Thyroid carcinoma invading the cervicovisceral axis: routes of invasion and clinical implications

Evaluation and Surgical Management of Multiple Endocrine Neoplasias

Multiple endocrine neoplasia (MEN) syndromes are rare autosomal dominant diseases that are associated with a mixture of both endocrine and non-endocrine tumors. Traditionally, there are 2 types of MEN that have unique clinical associations: MEN 1 (parathyroid hyperplasia, pancreatic neuroendocrine tumors, and pituitary tumors) and MEN 2 (medullary thyroid carcinoma and pheochromocytoma), which is further classified into MEN 2A (adds parathyroid adenomas) and 2B (adds ganglioneuromas and marfanoid habitus). Many of the endocrine tumors are resected surgically, and the pre, intra, and postoperative management strategies used must take into account the high recurrence rates asscioated with MEN tumors.

Preoperative Evaluation of Thyroid Cancer: A Review of Current Best Practices

OBJECTIVE

The incidence of thyroid cancer has significantly increased in recent decades. Although most thyroid cancers are small and carry an excellent prognosis, a subset of patients present with advanced thyroid cancer, which is associated with increased rates of morbidity and mortality. The management of thyroid cancer requires a thoughtful individualized approach to optimize oncologic outcomes and minimize morbidity associated with treatment. Because endocrinologists usually play a key role in the initial diagnosis and evaluation of thyroid cancers, a thorough understanding of the critical components of the preoperative evaluation facilitates the development of a timely and comprehensive management plan. The following review outlines considerations in the preoperative evaluation of patients with thyroid cancer.

METHODS

A clinical review based on current literature was generated by a multidisciplinary author panel.

RESULTS

A review of considerations in the preoperative evaluation of thyroid cancer is provided. The topic areas include initial clinical evaluation, imaging modalities, cytologic evaluation, and the evolving role of mutational testing. Special considerations in the management of advanced thyroid cancer are discussed.

CONCLUSION

Thorough and thoughtful preoperative evaluation is critical for formulating an appropriate treatment strategy in the management of thyroid cancer.

Cervical exenteration and its variants for locally advanced thyroid cancer: when, why, and how?

PURPOSE OF REVIEW

To describe the modern surgical approach for management of advanced thyroid cancers infiltrating the cervicovisceral axis with special attention to well differentiated tumors not amenable to organ-sparing techniques. In particular, cervical exenteration, herein defined as the sum of total thyroidectomy, central compartment and lateral neck dissections, variously associated with total laryngectomy and possible partial or total pharyngoesophagectomy, represents an extreme surgical procedure that, in properly selected cases, allows for reasonable palliation of central compartment life-threatening signs/symptoms if not cure for an advanced oncologic condition.

RECENT FINDINGS

Cervical exenteration is not contraindicated by the presence of limited distant metastases at presentation. Even though it requires that the patient is in general good health as it can be associated with a number of complications and long in-hospital stay, when appropriately planned and performed according to the most recent reconstructive nuances, it allows good oncologic outcomes that are not inferior to those described for similarly advanced primaries of the upper aerodigestive tract. In addition, quality of life and functional results are not significantly different from those described after total laryngectomy for primary laryngeal squamous cell carcinomas.

SUMMARY

Cervical exenteration requires a tertiary, expert, multidisciplinary effort in terms of diagnosis, surgical performance, and postoperative care. A patient-centered decision process is strongly warranted taking into consideration alternative therapeutic and symptom-based palliative strategies.

Surgical strategy of locally advanced differentiated thyroid cancer

Approximately 20% of patients with differentiated thyroid cancer (DTC) have direct tumor extension with invasion of the surrounding tissues such as the larynx, trachea, esophagus, or recurrent laryngeal nerve. Recent progress of molecular-targeted therapy, such as the use of tyrosine kinase inhibitors, improves survival outcome in patients with advanced DTC. However, induction of tyrosine kinase inhibitors for locally-advanced DTC has presented novel fatal adverse events including fistula in patients with infiltration toward to the trachea, pharynx and esophagus, and fatal bleeding in patients with great vessel invasion. Surgery therefore still has an important role in DTC management, particularly in local control. The surgical strategy for laryngeal/tracheal invasion, which commonly occurs by DTC, is decided according to the extension (depths and area) of the tumor. The "shave procedure" is performed when the tumor has superficially invaded the larynx/trachea. However, intra-luminal extension requires resection and reconstruction of the larynx/trachea wall. Large veins, such as the internal jugular vein and the subclavian vein, are also frequently directly invaded by DTC. Three types of jugular vein reconstruction have been advocated to avoid fatal complications according to bilateral jugular vein ligation. The majority of carotid artery invasion by DTC can be managed with tumor resection of the sub-adventitial layer without reconstruction surgery using an artificial vessel. In this review article, we examine surgery for advanced DTC, showing the surgical strategy toward DTC that has invaded the laryngotracheal, recurrent laryngeal nerve, esophagus/hypopharynx, or great vessels.

Analysis of Pattern of Laryngotracheal Invasion by Papillary Thyroid Carcinoma and Their Management: Our Experience

To analyse the pattern of laryngotracheal invasion (LTI) by papillary-thyroid-carcinoma (PTC) and outcomes of their management. We undertook a retrospective chart review to study patterns of LTI by PTC and to evaluate outcomes of surgical modalities used to treat PTC with LTI. Out of 246cases of PTC, 26-cases had LTI (male-12, female-14, mean-age-55.6 years, range 42-73 years). Common clinical presentation were neck swelling, respiratory distress/stridor and vocal cord paralysis in 100%, 8 (30.8%) and 10 (38.5%) cases respectively. PTC was staged according to AJCC-TNM staging system (T4a-24, T4b-02, N1a-12, N1b-14, M0-25, and M1-01). CT-scan showed obvious LTI and tracheal narrowing in 11(42.3%) and 18(69.2%) cases respectively. All cases underwent total thyroidectomy with central-compartment-clearance. Unilateral and bilateral lateral-neck-dissection was performed in 08 and 06cases respectively. Pattern of Intra-operative LTI were as follows: trachea-13cases, trachea and cricoid-05cases, thyroid cartilage-6cases, trachea, cricoid and thyroid cartilage-2 cases and intra-luminal involvement in 4cases. Modified Shin's staging was used to stage LTI. LTI were superficial, deep-extra-luminal and intra-luminal in 13, 09 and 04cases respectively. LTI was managed by shave-excision, window-resection of trachea, sleeve-resection of trachea and anastomosis, partial laryngectomy and total-laryngectomy in 13,02,04,05 and 2 cases respectively. All patients received radio-active-iodine (RAI) and TSH-suppression-therapy post-operatively. Mean follow-up period was two-years (range 18-30 months). One-case had radio-iodine non-avid local recurrence with lung metastases one-year post-operatively. Shave-excision is adequate for tumours not infiltrating into outer perichondrium. Tracheal-resection and total/partial laryngectomy may be required in cases with laryngo-tracheal cartilage or intra-luminal involvement. Adequate surgical excision along with postoperative RAI and TSH-suppression-therapy gives good loco-regional disease control in PTC with LTI.

