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

Optimization of staging of the neck with prophylactic central and lateral neck dissection for papillary thyroid carcinoma

OBJECTIVE

To analyze the yield and rate of node metastases (pN1) for prophylactic central (CND) and lateral neck dissection (LND) for papillary thyroid carcinoma, the risk factors for pN1, and outcomes.

BACKGROUND

Prophylactic CND and LND are not routinely employed. Adjuvant radioiodine treatment may be modulated, however, by surgical staging of the neck.

METHODS

Retrospective study, consecutive patients ultrasonographically classified cN0 treated with prophylactic CND, and lateral LND (levels III and IV). The number of nodes was resected and the incidence of pN1 was recorded.

RESULTS

For 317 patients (254 women, mean age 44 years, mean tumor size 17 mm), the number of lymph nodes was 5 for unilateral CND, 9 for bilateral CND, and 12 for LND. pN1 stage was 42% overall: 23% for unilateral CND, 39% for bilateral CND, and 23% for LND (median number of metastatic nodes = 2 for each). Fifty-five percent of the patients staged pN1 had metastatic nodes in the lateral neck. Ten percent had more than 10 metastatic nodes and/or more than 3 nodes with extra capsular spread. pN1 was correlated with tumor size (P = 0.0025), extrathyroidal tumor extension (P < 0.0001), male sex (P = 0.0006), and age younger than 45 years (P = 0.0003). Permanent hypoparathyroidism and unintentional recurrent nerve paralysis occurred in 2 cases each. Patients staged pN0 received less radioiodine than patients staged pN1 (median 30 vs 100 mCi, P < 0.0001).

CONCLUSIONS

For staging, bilateral prophylactic CND is preferable to unilateral CND. Prophylactic CND with LND optimizes staging providing a basis for a personalized approach for adjuvant radioiodine.

Total versus hemithyroidectomy for microscopic papillary thyroid cancer

BACKGROUND

No increased mortality has been reported in patients with thyroid papillary microcarcinoma (PMC); however, neck recurrences and distant metastases have been described. In this study, we compare patients' outcomes after total thyroidectomy vs hemithyroidectomy for treatment of thyroid PMC.

METHODS

Two hundred and ninety-three patients from two major medical centers in Israel were included. The mean follow-up period was 7.2±6.8 yr.

RESULTS

Total thyroidectomy was performed in 214 patients and hemithyroidectomy in 79 patients. Mean tumor size was 6.3±3 mm. Lymph-node (LN) metastases and extraglandular extension were more frequent in the total thyroidectomy group than in the hemithyroidectomy group, 24.8% vs 1.3% (p<0.001) and 11.7% vs 3.8% (p=0.042), respectively. The cumulative incidence of recurrence at the end of follow-up was 13.2% in the total thyroidectomy group and 14.3% in the hemithyroidectomy group (p=ns). The incidence of recurrence was higher in patients with LN involvement in both groups. Considering low risk patients only (monofocal tumors, no LN involvement, no extraglandular extension; no.=63 in the total thyroidectomy group vs no.=60 in the hemithyroidectomy group) neck recurrence was found in 10% of patients in the hemithyroidectomy group but none in the total thyroidectomy group. In the hemithyroidectomy group, all locoregional recurrences were diagnosed using ultrasonography, compared to 47.6% in the total thyroidectomy group.

CONCLUSION

For patients with monofocal disease within the thyroid gland and no LN involvement, hemithyroidectomy can be considered an option, bearing in mind a higher risk for recurrence. For all other patients with PMC, we propose total thyroidectomy as initial treatment.

The efficacy of lateral neck sentinel lymph node biopsy in papillary thyroid carcinoma

BACKGROUND

Although occult lymph node metastasis to the lateral neck compartment is common in papillary thyroid carcinoma, the incidence and patterns of lateral neck node metastasis in papillary carcinoma are not known. We hypothesized that sentinel lymph node biopsy (SLNB) with radioisotope in the detection of occult lateral neck node metastasis would be useful in characterizing metastasis in papillary carcinoma.

METHODS

Ninety-four patients with papillary thyroid carcinoma were included from June 2009 to March 2010 for lateral neck SLNB. Preoperative lymphoscintigraphy was obtained after intratumoral injection of a (99m)Tc-tin colloid under ultrasound guidance. Total thyroidectomy or lobectomy preceded SLN detection to avoid radioactivity interference with the primary tumor, after which SLNB was performed in the lateral neck nodes. In the cases where metastasis was detected in SLNs upon frozen biopsy, an immediate modified radical neck node dissection was performed.

RESULTS

A total of 174 SLNs were identified in 60 patients (63.8%). The identification rate of the SLNs with isotope increased with time. Sentinel lymph node metastasis was found in 19 patients (31.7%). This clinically occult metastasis was only related to the total number of metastatic LNs in the central compartment. Patient age, gender, tumor size, location, extent of tumor invasion, multiplicity, and presence of thyroiditis were not related to metastasis in the lateral compartment. Detection of lateral neck SLNs upon biopsy with radioisotope was also feasible in level II and contralateral neck.

CONCLUSIONS

Sentinel lymph node biopsy is a useful method for evaluating the occult lateral neck lymph node status in patients with papillary thyroid carcinoma, especially in the cases of central neck node metastasis.

