procedures; frequency, clinical, and histopathological features of occult and clinically apparent papillary, follicular, poorly differentiated, undifferentiated, and sporadic and hereditary medullary thyroid cancers, thyroid lymphoma and thyroid metastases from primaries outside the thyroid gland; extent of thyroidectomy; extent of lymph node dissection; aerodigestive tract resection; postoperative follow-up and surgery for recurrence and distant metastases.

CONCLUSION

These evidence-based recommendations for surgical therapy reflect various "treatment corridors" that are best discussed within multidisciplinary teams and the patient considering tumor type, stage, progression, and inherent surgical risk.

Hemithyroidectomy increases the risk of disease recurrence in patients with ipsilateral multifocal papillary thyroid carcinoma

Papillary thyroid carcinoma (PTC) is often clinically multifocal. In this study, the clinicopathological characteristics of a total of 347 PTC patients treated between 2006 and 2007 were investigated in order to assess the risk factors for tumor recurrence in patients with multifocal PTC. Of all the PTC cases reviewed, 35 (10%) were categorized as multifocal PTC. Patients with multifocal PTC were significantly more likely to have extrathyroidal extension, lymph node metastases and disease recurrence (P<0.05). Hemithyroidectomy resulted in a significantly higher incidence of tumor recurrence in patients with ipsilateral multifocal PTC compared with unifocal PTC patients (P<0.01). In conclusion, hemithyroidectomy was associated with tumor recurrence in patients with ipsilateral multifocal PTC but not those with unifocal PTC. Hemithyroidectomy should only be carried out after careful deliberation when involving patients with ipsilateral multifocal PTC.

Lymph node ratio predicts recurrence in papillary thyroid cancer

BACKGROUND

Lymph node metastasis occurs in 20%-50% of patients presenting for initial treatment of papillary thyroid cancer (PTC). The significance of lymph node metastases remains controversial, and the aim of this study is to determine how the lymph node ratio (LNR) may predict the likelihood of disease recurrence.

METHODS

We conducted a retrospective review of patients undergoing total thyroidectomy for PTC at our institution from 2005 to 2010. A total LNR (positive nodes to total nodes) and central lymph node ratio (cLNR) was calculated. Regression was used to determine a threshold LNR that best predicted recurrence. Multivariate logistic regression then determined the influence of LNR on recurrence while accounting for other known predictors of recurrence. Kaplan-Meier analysis and the log-rank test were used to compare differences in disease-free survival.

RESULTS

Of the 217 patients undergoing total thyroidectomy for PTC, 69 patients had concomitant neck dissections. Sixteen (23.2%) patients developed disease recurrence. When disease-free survival functions were compared, we found that patients with a total LNR ≥0.7 (p < .01) or a cLNR ≥0.86 (p = .04) had significantly worse disease-free survival rates than patients with ratios below these threshold values. Considering other known predictors of recurrence, we found that LNR was significantly associated with recurrence (odds ratio: 19.5, 95% confidence interval: 4.1-22.9; p < .01).

CONCLUSIONS

Elevated total LNR and cLNR are strongly associated with recurrence of PTC after initial operation. LNR in PTC is a tool that can be used to determine the likelihood of the patient developing recurrent disease and inform postoperative follow-up.

Impact of lymph node ratio on survival in papillary thyroid cancer

BACKGROUND

In papillary thyroid cancer, the role of lymph node dissection remains controversial, and staging systems consider metastatic lymph nodes as a binary entity. The purpose of this study was to determine a threshold lymph node ratio (LNR) that impacted disease-specific mortality (DSM).

METHODS

We utilized the surveillance, epidemiology, and end results (SEER) database to analyze adult patients who underwent thyroidectomy with lymph node dissection. A LNR (metastatic lymph nodes to total lymph nodes) was calculated after eliminating patients with less than three nodes collected. Kaplan-Meier estimates for DSM were plotted for LNRs and compared by the log rank test. The Cox proportional hazards model was used to evaluate LNR with other known clinical and pathologic determinants of prognosis.

RESULTS

A total of 10,955 cases contained data on lymph nodes. Median follow-up time was 25 months (range 0-59 months), and the mean LNR was 0.28 ± 0.37. After comparing Kaplan-Meier survival estimates and overall DSM rates, we found that a LNR ≥0.42 best divided those with lymph node metastasis based on DSM (p < 0.01). Those with a LNR ≥0.42 experienced a DSM rate of 1.72 % while those with a LNR <0.42 had a DSM rate of 0.65 % (p < 0.01). In addition, patients with a LNR ≥0.42 experienced a 77 % higher DSM rate compared to those with metastatic lymph nodes as a whole. When considered with other known determinants of prognosis, we found that LNR was strongly associated with DSM (hazard ratio 4.33, 95 % confidence interval 1.68-11.18, p < 0.01).

CONCLUSIONS

LNR is a strong determinant of DSM, and a threshold LNR of 0.42 can be used to risk-stratify patients with metastatic lymph nodes.

The prognostic significance of nodal metastases from papillary thyroid carcinoma can be stratified based on the size and number of metastatic lymph nodes, as well as the presence of extranodal extension

BACKGROUND

Ultrasound and prophylactic dissections have facilitated identification of small-volume cervical lymph node (LN) metastases in patients with papillary thyroid carcinoma (PTC). Since most staging systems do not stratify risk based on size or number of LN metastases, even a single-microscopic LN metastasis can upstage a patient with low-risk papillary thyroid microcarcinoma (PMC) to an intermediate risk of recurrence in the American Thyroid Association (ATA) system and to an increased risk of death in the American Joint Committee on Cancer (AJCC) staging system (stage III if the metastatic node is in the central neck or stage IVA if the microscopic LN metastasis is identified in the lateral neck). Such microscopic upstaging may lead to potentially unnecessary or additional treatments and follow-up studies. The goal of this review is to determine if the literature supports the concept that specific characteristics (clinically apparent size, number, and extranodal extension) of LN metastases can be used to stratify the risk of recurrence in PTC.

SUMMARY

In patients with pathological proven cervical LN metastases (pathological N1 disease; pN1), the median risk of loco-regional LN recurrence varies markedly by clinical staging, with recurrence rates for patients who are initially clinically N0 (clinical N0 disease; cN0) of 2% (range 0%-9%) versus rates of recurrence for patients who are initially clinically N-positive (clinical N1 disease; cN1) of 22% (range 10%-42%). Furthermore, the median risk of recurrence in pN1 patients varies markedly by the number of positive nodes, <5 nodes (4%, range 3%-8%) vs. >5 nodes (19%, range 7%-21%). Additionally, the presence of extranodal extension was associated with a median risk of recurrence of 24% (range 15%-32%) and possibly a worse disease-specific survival.

CONCLUSION

Our previous paradigm assigned the same magnitude of risk for all patients with N1 disease. However, small-volume subclinical microscopic N1 disease clearly conveys a much smaller risk of recurrence than large-volume, macroscopic clinically apparent loco-regional metastases. Armed with this information, clinicians will be better able to tailor initial treatment and follow-up recommendations. Implications of N1 stratification for PTC into small-volume microscopic disease versus clinically apparent macroscopic disease importantly relate to issues of prophylactic neck dissection utility, need for pathologic nodal size description, and suggest potential modifications to the AJCC TNM (tumor, nodal disease, and distant metastasis) and ATA risk recurrence staging systems.