Medullary Thyroid Cancer: An Experience from a Tertiary Care Hospital of a Developing Country

Background

Medullary thyroid carcinoma (MTC) is a rare type of thyroid cancer that occasionally occurs as part of MEN2A. The universal treatment of MTC is total thyroidectomy with central lymph node dissection. For disease progression, carcinoembryonic antigen (CEA) and calcitonin (CTN) need to be followed. Our aim was to study the presence and patterns of the above-mentioned characteristics of MTC in our population.

Methodology

This retrospective study was conducted in a tertiary care hospital of Pakistan in which data of thirty-two medullary thyroid cancer patients over the past 20 years were reviewed and analysed after fulfilment of inclusion criteria. Their clinical, pathological, biochemical and treatment modalities were recorded through a retrospective review of their medical record files.

Results

The mean age of patients was 42.88 ± 2.67 years in our study, with a male-to-female ratio of 2:1. Patients with sporadic MTC were 68.8%, while 31.2% were familial. The rates of metastasis were highest in bones followed by lungs and liver. Total thyroidectomy was performed in 26 (81.2%) patients and among those chemotherapy and XRT were performed in one and two patients, respectively. Histologically, the mean tumour size was 7.62 ± 3.64 cm. Median pre-surgery calcitonin was 5756 pg/ml that decreased to 29.3 pg/ml post-surgery. Median pre-surgery CEA level was 246.5 ng/ml that decreased to 6.39 ng/ml post-surgery. Two patients were RET positive.

Conclusion

MTC usually presents in the fourth decade of life with male predominance and mostly sporadic occurrence. Total thyroidectomy with subsequent serial calcitonin and CEA levels thereafter are the mainstay of treatment and follow-up.

Medullary Thyroid Carcinoma Presenting as Metastatic Disease to the Breast

Medullary thyroid carcinoma (MTC) is a neuroendocrine tumor that is derived from C cells of the thyroid gland. It is a rare aggressive tumor, known to metastasize to lymph nodes, liver, bones, and lungs. A 41-year-old female, who presented with a breast mass, was initially diagnosed with invasive ductal carcinoma. She was also found to have a thyroid mass which was later diagnosed as MTC. On a rereview of the breast pathology, the morphologic features were strikingly similar to the MTC. Further investigation revealed that this was in fact a very rare case of MTC that had metastasized to the breast. We have identified 20 cases of MTC metastasizing to the breast in the literature that supports its occurrence as a real possibility. Albeit rare, medullary thyroid carcinoma should be considered in the differential diagnosis of a breast mass.

The role of laryngectomy in locally advanced thyroid carcinoma. Review of 16 cases

SUMMARY

Locally advanced disease with larynx invasion is a challenge to the surgeon, but laryngectomy is almost never necessary in thyroid carcinoma. The aim of this study was to review the clinical outcomes of patients with locally advanced thyroid carcinoma invading the larynx who underwent laryngectomy. A case series of patients treated in a tertiary care hospital was reviewed. Data about the type of operation, method of reconstruction, complications and overall survival of 16 patients operated on between 2002 and 2015 with larynx invasion is presented. There were 10 females. The mean age was 63 ± 8.8 years. Besides total thyroidectomy and neck dissection, four patients underwent total pharyngolaryngectomy, 11 total laryngectomy and one hemi-laryngectomy. Reconstruction was made with regional flaps in 10 patients (7 pectoral/Bakamjian flaps and 3 gastric pull-through procedures) and a jejunum free flap in one patient. Two patients needed carotid artery reconstruction. Five tumours were classic (conventional) papillary carcinoma variants, while the others were aggressive histological varieties (insular, tall cell, sclerosing). The mean tumour size was 4.3 ± 1.6 cm. All tumours had lymphovascular invasion and 12 had positive lymph nodes. Concomitantly, oesophageal/hypopharyngeal invasion was present in 7 cases and invasion of carotid vessels in 2 cases. There were two postoperative deaths and two anastomotic leaks that were treated conservatively. The mean overall survival was 31 ± 33 months (median 27.6 months, range 0-120). Laryngectomy is an alternative surgical procedure to control selected cases of advanced thyroid carcinoma that offers good local control and long term survival.

International neuromonitoring study group guidelines 2018: Part II: Optimal recurrent laryngeal nerve management for invasive thyroid cancer-incorporation of surgical, laryngeal, and neural electrophysiologic data

The purpose of this publication was to inform surgeons as to the modern state-of-the-art evidence-based guidelines for management of the recurrent laryngeal nerve invaded by malignancy through blending the domains of 1) surgical intraoperative information, 2) preoperative glottic function, and 3) intraoperative real-time electrophysiologic information. These guidelines generated by the International Neural Monitoring Study Group (INMSG) are envisioned to assist the clinical decision-making process involved in recurrent laryngeal nerve management during thyroid surgery by incorporating the important information domains of not only gross surgical findings but also intraoperative recurrent laryngeal nerve functional status and preoperative laryngoscopy findings. These guidelines are presented mainly through algorithmic workflow diagrams for convenience and the ease of application. These guidelines are published in conjunction with the INMSG Guidelines Part I: Staging Bilateral Thyroid Surgery With Monitoring Loss of Signal. Level of Evidence: 5 Laryngoscope, 128:S18-S27, 2018.