Role of prophylactic ipsilateral central compartment lymph node dissection in papillary thyroid microcarcinoma

Central compartment lymph node (CCLN) management in patients without clinical or radiologic evidence of CCLN metastasis is debatable. The aim of the present study was to evaluate outcomes of surgery for papillary thyroid microcarcinoma (PTMC) with prophylactic ipsilateral CCLN dissection (PI-CCND) in a large cohort of patients treated at one single institution in a 5-year follow-up. Between January 2000 and December 2005, 2192 patients with papillary thyroid carcinoma underwent thyroid surgery. Inclusion criteria were patients with PTMC, absence of clinical or radiologic evidence of CCLN metastasis, and a follow-up for a period ≥60 months. Data from 842 patients were retrieved in the current retrospective cohort study. PI-CCND was routinely performed in addition to thyroid surgery in all cases. Ipsilateral CCLN metastasis was found in 218 patients (25.9%). Postoperative complications included 76 cases of transient hypoparathyroidism (9%), 11 cases of permanent hypoparathyroidism (2.6%), four cases of vocal cord palsy (0.5%), and one case of bleeding (0.1%). Univariate analysis and multivariate logistic regression analysis revealed that CCLN metastasis was statistically significantly correlated with tumor size and extracapsular invasion. Recurrence has been observed to date in 19 patients (2.26%). No CCLN site recurrence occured in patients who underwent PI-CCND. This study demonstrates the technical feasibility and safety of PI- CCND, which is a better way to determine lymph node status for a more accurate staging of disease and risk stratification. PI-CCND should be considered even if clinical or radiological exams are negative for CCLN metastasis.

Patterns of lymph node metastases in papillary thyroid carcinoma: results from consecutive bilateral cervical lymph node dissection

BACKGROUND

In patients with papillary thyroid carcinoma (PTC), the appropriate extent of lymph node dissection has not yet been established due to lack of accurate patterns of lymph node metastases (LNM). The aim of this study was to clarify the LNM pattern in PTC patients based on our institution's experience with a consistent technique of bilateral neck dissection, and to consider the rational extent of lymph node dissection.

METHODS

Between 1990 and 1999, 152 consecutive patients with PTC who underwent curative total thyroidectomy and bilateral neck dissection as initial treatment were analyzed. The patterns of LNM according to clinicopathological classification were analyzed using the lymph node ratio (LNR; number of metastatic lymph nodes/number of dissected nodes) and frequency (FLNM; number of patients with LNM/number of dissected patients) in cervical compartments.

RESULTS

Regardless of clinicopathological classification, LNR in the central compartment was consistently higher than in other compartments, and FLNM in the ipsilateral lateral compartment was consistently higher than in other compartments except for multifocal tumors. The LNR and FLNM in the contralateral lateral compartment were significantly higher in advanced (≥T3) cases than in cases with smaller tumors (T1) and were comparable to those in the ipsilateral lateral compartment in advanced (≥T3) cases.

CONCLUSIONS

The pattern of LNR provided a better reflection of the patterns of LNM. In terms of the LNR, central neck dissection is the basic extent of lymph node dissection for all clinically apparent PTC. In advanced patients, it is also advisable to include bilateral lateral neck dissection.

The role of preoperative neck ultrasounds to assess lymph nodes in patients with suspicious or indeterminate thyroid nodules

BACKGROUND AND OBJECTIVES

Currently there are no recommendations for obtaining a preoperative neck ultrasound for patients with suspicious or indeterminate thyroid nodules. Because a preoperative surgical ultrasound can detect suspicious lymph nodes that could result in ultimately altering surgical management, we chose to study which variables were predictive of this change.

METHODS

Medical records of 173 patients who presented between January 2006 and December 2010 with suspicious or indeterminate thyroid cytology were retrospectively reviewed. Clinicopathological variables were analyzed to determine factors predictive of malignancy and a change in operative approach.

RESULTS

One hundred thirty-four of 173 patients were evaluable. Seventeen of 134 (12.6%) of the preoperative ultrasounds were suspicious. Seven of 134 (5.2%) patients underwent a formal lymph node dissection based on ultrasound findings. Size of tumor, Bethesda FNAB category, and male gender were associated with malignancy while thyroid nodule microcalcifications and category of FNAB were associated with performing lymph node dissections.

CONCLUSION

Thyroid nodule microcalcifications on ultrasound and category of FNAB appear to be the best predictors of metastatic disease. Because the surgical approach was altered in only a few patients, further analysis is needed to delineate whether performing cervical ultrasound for suspicious/indeterminate nodules is cost effective.

Well-differentiated thyroid carcinomas: management of the central lymph node compartment and emerging biochemical markers

Well-differentiated thyroid cancers (WDTCs) are generally indolent cancers that are associated with a low mortality. Although the incidence of these tumors is increasing, there has not been an associated increase in the mortality rates. As we gain a greater understanding and more experience with these good prognosis cancers, the way in which we treat these tumors is evolving. The definition of persistent or recurrent disease has seen a shift from being a clinical and/or radiological diagnosis to now one based on a biochemical blood marker, thyroglobulin. Central lymph node metastases are a very common problem in WDTC, being present in up to 90% of patients. The optimal surgical management of the central lymph node compartment remains a hotly debated topic. This paper identifies these controversies and presents available data surrounding these issues. Biochemical tumor markers are gaining wider use in practice and in time hopefully provide more specific information with which surgical decision-making can be based. A summary of the clinically available markers is presented.