Thyroid cancer with tracheal invasion: a pathological estimation

We review the clinical and pathologic features of seven cases of papillary carcinoma of the thyroid that invaded the trachea and were treated by thyroidectomy, airway resection with reconstructive surgery over an interval of 15 years. We depicted the peculiarity of invasion of well differentiated papillary thyroid carcinoma (PTC) cells is perpendicularly oriented to the tracheal lumen, in between cartilaginous rings, along blood vessels and collagen fibers. Tracheal rings appear non-infiltrated in all histological sections of well differentiated PTC infiltrating the trachea. Similar description of inter-cartilage PTC infiltration into the trachea was first provided by Shin et al. in 1993. Interestingly, our pathological revision support the estimation by Shin et al., though that cartilage rings infiltration did occur in poorly differentiated thyroid cancers with exiguous prognosis.

Management of Invasive Differentiated Thyroid Cancer

BACKGROUND

Invasive disease is a poor prognostic factor for patients with differentiated thyroid cancer (DTC). Uncontrolled central neck disease is a common cause of distressing death for patients presenting in this manner. Advances in assessment and management of such cases have led to significant improvements in outcome for this patient group. This article reviews the patterns of invasion and a contemporary approach to investigation and treatment of patients with invasive DTC.

SUMMARY

Aerodigestive tract invasion is reported in around 10% of case series of DTC. Assessment should include not only clinical history and physical examination with endoscopy as indicated, but ultrasound and contrast-enhanced cross-sectional imaging. Further studies including positron emission tomography should be considered, particularly in recurrent cases that are radioactive iodine (RAI) resistant. Both the patient and the extent of disease should be carefully assessed prior to embarking on surgery. The aim of surgery is to resect all gross disease. When minimal visceral invasion is encountered early, "shave" procedures are recommended. In the setting of transmural invasion of the airway or esophagus, however, full thickness excision is required. For intermediate cases in which invasion of the viscera has penetrated the superficial layers but is not evident in the submucosa, opinion is divided. Early reports recommended an aggressive approach. More recently authors have tended to recommend less aggressive resections with postoperative adjuvant therapies. The role of external beam radiotherapy continues to evolve in DTC with support for its use in patients considered to have RAI-resistant tumors.

CONCLUSIONS

Patients with invasive DTC require a multidisciplinary approach to investigation and treatment. With detailed assessment, appropriate surgery, and adjuvant therapy when indicated, this patient group can expect durable control of central neck disease, despite the aggressive nature of their primary tumors.

Operative management of locally advanced, differentiated thyroid cancer

BACKGROUND

The majority of differentiated thyroid cancer tends to present with limited locoregional disease, leading to excellent long-term survival after operative treatment. Even patients with advanced local disease may survive for long periods with appropriate treatment. The aim of this study is to present our institutional experience of the management of locally advanced differentiated thyroid cancer and to analyze factors predictive of outcome.

METHODS

We reviewed our institutional database of 3,664 previously untreated patients with differentiated thyroid cancer operated between 1986 and 2010. A total of 153 patients had tumor extension beyond the thyroid capsule that invaded the subcutaneous soft tissues, recurrent laryngeal nerve, larynx, trachea, or esophagus. Details on extent of operation and adjuvant therapy were recorded. Disease-specific survival and locoregional recurrence-free probability were determined by the Kaplan-Meier method. Factors predictive of outcome were determined by multivariate analysis.

RESULTS

The median age of the 153 patients with tumor extension beyond the thyroid capsule was 55 years (range 11-91 years). Eighty-nine patients (58.2%) were female. Twenty-three patients (15.0%) were staged as M1 at presentation, and 122 (79.7%) had pathologically involved lymph nodes. The most common site of extrathyroidal extension was the recurrent laryngeal nerve (51.0%) followed by the trachea (46.4%) and esophagus (39.2%). Sixty-three patients (41%) required resection of the recurrent laryngeal nerve due to tumor involvement. After surgery, 20 patients (13.0%) had gross residual disease (R2), 63 (41.2%) had a positive margin of resection (R1), and 70 (45.8%) had complete resection with negative margins (R0). With a median follow-up of 63.9 months, 5-year, disease-specific survival, when stratified by R0/R1/R2 resection, was 94.4%, 87.6%, and 67.9%, respectively (P = .030). The data do not demonstrate a statistical difference in survival between R0 versus R1 (P = .222). The 5-year distant recurrence-free probability for M0 patients was 90.8%, 90.3%, and 70.7% (P = .410). The locoregional recurrence-free probability was 85.8% for R0 patients and 85.5% for R1 patients (P = .593).

CONCLUSION

With an appropriate operative strategy, patients with locally advanced thyroid cancer with an R0 or R1 resection have excellent survival outcome.

The Clinical Significance of the Right Para-Oesophageal Lymph Nodes in Papillary Thyroid Cancer

PURPOSE

Although guidelines indicate that routine dissection of the central lymph nodes in patients with thyroid carcinoma should include the right para-oesophageal lymph nodes (RPELNs), located between the right recurrent laryngeal nerve and the cervical oesophagus and posterior to the former, RPELN dissection is often omitted due to high risk of injuries to the recurrent laryngeal nerve and the right inferior parathyroid gland.

MATERIALS AND METHODS

We retrospectively identified all patients diagnosed with papillary thyroid carcinoma who underwent total thyroidectomy with central lymph node dissection, including the RPELNs, between January 1, 2009 and December 31, 2013 at the Thyroid Cancer Center of Yonsei University College of Medicine, Seoul, Korea.

RESULTS

Of 5556 patients, 148 were positive for RPELN metastasis; of the latter, 91 had primary tumours greater than 1 cm (p<0.001). Extrathyroidal extension by the primary tumour (81.8%; p<0.001), bilaterality, and multifocality were more common in patients with than without RPELN metastasis; however, there were no significant differences in age and sex between groups. A total of 95.9% of patients with RPELN metastasis had central node (except right para-oesophageal lymph node) metastasis, and the incidence of lateral neck node metastasis was significantly higher in patients with than without RPELN metastasis (63.5% vs. 14.3%, p<0.001). Forty-one patients underwent mediastinal dissection, with 11 patients confirmed as having mediastinal lymph node metastasis with RPELN metastasis on pathological examination.

CONCLUSION

RPELN metastasis is significantly associated with lateral neck and mediastinal lymph node metastasis.

Impact of lymph node metastases with recurrent laryngeal nerve invasion on patients with papillary thyroid carcinoma

BACKGROUND

Although rare, invasion by papillary thyroid carcinoma (PTC) of the upper aerodigestive tract significantly affects patients' prognosis and quality of life. Within the central compartment, the recurrent laryngeal nerve (RLN) is most frequently invaded by lymph node metastases (LNM). However, such an invasion has not been described in the literature, although reports on RLN invasion by primary tumors have been published. The present study aimed to characterize LNM with RLN invasion in patients with PTC.

METHODS

The participants of this retrospective investigation were selected from 629 PTC patients who received initial surgical treatment at our institution between January 1981 and December 2012. They included 38 (6%) patients with 40 cases of RLN invasion by LNM (LNM invasion group) and 112 (17.8%) patients with 117 cases of RLN invasion by the primary tumor (primary invasion group).

RESULTS

In the LNM invasion group, 70% of the RLN invasion cases occurred on the right side, whereas those in the primary invasion group were almost equally distributed. RLN invasion caused vocal cord paralysis, affecting 13 nerves (32.5%) in the LNM invasion group and 68 nerves (58%) in the primary invasion group. Significant differences in laterality and preoperative vocal cord paralysis were observed between the two groups. In the LNM invasion group, the longest diameter of metastatic lymph nodes (mean±standard deviation) of patients with RLN paralysis was 21±8 mm, whereas it was significantly different at 14±7 mm in those without RLN paralysis.

CONCLUSIONS

Our results indicate that most patients with RLN invasion by LNM did not experience preoperative vocal cord paralysis. LNM invasion of the RLN (70%) more often occurred on the right side as expected given the complexity and three-dimensional anatomy of the RLN in the right paratracheal region compared to the left. RLN invasion by LNM should be considered if preoperative paratracheal nodal disease, especially when bulky, is noted in the right paratracheal region.

Surgical Treatment of Medullary Thyroid Cancer

Medullary thyroid cancer (MTC) can vary in tumor biology and progression. The most important indicator of distant metastases, determining clinical outcome, is lymph node metastasis to the neck and mediastinum. Surgical cure is within reach in node-negative tumors or node-positive tumors with fewer than 10 lymph node metastases. From a surgical point of view, compartment-oriented lymph node dissection, clearing gross, and occult metastases are important for locoregional tumor control. The discovery of missense germline mutations in the RET proto-oncogene and the close genotype-phenotype correlation in hereditary MTC promoted the worldwide breakthrough of prophylactic thyroidectomy. The best approach to hereditary MTC affords the DNA-based/biochemical concept, which is geared at limiting prophylactic surgery to total thyroidectomy at minimal surgical morbidity before the tumor can spread beyond the thyroid capsule. To improve outcome, routine calcitonin screening in nodular thyroid disease and DNA-based screening of the offspring in RET families are effective interventions.

Management of invasive well-differentiated thyroid cancer: an American Head and Neck Society consensus statement. AHNS consensus statement

BACKGROUND

Invasive differentiated thyroid cancer (DTC) is relatively frequent, yet there is a paucity of specific guidelines devoted to its management. The Endocrine Committee of the American Head and Neck Society (AHNS) convened a panel to provide clinical consensus statements based on review of the literature, synthesized with the expert opinion of the group.

METHODS

An expert panel, selected from membership of the AHNS, constructed the manuscript and recommendations for management of DTC with invasion of recurrent laryngeal nerve, trachea, esophagus, larynx, and major vessels based on current best evidence. A Modified Delphi survey was then constructed by another expert panelist utilizing 9 anchor points, 1 = strongly disagree to 9 = strongly agree. Results of the survey were utilized to determine which statements achieved consensus, near-consensus, or non-consensus.

RESULTS

After endorsement by the AHNS Endocrine Committee and Quality of Care Committee, it received final approval from the AHNS Council.

The feasibility and efficacy of secondary neck dissections in thyroid cancer metastases

The purpose of the study was to assess the feasibility of secondary neck dissections (ND) in different types of thyroid cancer (TC), to evaluate the influence of ND extent on morbidity and to describe biochemical and clinical outcomes. 51 patients previously operated for TC (33-well differentiated TC-WDTC, 15 medullary TC-MTC, 3 poorly differentiated TC-PDTC) presenting detectable nodal disease. Reoperations covered I–VII neck levels. Radical neck dissection was performed in 22 patients, selective neck dissection in 29 patients. 14 central compartment (CC), 10 mediastinal and 41 level IV excisions were performed. Postoperative complications occurred in 13 patients: 4 chyle leaks, 3 massive bleedings, 8 permanent vocal cord pareses, hypoparathyroidism in 22 patients (43.1 %), 2 patients expired in perioperative period. In WDTC: in seven patients thyroglobulin level normalized directly after ND, in ten patients in the follow-up; six patients developed distant metastases. None of the patients with MTC achieved calcitonin level <10 pg/ml; nine patients developed distant metastases. None of the patients with PDTC achieved Tg <2 mg/ml; two patients died, the third developed distant metastases. Secondary ND in TC present a challenge by means of surgical approach and possibility of complications. In MTC and PDTC the long-term results were unsatisfactory. In WDTC, the secondary ND should be performed due to strong indications. Metastases localization in levels IV, VI, VII were connected with high complication rate, but these surgeries were crucial for satisfactory oncological outcomes.

Recombinant human thyrotropin-aided radioiodine therapy in tracheal obstruction by an invading well-differentiated thyroid carcinoma

Papillary thyroid carcinomas (PTCs) usually extend to lymph nodes in the neck and mediastinum. Rarely, they invade the neighboring upper airway anatomical structures. We report a 56-year-old woman who presented with symptoms of upper airway obstruction. Imaging studies revealed a lesion derived from the thyroid which invaded and obstructed the trachea, which appeared to be a highly differentiated PTC. Total thyroidectomy was performed, with removal of the endotracheal part of the mass along with the corresponding anterior tracheal rings. Two months later, a whole body I(131) scan after recombinant human thyroid-stimulating hormone (rh-TSH) administration was performed and revealed a residual mass in upper left thyroid lobe. Subsequently, 150 mCi I(131) were given following rh-TSH administration. Nine months later, there was no sign of residual tumor. This case is the first one reported in the literature regarding rh-TSH administration prior to RAI ablation in a PTC obstructing the trachea.