Multi-targeted approach in the treatment of thyroid cancer

While accounting for only 1% of solid organ malignancies (9% in women), thyroid carcinoma is the most common malignancy of the endocrine system. Although most patients have a favorable prognosis, over 1,500 people will die from thyroid carcinoma each year. The spectrum of disease types range from papillary thyroid cancer, which is a well-differentiated indolent tumor, to anaplastic carcinoma, a poorly differentiated fulminant cancer. With advances in diagnostic methods, surgical techniques, and clinical care of patients with thyroid carcinoma, the current management of thyroid cancer demands a multidisciplinary approach. The majority of patients with well-differentiated thyroid carcinoma of follicular cell origin are cured with adequate surgical management; however, some thyroid malignancies such as medullary thyroid carcinoma (MTC) or poorly differentiated thyroid carcinomas frequently metastasize, precluding patients from a curative resection. As such, novel palliative and therapeutic strategies are needed for this patient population. Here, we explore the current management of thyroid carcinoma, including surgical management of the primary tumor, lymph node disease, and locoregional recurrence. Likewise, we explore the application of current molecular techniques, reviewing nearly two decades of data that have begun to elucidate critical genetic pathways and therapeutic drug targets which may be important in specific thyroid tumor types.

Thyroid cancer in older men

This article reviews most common types of thyroid cancer focusing on older males worldwide. Thyroid carcinoma is the most common endocrine malignancy. It includes tumour types that range from localised papillary carcinomas to lethal anaplastic disease. Among elderly population, male gender seems to be highly correlated with the risk and aggressiveness of thyroid cancer. Early diagnosis and urgent aggressive treatment are important for aging patients. This article includes numerous studies which evaluate prevalence, morbidity and mortality of thyroid cancer in older males.

Central lymph node metastasis of unilateral papillary thyroid carcinoma: patterns and factors predictive of nodal metastasis, morbidity, and recurrence

BACKGROUND

Although subclinical cervical lymph node (LN) metastases in papillary thyroid carcinoma (PTC) are common, the efficacy of prophylactic central LN dissection (CLND) is unclear. Few prospective studies have assessed the relationships between complete pathologic information regarding tumors and metastatic nodes in the central compartment. We therefore investigated the pattern and predictive indicators of central LN metastasis, morbidity, and recurrence in patients who underwent total thyroidectomy and prophylactic CLND for unilateral PTC and clinically node-negative neck (cN0) disease.

METHODS

This prospective study involved 184 patients with previously untreated unilateral PTC and cN0 who underwent total thyroidectomy and bilateral CLND. Nodal samples were divided into the prelaryngeal/pretracheal and ipsilateral and contralateral paratracheal regions, with each assessed for clinicopathologic predictors of central metastases. Postoperative morbidity and recurrence were assessed.

RESULTS

Rates of metastasis to ipsilateral and contralateral central compartments were 42.9 and 9.8%, respectively. Multivariate analysis showed that tumor size >1 cm and extrathyroidal extension were independent predictors of ipsilateral metastasis, and ipsilateral metastases independently predicted contralateral metastases (P < 0.05 each). Permanent hypoparathyroidism and incidental recurrent nerve paralysis were found in 1.6 and 0% of patients, respectively. After a mean follow-up of 46 months, none of these patients had recurrence in the central compartment.

CONCLUSIONS

Subclinical metastases are highly prevalent in the ipsilateral central neck of patients with PTC >1 cm. Contralateral central metastases, although uncommon, are associated with ipsilateral central metastases. These findings may guide the necessity and extent of prophylactic bilateral or unilateral CLND.

Preoperative ultrasonographic tumor characteristics as a predictive factor of tumor stage in papillary thyroid carcinoma

BACKGROUND

The purpose of this study was to evaluate the usefulness of tumor characteristics on ultrasonography for predicting the pathologic stage of papillary thyroid carcinoma.

METHODS

We evaluated 354 patients who underwent surgery for papillary thyroid carcinoma (≤2 cm). We analyzed the preoperative ultrasonography findings such as tumor size, shape, margin, echogenicity, calcification, vascularity, and contact with the capsule.

RESULTS

Tumor size, echogenicity, and contact with the capsule were predictive for the presence of extrathyroid extension. Size and echogenicity were significantly associated with central lymph node metastasis in the multivariate analysis. Some ultrasonography characteristics such as round shape, well-defined margin, and isoechoic echogenicity were negative predictive factors for extrathyroid extension and central lymph node metastasis.

CONCLUSION

Preoperative tumor characteristics on ultrasonography correlated with several prognostic factors for papillary thyroid carcinoma and may serve as preoperative supplementary markers for determining the optimal extent of surgery.

Efficacy of preoperative neck ultrasound in the detection of cervical lymph node metastasis from thyroid cancer

OBJECTIVES/HYPOTHESIS

This study was performed to assess the diagnostic accuracy of surgeon-performed preoperative neck ultrasound (US) in the detection of both central and lateral cervical lymph node metastases from thyroid cancer.