Clinical predictors of right upper paraesophageal lymph node metastasis from papillary thyroid carcinoma

Background

Central and lateral lymph node metastases are quite common in patients with papillary thyroid carcinoma, and the predictors for those metastases have been well studied. Right upper paraesophageal lymph node metastasis has rarely been studied. The aim of this study was to identify the clinicopathological characteristics that may be risk factors for right upper paraesophageal lymph node metastasis in patients with papillary thyroid carcinoma.

Methods

This was a prospective observational study of 243 patients with papillary thyroid carcinoma (PTC) who underwent total thyroidectomy and comprehensive central lymph node dissection with or without lateral lymph node dissection between April 2008 and January 2010. The clinicopathologic findings from these patients were investigated and the patterns of lymph node metastasis were analyzed in the patients who had right upper paraesophageal lymph node disease.

Results

Of the 243 patients undergoing lymph node dissection, 14 had right upper paraesophageal lymph node metastases. Two of these patients had right upper paraesophageal lymph node metastasis only, without central compartment metastasis. Univariate analysis of clinicopathologic findings showed that right upper paraesophageal lymph node metastasis had significant association with larger primary tumors, multifocal tumors, extrathyroid extension, and lymphatic invasion (p <0.05 for each factor).

Conclusions

Although there were no independent predictors of right upper paraesophageal lymph node metastasis, it can be the only site of metastasis without other compartmental metastasis. Therefore, during surgery for patients with central or lateral lymph node metastases from PTC, it may be helpful to examine the right upper paraesophageal lymph nodes.

Pattern of initial metastasis in the cervical lymph node from papillary thyroid carcinoma

PURPOSES

This study attempted to reveal the pattern of initial lymphatic spread in order to investigate the clinical significances of lymph node metastasis in papillary thyroid carcinoma (PTC) since such information has yet to be elucidated in previous studies.

METHODS

This study reviewed 501 consecutive patients with PTC who had been surgically treated, accompanied by routine node dissection of the central, and lateral compartments. Thirty-eight cases were found to have only one metastatic node, and 62 cases were found to have 2 or 3 metastatic nodes. The locations of these metastatic nodes were mapped, and evaluated.

RESULTS

The initial lymph node metastasis occurred equally in the lateral and central compartments (19 vs. 19 nodes). Metastatic nodes were more frequently found in the central compartment (60 and 65 %) in cases with 2- and 3-node involvements. Twenty-two (60 %) and 33 (65 %) cases had at least one instance of lateral node involvement in those cases, respectively.

CONCLUSIONS

The current results demonstrated the pattern of initial lymphatic spread in PTC cases, and indicated the importance of evaluating the lateral nodes of at least compartments III and IV for accurate pathological staging, as well as for investigating the nature of the disease.

[Extrathyroidal thyroid cancer : results of tracheal shaving and tracheal resection]

Extrathyroidal thyroid cancer invading the laryngotracheal system (UICC stage pT4a) represents a progressive process of infiltration of the tracheal wall layers from the outer to the inner parts of the trachea. These tumors usually present with high proliferation activity correlating with a reduced long-term prognosis. In contrast to intraluminal manifestation requiring complete wall resection, in cases of non-transmural invasion, complete tumor removal can be sometimes achieved by extraluminal tangential resection (shaving). Tangential resections, however, are associated with a higher frequency of microscopically invaded resection margins (R1 resection rate >40%). The available comparative studies (all retrospective, maximum EBM level 3) analyzing oncological outcome show inconsistent results. In more recently published studies, however, complete wall resection in well-differentiated thyroid cancer with tracheal invasion only was found to be associated with longer recurrence-free and tumor-specific survival when compared to shaving. Deep larynx invasion is associated with reduced long-term prognosis when compared to invasion of the trachea. Salvage resections should therefore be performed in selected cases only.

The thyroid and the gut

Thyroid disease is common, and its effects on the gastrointestinal system are protean, affecting most hollow organs. Hashimoto disease, the most common cause of hypothyroidism, may be associated with an esophageal motility disorder presenting as dysphagia or heartburn. Dyspepsia, nausea, or vomiting may be due to delayed gastric emptying. Abdominal discomfort, flatulence, and bloating occur in those with bacterial overgrowth and improve with antibiotics. Reduced acid production may be due to autoimmune gastritis or low gastrin levels. Constipation may result from diminished motility, leading to an ileus, megacolon, or rarely pseudoobstruction. Ascites in myxedema is characterized by a high protein concentration. Graves' disease accounts for 60% to 80% of thyrotoxicosis. Hyperthyroidism is accompanied by normal gastric emptying with low acid production, partly due to an autoimmune gastritis with hypergastrinemia. Transit time from mouth to cecum is accelerated, resulting in diarrhea. Steatorrhea is due to hyperphagia and stimulation of the adrenergic system. Diarrhea in medullary carcinoma of the thyroid (MCT) may be due to elevated calcitonin, prostaglandins, or 5-hydroxyindoleacetic acid. Ileal or colonic function may be abnormal. The esophagus may be compressed by benign processes, but more often by malignancies. MRI and CT scans are the best diagnostic modalities. The gastrointestinal manifestations of thyroid disease are generally due to reduced motility in hypothyroidism, increased motility in hyperthyroidism, autoimmune gastritis, or esophageal compression by a thyroid process. Symptoms usually resolve with treatment of the thyroid disease.

Biomarker-based risk stratification for previously untreated medullary thyroid cancer

CONTEXT

Preoperative neck ultrasonography may yield false-negative findings in more than one-third of medullary thyroid cancer (MTC) patients. If not cleared promptly, cervical lymph node metastases may emerge subsequently. Reoperations entail an excess risk of surgical morbidity and may be avoidable.

OBJECTIVE

This comprehensive investigation aimed to evaluate in a head-to-head comparison the clinical utility of pretherapeutic biomarker serum levels (basal calcitonin; stimulated calcitonin; carcinoembryonic antigen) for indicating extent of disease and providing biochemical stratification of pretherapeutic MTC risk.

DESIGN

This was a retrospective analysis.

SETTING

The setting was a tertiary referral center.

PATIENTS

Included were 300 consecutive patients with previously untreated MTC.

INTERVENTIONS

The intervention was compartment-oriented surgery.

MAIN OUTCOME MEASURE

Stratified biomarker levels were correlated with histopathologic extent of disease.

RESULTS

Higher biomarker levels reflected larger primary tumors and more lymph node metastases. Stratified basal calcitonin serum levels correlated better (r = 0.59) with the number of lymph node metastases than carcinoembryonic antigen (r = 0.47) or pentagastrin-stimulated calcitonin (r = 0.40) levels. Lymph node metastases were present in the ipsilateral central and lateral neck, contralateral central neck, contralateral lateral neck, and upper mediastinum, respectively, beyond basal calcitonin thresholds of 20, 50, 200, and 500 pg/ml. Bilateral compartment-oriented neck surgery achieved biochemical cure in at least half the patients with pretherapeutic basal calcitonin levels of 1,000 pg/ml or less but not in patients with levels greater than 10,000 pg/ml.

CONCLUSIONS

Most newly diagnosed MTC patients, i.e. those with pretherapeutic basal calcitonin levels greater than 200 pg/ml, may need bilateral compartment-oriented neck surgery to reduce the number of reoperations.

[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.

Metastases of well-differentiated thyroid cancer to the gastrointestinal system

BACKGROUND

The incidence of distant metastases at the time of initial presentation of well-differentiated thyroid cancer is approximately 4%. During the course of treatment and follow-up, the prevalence of distant metastases ranges from 2% in low-risk patients up to 33% in high-risk patients. When present, distant metastases occur primarily in the lungs and, to a lesser extent, in bones. Of all sites for distant metastasis, gastrointestinal metastases of thyroid cancer are very uncommon and account for 0.5-1% of all distant metastases.

SUMMARY

Indications of metastases to the gastrointestinal system can be overlooked with traditional total body radioisotope scans that image the abdomen, including both diagnostic and posttherapy scans, because of the confounding presence of physiologic enteric radioactivity. When suspected in high-risk patients, other imaging procedures such as computed tomography, magnetic resonance imaging, and PET-computed tomography should be considered. This communication will review thyroid cancer metastases to the gastrointestinal system in regard to occurrence rate, diagnosis, and treatment.

CONCLUSIONS

Because of the extreme rarity of patients with metastases of thyroid cancer to the gastrointestinal tract, long-term follow-up data as well as information on prognosis are very limited. Aggressive management may provide symptomatic relief or palliation, but cure is unlikely once widespread metastases supervene. Attempts at complete or near-complete surgical resection of the metastases invading the digestive tract, followed by 131-I treatment, offer the best opportunity for improvement but will only rarely result in cure in selected patients.

[Cervicovisceral resection in invasive thyroid tumors]

About 6% of patients with thyroid cancer present with life-threatening tumor invasion of the trachea and/or esophagus. The extent of resection depends on tumor diagnosis and stage (indication only in differentiated and perhaps medullary thyroid cancer without extrapulmonary metastases), extent of aerodigestive invasion, and general health state of the patient. After complete tumor resection, 5-year and 10-year survival rates of 40-75% can be achieved. Incomplete tumor resection however has a negative effect on prognosis. Tangential tumor resection (shaving) is indicated if no transmural invasion of trachea/esophagus has occurred. Tracheal resection can be subdivided into six standard procedures--types 1 and 2: laryngotracheal or tracheal window resection; types 3 and 4: circular resection with primary reconstruction infraglottic or tracheal; and types 5 and 6: laryngectomy and cervical evisceration.

Constitutive RET tyrosine kinase activation in hereditary medullary thyroid cancer: clinical opportunities

The ground-breaking discovery of genotype-phenotype relationships in hereditary medullary thyroid cancer has greatly facilitated early prophylactic thyroidectomy. Its timing depends not solely on a positive gene test but, more importantly, on the type of the REarranged during Transfection (RET) mutation and its underlying mode of RET receptor tyrosine kinase activation. In the past decade, the therapeutic corridor opened by molecular information has been defined down to a remarkable level of detail. Based on mutational risk profiles, preemptive thyroidectomy is recommended at 6 months of age for carriers of highest-risk mutations, before the age of 5 years for carriers of high-risk mutations, and before the age of 5 or 10 years for carriers of least-high-risk mutations. Additional lymph node dissection may not be needed in the absence of increased preoperative basal calcitonin levels. Better comprehension of RET function should enable the design of targeted therapies for RET carriers beyond surgical cure in whom the DNA-based 'window of opportunity' has been missed.

Invasive thyroid cancer: management of the trachea and esophagus

Well-differentiated thyroid cancer most commonly presents as an intrathyroidal tumor; however, extrathyroidal extension occurs in approximately 6% to 13% of patients and carries a significant negative impact on survival. Extrathyroidal disease may involve critical structures in the central neck, including the recurrent laryngeal nerves, trachea, esophagus, and larynx, requiring surgery extending significantly beyond the thyroid gland. Appropriate surgical management is of great importance and can normalize survival curves, whereas gross residual disease postoperatively may lead to recurrence and decreased survival. Adjuvant postoperative therapies for thyroid cancers with extrathyroidal extension include thyroid hormone suppression, radioactive iodine therapy, and external beam radiotherapy. This summary reviews approaches to the management of invasive thyroid cancers involving the aerodigestive tract.

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.

Lymph node dissection in the lateral neck for completion in central node-positive papillary thyroid cancer

BACKGROUND

In papillary thyroid cancer, quantitative relationships may exist between central and lateral neck lymph node metastases, which may be of clinical usefulness.

METHODS

This comparative analysis of central and lateral neck lymph node metastases was undertaken in 88 patients with untreated papillary thyroid cancer who underwent compartment-oriented lymph node dissection in the central and ipsilateral lateral neck. In 32 of these patients, the contralateral lateral neck was dissected in addition.

RESULTS

Central lymph node metastases were categorized in increments of 0 (22 patients), 1-5 (29 patients), 6-10 (12 patients), and more than 10 positive nodes (25 patients). With more than 5 positive nodes, the rates and numbers of lateral lymph node metastases increased from between 45% and 69% to 100% and from a mean of between 2 and 3 to between 6 and 8 lymph node metastases (all P < .001) in the ipsilateral neck; and from between 0% and 33% to between 60% and 71% (P = .009) and from a mean of between 0 and 1 to between 3 and 7 lymph node metastases (P = .003) in the contralateral neck. Lateral lymph node metastases in the contralateral neck always coexisted with metastases in both the central and the opposite lateral neck. When only patients with positive lateral nodes were considered, the successive increase in the number of lateral lymph node metastases was still present. Altogether, the ipsilateral neck harbored more often lateral lymph node metastasis with more positive lateral nodes than the contralateral neck.