STUDY DESIGN

Prospective cohort study.

METHODS

Data for all patients with thyroid cancers and follicular thyroid lesions who were evaluated by means of preoperative neck US were reviewed. The cervical lymph nodes were assessed for suspicion of metastasis based on US characteristics. The diagnostic accuracy of US was determined according to whether histologically confirmed cancer was present in surgical cervical lymph node specimens.

RESULTS

The sensitivity and specificity of US in predicting papillary thyroid carcinoma (PTC) metastasis in the central neck were 30.0% and 86.8%, respectively. The sensitivity and specificity of US in predicting metastasis in the lateral neck were 93.8% and 80.0%, respectively. A subset of patients underwent US followed by revision neck dissection for PTC, and the sensitivity and specificity of US in predicting metastasis in the lateral neck were 100% and 100%, respectively.

CONCLUSIONS

Preoperative neck US is a valuable tool in assessing patients with thyroid cancers. The highly sensitive and specific nature of US in predicting cervical lymph node metastasis in the lateral neck, especially in the setting of recurrent disease, can provide reliable information to assist in surgical management. Although US for central compartment lymphadenopathy in the presence of the thyroid gland is less sensitive and specific than US for the lateral neck, it still provides useful information that can be obtained at the same time the primary thyroid pathology is assessed.

Surgical management of cervical lymph nodes in differentiated thyroid cancer

Well-differentiated thyroid cancer (DTC) carries an excellent prognosis. Although long-term survival rates are high, regional lymph node metastases are common. Surgical management of cervical lymph nodes is integral to the comprehensive treatment of DTC, but data from large randomized trials do not exist to define optimal treatment. Therapy is thus guided by observational data, and founded on an understanding of the behavior of lymphatic metastases in DTC. This article focuses on the significance of lymph node metastases in thyroid cancer, and the strategy for surgical management.

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.

Considerations for personalized surgery in patients with papillary thyroid cancer

BACKGROUND

Personalizing treatment for papillary thyroid cancer (PTC) requires a multidisciplinary approach. The surgical management of PTC has long been based on retrospective studies focusing on endpoints that are of debatable significance. There is considerable debate in the literature regarding the optimal initial treatment for PTC. Many of these issues are discussed in this review. These debates have hindered the development of a tailored treatment strategy.

SUMMARY

The ability to optimally personalize a surgical plan for the treatment of PTC is ultimately dependent on an understanding of the biological behavior of that individual patient's tumor. We are at the genesis of an age where molecular biology advances endeavor to profile a patient's tumor behavior. This review summarizes current strategies for managing PTC, where we are with personalizing surgery for these patients, and where we hope to go. Thyroid surgery is one of the newest fields for the application of minimally invasive techniques and can now be accomplished endoscopically or with robotic assistance in many patients who therefore may benefit from these alternative approaches.

CONCLUSION

When treating a patient with PTC, it seems prudent to weigh the many factors discussed in this review to individualize the most optimal surgical plan.

[Surgery of thyroid carcinoma]

The 5 main types of thyroid cancer (papillary, PTC, follicular, FTC, poorly differentiated, PDTC undifferentiated, UTC, medullary, MTC) not only differ regarding morphology, pathogenesis, genetics,and pathophysiology (iodine metabolism, thyroglobulin and calcitonin production), but also concerning tumor biology, metastatic behavior (lymphogenous, locally invasive and hematogenous routes) and prognosis. Knowledge of these features is the basis of the surgical concept of one or two-stage thyroidectomy, the exceptions and the concept of locoregional lymph node dissection. Lymph node surgery plays an important role in those cancers exhibiting mainly lymph node metastases (PTC, MTC) not only due to frequent recurrences but also due to its potential curative intent. Differentiated carcinomas may have an acceptable prognosis despite local invasion of the cervical aerodigestive system, thus resections are justified when technical prerequisites are given.

Controversies in the surgical management of newly diagnosed and recurrent/residual thyroid cancer

BACKGROUND

Thyroid surgery is the mainstay of treatment for thyroid cancer, but there are options for the surgical approach. There is a general agreement that the goal of thyroid cancer surgery is to remove evident disease, minimize treatment and disease-related morbidity, minimize the risk of recurrence and metastatic spread, and facilitate long-term follow-up. Within these parameters, however, there are a number of controversies regarding the extent of surgery.

SUMMARY

To minimize the risk of recurrence and to optimize the treatment of patients with thyroid cancer, a total thyroidectomy should be performed as the initial operation if the preoperative diagnosis is consistent with thyroid cancer. Macroscopic lymph node involvement does impact recurrence and may influence survival. Therefore, a preoperative ultrasound evaluation of the neck is essential before operative intervention. If pathologic nodes are identified in either the central or lateral neck they should be removed at the initial operation. The role of prophylactic central neck dissection remains controversial, and the risks of this procedure may outweigh the benefits. Therefore, we do not recommend the routine performance of a central neck dissection. Similar to the recent American Thyroid Association guidelines, we agree that their may be a subset of high-risk patients who may benefit from a prophylactic central neck dissection, but that population has yet to be defined. The extent of lateral dissection that is required is also debated as levels 1 and 5 lymph node involvement is uncommon with thyroid cancer. Recurrent disease can be challenging to remove, but several adjuncts are available to maximize the safety and efficacy of reoperation, making it the best option for patients with localized recurrences.