CONCLUSION

These histopathologic associations may provide a foundation for more evidence-based decisions regarding lymph node dissection of the lateral neck compartments in patients with node-positive papillary thyroid cancer.

Prediction of mediastinal lymph node metastasis in papillary thyroid cancer

Because of the rarity of mediastinal lymph node metastasis, no evidence exists regarding risk factors indicating its presence. This study aimed to identify risk factors representing potential triggers of imaging for mediastinal lymph node metastasis. Carried out was an analysis of 392 consecutive patients with node-positive papillary thyroid cancer referred to a tertiary surgical center. Significant univariate associations (P </= 0.001) existed, after correction for multiple testing, between mediastinal lymph node metastasis and poor tumor differentiation (24% versus 2%), number of positive lymph nodes (mean 14.4 versus 7.3 nodes), and distant metastasis (43% versus 11%). Only nominally significant were age at first tumor diagnosis (47.7 versus 39.1 years; P = 0.042), extrathyroidal tumor extension (76% versus 53%; P = 0.044), and bilateral lymph node metastasis (81% versus 49%; P = 0.006). In the initial and optimized multivariate logistic regression models, which included all significant variables from the above analysis, only poor tumor differentiation (odds ratio 11.6-14.6) and distant metastasis (odds ratio 5.4-6.1) represented significant (P </= 0.005) predictors of mediastinal lymph node metastasis. These two variables featured excellent negative predictive values of 96%. Regarding prediction of mediastinal lymph node metastasis, poor tumor differentiation was more discriminatory than distant metastasis, as reflected in a better accuracy (94% versus 86%) and positive predictive value (42% versus 18%). We conclude that, subject to validation in independent series, patients with poorly differentiated papillary thyroid cancers, which are rare, should be ideal candidates for mediastinal imaging because 5 of 12 patients (42%) having this condition in the present investigation harbored mediastinal lymph node metastasis.

18F-dihydroxyphenylalanine PET in patients with biochemical evidence of medullary thyroid cancer: relation to tumor differentiation

Curative treatment for recurrent medullary thyroid cancer (MTC), diagnosed by rising serum calcitonin, is surgery, but tumor localization is difficult. Therefore, the value of 18F-dihydroxyphenylalanine PET (18F-DOPA PET), 18F-FDG PET, (99m)Tc-V-di-mercaptosulfuricacid (DMSA-V) scintigraphy, and MRI or CT was studied.

METHODS

Twenty-one patients with biochemical recurrent or residual MTC underwent 18F-DOPA PET, 18F-FDG PET, DMSA-V scintigraphy, and MRI or CT. Patient- and lesion-based sensitivities were calculated using a composite reference consisting of all imaging modalities.

RESULTS

In 76% of all patients with MTC, one or more imaging modalities was positive for MTC lesions. In 6 of 8 patients with a calcitonin level of <500 ng/L, imaging results were negative. In 15 patients with positive imaging results, 18F-DOPA PET detected 13 (sensitivity, 62%; with 4.6 lesions per patient [lpp]). Morphologic imaging (n = 19) was positive in 7 (sensitivity, 37%; 4.7 lpp), DMSA-V (n = 18) in 5 (sensitivity, 28%; 1.1 lpp), and 18F-FDG PET (n = 17) in 4 (sensitivity, 24%; 1.6 lpp). In a lesion-based analysis, 18F-DOPA PET detected 95 of 134 lesions (sensitivity, 71%), morphologic imaging detected 80 of 126 (sensitivity, 64%), DMSA-V detected 20 of 108 (sensitivity, 19%), and 18F-FDG PET detected 48 of 102 (sensitivity, 30%). In 2 of 3 patients with a calcitonin/carcinoembryonic antigen (CEA) doubling time of < or =12 mo, 18F-FDG PET performed better than 18FDOPA PET; in the third patient, 18F-FDG PET was not performed.

CONCLUSION

MTC lesions are best detectable when serum calcitonin was >500 ng/L. 18F-DOPA PET is superior to 18F-FDG PET, DMSA-V, and morphologic imaging. With short calcitonin doubling times (< or =12 mo), 18F-FDG PET may be superior.

Updated definition of level VI lymph node classification in the neck

CONCLUSION

This update will enable us to precisely address the involvement pattern of level VI and to standardize treatment procedures in order to refine their indications and eventually improve their results and avoid treatment morbidity.

BACKGROUND

The neck level classification is being used worldwide to describe the lymph nodes status of the neck. It provides standardized data to properly evaluate and then improve our protocols for the management of neck metastasis in an evidence-based medical manner. Although level VI treatment is challenging in cancer of the larynx, pharynx, trachea, esophagus, and thyroid, our knowledge about its involvement relies on few non-standardized data, due to the inadequate definition of this region.

METHOD

We propose an updated radiological and surgical definition of level VI, with the introduction of two sublevels which fulfill surgical, radiotherapy, radiological, and pathological concerns.

RESULTS

Level VIa encompasses prelaryngeal, intercricothyroidal, pretracheal, and perithyroidal nodes. Level VIb encompasses inferior laryngeal nodes. Within the traditional limits of level VI, all lymph nodes lying between the inferior border of the hyoid bone and the inferior border of the cricoid cartilage belong to level VIa. Between the inferior border of the cricoid cartilage and the top of the suprasternal notch, lymph nodes lying in front of the posterior face of the thyroid gland belong to level VIa; those lying behind this boundary belong to level VIb. We also discuss the definition of the superior mediastinal lymph nodes, which should not be mistaken for level VI.

Long-term results and functional outcome after cervical evisceration in patients with thyroid cancer

BACKGROUND

Surgical strategy in patients with thyroid cancer (TC) infiltrating the aerodigestive system is controversial. This study was undertaken to examine the long-term results of cervical evisceration (CE).

PATIENTS AND METHODS

Since 1995, 14 consecutive patients with advanced TC underwent total laryngectomy (LE, n = 6) or esophagolaryngectomy (ELR, n = 8). Patients with unusual thyroid neoplasms or metastases to the thyroid (n = 3) were excluded. For esophageal reconstruction, free jejunal grafts (n = 6) and gastric tubes (n = 2) were used.