CONCLUSIONS

Total thyroidectomy and neck dissection are very safe procedures when performed by experienced surgeons and can play an essential role in the management of patients with thyroid cancer.

Revised American Thyroid Association management guidelines for patients with thyroid nodules and differentiated thyroid cancer

BACKGROUND

Thyroid nodules are a common clinical problem, and differentiated thyroid cancer is becoming increasingly prevalent. Since the publication of the American Thyroid Association's guidelines for the management of these disorders was published in 2006, a large amount of new information has become available, prompting a revision of the guidelines.

METHODS

Relevant articles through December 2008 were reviewed by the task force and categorized by topic and level of evidence according to a modified schema used by the United States Preventative Services Task Force.

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, and management of benign thyroid nodules. Recommendations regarding the initial management of thyroid cancer include those relating to optimal surgical management, radioiodine remnant ablation, and suppression therapy using levothyroxine. Recommendations related to long-term management of differentiated thyroid cancer include those related to surveillance for recurrent disease using ultrasound and serum thyroglobulin as well as those related to management of recurrent and metastatic disease.

CONCLUSIONS

We created evidence-based recommendations in response to our appointment as an independent task force by the American Thyroid Association to assist in the clinical management of patients with thyroid nodules and differentiated thyroid cancer. They represent, in our opinion, contemporary optimal care for patients with these disorders.

[Risk factors of persistent disease at 5 years from diagnosis in differentiated thyroid cancer: study of 63 patients]

OBJECTIVE

To identify possible risk factors associated with persistent disease 5 years after total or near-total thyroidectomy in patients with differentiated thyroid cancer (DTC).

PATIENTS AND METHOD

Retrospective study evaluating data from 63 patients 5 years after they were first diagnosed of DTC. At this time of the study, 46 subjects were considered disease-free (F group) whereas 17 had evidence of persistent disease or had died from DTC (P group). We compared both groups of patients regarding the following variables: a) variables at diagnosis related to the patient (age, gender) and the tumor (histological type, size, extrathyroidal involvement, vascular invasion, multifocality, lymph node and distant metastases), and b) variables recorded during follow-up: percentage of subjects showing serum stimulated thyroglobulin > or = 10 ng/ml few weeks postoperatively (Tg0) and 6 to 12 months later (Tg1).

RESULTS

Male gender, extrathyroidal involvement and lymph node metastases were more frequent in P group than in F group (41 vs. 11%, 60 vs. 18% and 50 vs. 5.5%; p < 0.05). During the follow-up the percentage of patients showing Tg > or = 10 ng/ml was higher in P group compared to F group, both at a few weeks postoperatively and 6 to 12 months later (Tg0, 75 vs. 13%; Tg1, 69% vs. 0; p < 0,05).

CONCLUSIONS

In our patients, male gender, extrathyroidal involvement, and lymph node metastases at diagnosis were associated with persistent disease 5 years later. Serum stimulated thyroglobulin had a very high predictive value both just after surgery and in the next 6 to 12 months and could help identifying subjects who need a closer follow-up.

Predictive factors for ipsilateral or contralateral central lymph node metastasis in unilateral papillary thyroid carcinoma

OBJECTIVES

To investigate the incidence and the risk factors for occult ipsilateral or contralateral central neck lymph node (LN)metastasis in patients with unilateral papillary thyroid carcinoma (PTC) and a clinically negative neck.

SUMMARY BACKGROUND DATA

Elective central lymph node dissection (CLND) in patients with PTC remains controversial. There have been few prospective studies assessing accurate histopathologic information and predictive factors for the presence of metastasis to the ipsilateral or contralateral central compartment of the neck in patients with PTC and clinically negative neck nodes.

METHODS

We reviewed a prospective protocol of 111 unilateral PTC patients with clinically node-negative necks who have received total thyroidectomy and elective bilateral CLND from 2005 to 2007. The relationships between LN metastasis to the ipsilateral or contralateral central neck compartment and clinico-pathologic factors such as age, sex, size of primary tumor, perithyroidal invasion, lymphovascular invasion, and capsular invasion were analyzed.

RESULTS

Occult central neck LN metastasis was present in 54.1% (60/111). Of these patients, bilateral central LN metastases were present in 50% (30/60), unilateral ipsilateral central LN metastasis in 43.3% (26/60), and unilateral contralateral central LN metastasis in 6.7% (4/60). In the univariate analysis, the rate of ipsilateral central LN metastasis was significantly higher in male patients, high risk MACIS score, carcinoma with a maximal diameter of greater than 1 cm, and carcinoma with lymphovascular invasion (P < 0.05). The rate of contralateral central LN metastasis was significantly higher in cases of carcinoma with a maximal diameter of greater than 1 cm, lymphovascular invasion or histologically proven metastasis to the ipsilateral central LN (P < 0.05). Multivariate analysis showed that the tumor size was an independent risk factor for the presence of ipsilateral central LN metastasis, and the presence of ipsilateral central LN metastasis was the only independent predictor for the presence of contralateral central LN metastasis.

CONCLUSIONS

Unilateral PTC with a maximal diameter of greater than 1 cm is associated with a high rate of ipsilateral central neck LN metastasis. Moreover, ipsilateral central LN metastasis is a potential independent predictor of synchronous contralateral central LN metastasis. These findings suggest that contralateral as well as ipsilateral elective CLND, performed during the initial thyroid operation, may be effective in the management of patients with unilateral PTC having a maximal diameter of greater than 1 cm and ipsilateral central LN metastasis.

Management of regional metastases in well-differentiated thyroid cancer

Thyroid cancer represents the most common endocrine cancer, and rates have been increasing over the last 3 decades. The treatment of cervical metastases in well differentiated thyroid cancer remains in evolution. Many questions require further resolution. Unlike many other malignancies, most large studies have found that overall survival is not significantly affected by regional metastases. On the other hand, several studies have noted that regional disease may decrease survival in selected patient groups. The greatest effect of lymph node metastases seems to be an increase in recurrence rates. Except for the compartment-oriented removal of clinically positive nodes, few strong recommendations may be made.

Impact of 131I SPECT/spiral CT on nodal staging of differentiated thyroid carcinoma at the first radioablation

The purpose of this study was to determine the diagnostic value of 131I SPECT/spiral CT (SPECT/CT) on nodal staging of patients with thyroid carcinoma at the first ablative radioiodine therapy.

METHODS

Fifty-seven patients were studied using SPECT/CT 3-4 d after receiving 3.96+/-0.5 GBq of 131I for radioablation of thyroid remnants after a thyroidectomy for differentiated thyroid carcinoma. In addition to planar whole-body scintigraphy, SPECT/CT of the neck was performed using a hybrid camera combining a double-head SPECT camera with either a 2-slice (n=23) or a 6-slice (n=34) spiral CT scanner. The planar scans and the SPECT/CT images were evaluated for cervical tracer uptake independently of each other and of the clinical findings.

RESULTS

SPECT/CT led to a revision of the original diagnosis in 28 of 143 cervical foci of radioiodine uptake seen on planar imaging. In particular, SPECT/CT reclassified as benign 6 of 11 lesions considered to be lymph node metastases and 11 of 15 lesions considered to be indeterminate. Furthermore, SPECT/CT allowed the identification of 11 lymph node metastases classified as thyroid remnant or as indeterminate on planar imaging. Based on this revision, SPECT/CT yielded a gain in information on nodal stage in 20 of the 57 patients studied (35%, P<0.03). SPECT/CT altered nodal stage from N0 to N1 in 2 of 20 patients and from indeterminate (Nx) to N1 in 6 of 30 patients. The result was a change in risk stratification conforming to the classification proposed by the International Union Against Cancer in 14 patients (25%).

CONCLUSION

SPECT/CT determines lymph node involvement at radioablation performed for thyroid cancer more accurately than does planar imaging. SPECT/CT may alter management in roughly one quarter of patients with thyroid carcinoma by upstaging or downstaging their disease.

Surgical approaches in thyroid cancer and lymph-node metastases

Thyroid cancer collectively encompasses a variety of tumors of disparate morphology and biology. With the exception of radio-iodine therapy for iodine-concentrating well-differentiated thyroid cancers, surgery is the foremost and generally sole effective treatment. Because the growth patterns of these tumors vary tremendously, there is a need to tailor the extent of dissection to the respective tumor entity, especially for less aggressive tumors. No international consensus exists about what precisely constitutes a 'low-risk' or 'high-risk' tumor. Established indications for less-than-total thyroidectomy include small (<or=1 cm), unifocal, and non-metastatic papillary thyroid carcinomas (PTC), and minimally invasive follicular thyroid carcinomas (FTC; invasion of the tumor capsule only). Whether occult multifocal PTC and minimally invasive FTC with histopathological evidence of vascular invasion also fall into the 'low-risk' category remains unclear. For node-positive thyroid cancers, compartment-oriented microdissection is the gold standard of care, whereas the concept of prophylactic lymph-node dissection continues to arouse controversy. Most experts agree that routine lymph-node dissection is unnecessary for low-risk well-differentiated thyroid cancer (DTC). Because occult lymph-node metastases are frequent in high-risk PTC and medullary thyroid carcinoma, compartment-oriented microdissection helps prevent reoperations for 'recurrences' arising from residual nodes, sparing patients the excess morbidity from reoperations in the neck. Because of the looming epidemic of early forms of thyroid cancer, an international consensus is needed regarding (1) the definition of low- versus high-risk tumors; (2) classification of neck nodes; and (3) lymph-node dissection terminology.

Is central neck dissection a safe procedure in the treatment of papillary thyroid cancer? Our experience

BACKGROUND AND AIMS

The role of central neck dissection in the treatment of papillary thyroid carcinoma is debated. This retrospective investigation was undertaken to assess whether it augments total thyroidectomy morbidity.

PATIENTS/METHODS

A total of 305 consecutive patients who had undergone total thyroidectomy for papillary thyroid carcinoma were divided into three groups: group A (n = 64) showed evidence of node metastases and received therapeutic bilateral central node dissection; group B (n = 93) showed negative nodes and received prophylactic ipsilateral central node dissection; group C (n = 148) showed negative nodes and received total thyroidectomy alone. The rates of transient and permanent complications within the three groups were compared.