RESULTS

Procedure-related morbidity and mortality were 42% and 14%, respectively. ELR was associated with a significant higher frequency of complications and reoperations compared with LE. Twelve-month and 30-month survival rates were 73% and 55%, respectively; 85% of the patients were satisfied with the surgical results. There were no long-term problems concerning food intake in the ELR patients. Two ELR patients were able to learn a substitutive voice.

CONCLUSIONS

Cervical evisceration in patients with TC is associated with significant perioperative morbidity and mortality requiring careful patient selection. Regarding long-term survival, local tumor control, and patient's satisfaction, however, CE should be taken into account in suitable patients with advanced TC.

Papillary thyroid cancer: surgical management of lymph node metastases

Papillary thyroid cancer (PTC), the most common thyroid malignancy, is associated with cervical lymph node metastases in 30% to 90% of patients. While surgery is the primary treatment modality for PTC, radioactive iodine and thyroid hormone suppression often complement the treatment plan. Although thyroid hormone suppression may decrease the incidence of recurrent disease and radioactive iodine may diagnose and treat metastases, lymph node dissection (LND) is the mainstay treatment for clinically evident cervical lymph node metastases. The surgical treatment options published in the literature include the traditional radical LND, the modified radical LND, the selective LND (compartment-based resection based on documented lymph node metastases), and a 'berry picking' resection (in which only the grossly abnormal lymph nodes are excised). At the University of California, San Francisco, we prefer the modified radical LND with preservation of the cervical sensory nerves for the first lymph node dissection with the 'berry picking' procedure limited to surgical treatment of recurrent nodal metastases in previously resected lymph node basins. Some centers are evaluating the potential role of sentinel lymph node biopsies for PTC. While the extent of lymphadenectomy is debated, most physicians treating patients with PTC agree that clinical evidence of lymphatic metastases should be surgically exercised and there is no role for prophylactic LND.

Contralateral cervical and mediastinal lymph node metastasis in medullary thyroid cancer: systemic disease?

BACKGROUND

The current American Joint Committee on Cancer/International Union Against Cancer classification designates cervical and mediastinal lymph nodes as regional lymph nodes. In a unilateral thyroid neoplasm, however, involvement of the contralateral cervical lymph node compartment or the mediastinal lymph node compartment, both of which have been designated "distant" lymph nodes, may serve as a surrogate parameter of distant metastases.

METHODS

This institutional series consisted of 105 consecutive patients with medullary thyroid cancer who underwent systematic dissections of both distant lymph node compartments.

RESULTS

Thirty-eight patients had no distant lymph node metastasis, 36 patients had involvement of only 1, and 31 patients of both distant lymph node compartments. Significant associations (P < .001) were seen on univariate analysis between the number of involved "distant" lymph node compartments (none, one, or both) and extrathyroidal extension (3%, 33%, and 58%), the number of positive lymph nodes (means of 3, 13, and 33), and distant metastasis (8%, 36%, and 61%). In a multivariate logistic regression model, only involvement of one or both "distant" lymph node compartments (versus no distant lymph node metastasis) remained significantly related to distant metastasis in a dose-dependent fashion.

CONCLUSIONS

"Distant" lymph nodes in medullary thyroid cancer should be regarded as nonregional lymph nodes because their involvement is indicative of distant metastasis.

Locally advanced differentiated thyroid carcinoma: a 35-year mono-institutional experience in 280 patients

AIM

Debate exists in the literature about the optimal treatment to be adopted in patients with locally advanced differentiated thyroid carcinoma. We aimed to better define the most appropriate diagnostic and therapeutic protocol for this type of tumour.

METHODS

The clinical and histopathological records of 280 consecutive patients with locally advanced differentiated thyroid carcinoma, studied and operated on by the same surgical team in the period between 1967 and 2002, were reviewed.

RESULTS

With regard to overall survival, at univariate statistical analysis, the patient's age at diagnosis (threshold, 45 years), primary tumour size, local cancer extension at diagnosis (subtypes of T4), extent of thyroidectomy, performance of lymph node dissection and performance of post-surgical external radiotherapy were found to be significant prognostic variables. With regard to the appearance of recurrent disease during follow-up, at univariate statistical analysis, the patient's age at initial diagnosis (threshold, 45 years), primary tumour size, local cancer extension at diagnosis (subtypes of T4), extent of thyroidectomy, performance of lymph node dissection, presence of metastatic lymph nodes, performance of post-surgical 131I therapy and performance of post-surgical external radiotherapy were found to be significant prognostic variables. At multivariate statistical analysis, the patient's age at initial diagnosis, extent of tumour, extent of thyroidectomy and performance of lymph node dissection were the only independent prognostic variables.

CONCLUSIONS

In our experience, an aggressive surgical approach at first diagnosis appears to offer a better prognosis in terms of both overall survival and disease-free time interval in patients with locally advanced differentiated thyroid carcinoma, especially those over 45 years of age.

Locally advanced thyroid cancer

PURPOSE OF REVIEW

The purpose of this review is to summarize existing literature with respect to locally advanced thyroid cancer and define the intricacies of preoperative evaluation, surgical management of involved sites and postoperative treatment.

RECENT FINDINGS

Locally invasive thyroid cancer is an uncommon disease process, which carries significant morbidity and mortality. Current treatment modalities include appropriate surgery, radioactive iodine treatment and external beam radiation therapy. Proper evaluation of the extent of disease, with complete gross tumor removal, is paramount in managing this difficult problem. Surgical treatment is still the mainstay for locally advanced thyroid cancer.

SUMMARY

Little progress has been made in advancing the treatment of locally advanced thyroid cancer. Patient identification, evaluation and proper surgical management with adjuvant therapy, still remain the most effective course of treatment. Aggressive surgical treatment including removal of all gross tumor and still preserving vital structures along with adjuvant therapy is likely to offer the best results. There is a very high incidence of locoregional and distant failure in this group of patients. The understanding and recognition of histopathological variations, such as poorly differentiated thyroid cancer is also important. New molecular markers are needed to help identify and predict aggressive tumor behavior.

Management of the locally aggressive thyroid carcinoma

The management of locally advanced thyroid carcinoma can be challenging. Differing philosophies exist for the treatment of invasive disease affecting the upper aerodigestive tract. The ability to maximize local control and overall survival while minimizing the morbidity of a radical resection is the goal of care in these patients. This article will review the literature concerning the presentation, preoperative evaluation, and the subsite treatment of locally aggressive well-differentiated thyroid carcinoma.