RESULTS

Histopathological examination detected node metastases in 46 (72%) group A patients and in 20 (21%) group B patients. Parathyroid autotransplantation was carried out in 41 (64%) patients in group A, 55 (59%) in group B, and 43 (29%) in group C (P < 0.001). One or more parathyroid glands were found in 20% of the specimens from group A, 11% of those from group B, and 9% of those from group C. None of the patients in either group A or group B reported permanent laryngeal recurrent nerve paralysis, but two (1.3%) in group C did. Transient laryngeal recurrent nerve paralysis occurred most often in group A patients (7.8% versus 5.4% versus 1.3%, respectively) and was bilateral in two patients (one in group A and one in group B). None of the patients in either group A or group B developed permanent hypoparathyroidism, but four (2.7%) in group C did. Transient hypoparathyroidism was highest in group A patients (31% versus 27% versus 13%, respectively; P = 0.003). Postoperative bleeding requiring reoperation occurred in one group B patient and in two group C patients.

CONCLUSIONS

Central neck dissection did not increase permanent morbidity and revealed a significant rate of nonclinically evident node metastases. In experienced hands, central neck dissection should be routinely combined with total thyroidectomy in the primary treatment of pre- or intraoperatively diagnosed papillary thyroid cancer. When no macroscopic evidence of metastasis is present, ipsilateral central neck dissection is the best treatment strategy in a balanced decision between the need for achieving local radical excision, correct disease staging, and reducing the risk of complications.

Efficacy of nodal dissection for treatment of persistent/recurrent papillary thyroid cancer

CONTEXT

Although commonly performed, data are lacking regarding efficacy and safety of lymph node dissection (LND) for recurrent/persistent papillary thyroid cancer (PTC).

OBJECTIVE

Evaluate the efficacy and morbidity of LND in recurrent/persistent PTC.

DESIGN

Retrospective review of central or lateral LND performed for persistent/recurrent PTC between January 2004 and March 2006.

SETTING

Multidisciplinary thyroid cancer clinic with a single surgeon at an academic medical center.

PARTICIPANTS

Seventy-five patients who underwent 79 LND for persistent/residual PTC. Safety analysis included all 79 resections. Exclusion criteria for the efficacy analysis were factors prohibiting evaluation of thyroglobulin (Tg) response. Forty-one resections were included in the efficacy analysis.

INTERVENTION

Selective LND per standard of care.

MAIN OUTCOME MEASURE

Primary outcome was the Tg response to LND. Secondary outcomes were surgical complications.

RESULTS

Thirty-nine of the 41 evaluable resections also had Tg data allowing classification of Tg response. Of 39 classifiable resections, 16 (41%) resulted in undetectable postoperative stimulated Tg levels. An additional 12 resections resulted in significant (> or =50%) reductions in suppressed or stimulated Tg levels for an overall improvement rate of 72%. Of all 79 resections, 25 (32%) resulted in minor and 7 (9%) resulted in major complications.

CONCLUSIONS

LND for persistent/recurrent PTC is a relatively safe procedure in experienced hands. It can lead to an undetectable Tg in 41% of cases and produce a major Tg reduction in an additional 31%. Its efficacy in short-term follow-up is comparable with that reported for I-131, and it should be considered in the management of persistent/recurrent PTC.

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.

Extent of prophylactic lymph node dissection in the central neck area of the patients with papillary thyroid carcinoma: comparison of limited versus comprehensive lymph node dissection in a 2-year safety study

BACKGROUND

To compare the "comprehensive" (including bilateral paratracheal, pretracheal, prelaryngeal lymph nodes) (CCND) with "limited" (saving contralateral paratracheal lymph nodes) central node dissection (LCND) for postoperative complications and disease recurrence rate in sonographically node-negative papillary thyroid carcinomas.

MATERIALS AND METHODS

From 2003 to 2005, 114 consecutive patients, diagnosed as sonographically node-negative thyroid papillary carcinomas, were included retrospectively. Among them, the LCND was performed in 56 patients and CCND in 58 patients, in combination with total thyroidectomy, based on the operator-dependent decision. We compared the complication rates and the recurrence rates between these two groups with a mean follow-up duration of 2 years.

RESULTS

Transient hypocalcemia was more frequent in the CCND group than in the LCND group (48.3% vs 26.8%, P = .02, odds ratio [OR] = 2.55). However, the other complication rates were similar in the two groups. In addition, the immediate postoperative reduction of parathyroid hormone (PTH) was more evident in the CCND group. The postoperative PTH levels increased up to a similar level (12.4 vs 11.8 pg/mL) over 6 months. The incidence of permanent hypocalcemia did not differ significantly between the two groups. Four (7.1%) and five recurrences (8.6%) were found in two groups, respectively, implying similar oncological safety during the 2-year follow-up.

CONCLUSION

The LCND with total thyroidectomy could be an alternative treatment option for node-negative papillary thyroid carcinomas, because LCND had fewer short-term hypocalcemia and similar oncological outcomes during the 2-year follow-up. Further study enrolling a large number of patients with long-term follow-up is needed.

Papillary thyroid cancer: monitoring and therapy

The last 10 years have seen a major paradigm shift in the management of thyroid cancer, with greater reliance on serum thyroglobulin and neck ultrasonography, and less emphasis on routine diagnostic whole-body radioactive iodine scanning for detection of recurrent disease. As our follow-up tests become more sensitive for detection of recurrent disease, we are finding many asymptomatic patients who have low-level persistent disease many years after initial therapy that may or may not benefit from additional testing and therapy. These difficult issues have been addressed by at least five different sets of guidelines published recently by various thyroid specialty organizations around the world. In this article, the authors compare and contrast the recommendations from the various guidelines in an attempt to define areas of consensus and explore possible reasons for differing recommendations.

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.

Central Lymph Node Dissection in Differentiated Thyroid Cancer

BACKGROUND

There has been renewed interest in extensive lymph node dissection for papillary thyroid cancer (PTC), and a number of reports have been published concerning compartment-oriented dissection of regional lymph nodes in PTC. A comprehensive review of this body of literature using evidence-based methodology is pending.

METHODS

Systematic review of the literature using evidence-based criteria.

RESULTS

Issue 1: Systematic compartment-oriented central lymph node dissection (CLND) may decrease recurrence of PTC (Levels IV and V data, no recommendation) and likely improves disease-specific survival (grade C recommendation). Limited level III data suggest survival benefit with the addition of prophylactic dissection to thyroidectomy (grade C recommendation). The addition of CLND to total thyroidectomy can significantly reduce levels of serum thyroglobulin and increase rates of athyroglobulinemia (level IV data, no recommendation). Issue 2: There may be a higher rate of permanent hypoparathyroidism and unintentional permanent nerve injury when CLND is performed with total thyroidectomy than for total thyroidectomy alone (grade C recommendation). Issue 3: Reoperation in the central neck compartment for recurrent PTC may increase the risk of hypoparathyroidism and unintentional nerve injury when compared with total thyroidectomy with or without CLND (grade C recommendation), supporting a more aggressive initial operation.

CONCLUSION

Evidence-based recommendations support CLND for PTC in patients under the care of experienced endocrine surgeons.

Routine ipsilateral level VI lymphadenectomy reduces postoperative thyroglobulin levels in papillary thyroid cancer

BACKGROUND

Lymphadenectomy in clinically node-negative papillary thyroid cancer (PTC) is controversial. The aim of this study is to determine whether routine ipsilateral level VI lymphadenectomy (LNDVI) has advantages over total thyroidectomy (TT) alone.

METHODS

A retrospective cohort study was performed. Patients undergoing surgery for clinically node-negative PTC >1 cm were included. Group A had TT and LNDVI. Group B had TT alone. The number of radioiodine treatments and postablative stimulated serum thyroglobulin (TG) levels were compared.

RESULTS

From 1995 to 2005, 447 patients with clinically node-negative PTC underwent surgery. Group A (n = 56) had TT and LNDVI. Group B (n = 391) had TT alone. Tumor size was equivalent (group A, 20 mm; group B, 23 mm; P = .14) as were MACIS (metastasis, age, completeness of resection, invasion, and size) scores (group A, 4.70; confidence interval, 4.23-5.17; group B, 4.73; confidence interval, 4.4-5.05). Serum postablative TG levels were lower in group A (0.4 microg/L) compared with group B (9.3 microg/L), P = .02. More patients had undetectable TG levels in group A (72%) than in group B (43%) (P < .001). Long-term complications rates were the same.

CONCLUSIONS

In PTC the addition of routine LNDVI results in lower postablation levels of TG and higher rates of athyroglobulinemia when compared with TT alone.

Cyclic strain-mediated matrix metalloproteinase regulation within the vascular endothelium: a force to be reckoned with

The vascular endothelium is a dynamic cellular interface between the vessel wall and the bloodstream, where it regulates the physiological effects of humoral and biomechanical stimuli on vessel tone and remodeling. With respect to the latter hemodynamic stimulus, the endothelium is chronically exposed to mechanical forces in the form of cyclic circumferential strain, resulting from the pulsatile nature of blood flow, and shear stress. Both forces can profoundly modulate endothelial cell (EC) metabolism and function and, under normal physiological conditions, impart an atheroprotective effect that disfavors pathological remodeling of the vessel wall. Moreover, disruption of normal hemodynamic loading can be either causative of or contributory to vascular diseases such as atherosclerosis. EC-matrix interactions are a critical determinant of how the vascular endothelium responds to these forces and unquestionably utilizes matrix metalloproteinases (MMPs), enzymes capable of degrading basement membrane and interstitial matrix molecules, to facilitate force-mediated changes in vascular cell fate. In view of the growing importance of blood flow patterns and mechanotransduction to vascular health and pathophysiology, and considering the potential value of MMPs as therapeutic targets, a timely review of our collective understanding of MMP mechanoregulation and its impact on the vascular endothelium is warranted. More specifically, this review primarily summarizes our current knowledge of how cyclic strain regulates MMP expression and activation within the vascular endothelium and subsequently endeavors to address the direct and indirect consequences of this on vascular EC fate. Possible relevance of these phenomena to vascular endothelial dysfunction and pathological remodeling are also addressed.

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.