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

Prevalence of Central Compartment Lymph Node Metastases in Papillary Thyroid Micro-Carcinoma: A Retrospective Evaluation of Predictive Preoperative Features

Simple Summary

The present study focused on patients affected by stage pT1a papillary thyroid micro-carcinomas that were treated with surgery and central lymph node dissection. In this study, male sex, low age, and sub-capsular carcinoma localization resulted as independent predictive factors for central lymph node metastases.

Abstract

Papillary thyroid micro-carcinomas are considered relatively indolent carcinomas, often occult and incidental, with good prognosis and favorable outcomes. Despite these findings, central lymph node metastases are common, and are related to a poor prognosis for the patient. We performed a retrospective analysis on patients treated with surgery for stage pT1a papillary thyroid micro-carcinomas. One hundred ninety-five patients were included in the analyses. The presence of central lymph node metastases was identified and studied. A multivariate analysis employing binary logistic regression was used to calculate adjusted odds ratios with 95% confidence intervals of possible central lymph node metastases risk factors. In the performed multivariate analysis, male gender, younger age, and histopathological characteristics, such as a tumor sub-capsular localization, were significantly associated with central lymph node metastases in pT1a patients. Central compartment lymph node metastases are present in a non-negligible number of cases in patients with papillary thyroid micro-carcinoma undergoing surgical resection. Studying these factors could be an effective tool for predicting patients’ central lymph node metastases in papillary thyroid micro-carcinomas, defining a tailored surgical treatment in the future.

Sentinel Lymph Node Biopsy in Small Papillary Thyroid Cancer: A Meta-analysis

PURPOSE

The aim of this study was to compare reported results on available techniques for sentinel lymph node detection rate (SDR) in papillary thyroid cancer (PTC).

METHODS

The MEDLINE database was searched via a PubMed interface to identify original articles regarding sentinel lymph node biopsy (SNB) in thyroid cancer. Studies were stratified according to the sentinel lymph node (SLN) detection technique: vital-dye (VD), Tc-nanocolloid planar lymphoscintigraphy with the use of intraoperative hand-held gamma probes (LS), both Tc-nanocolloid planar lymphoscintigraphy with intraoperative use of hand-held gamma probe and VD (LS + VD), Tc-nanocolloid planar lymphoscintigraphy with the additional contribution of preoperative SPECT/CT, and intraoperative use of hand-held gamma probe (LS-SPECT/CT). Pooled SDR values were presented with a 95% confidence interval (CI) for each SLN detection techniques. A Z-test was used to compare pooled SDR estimates. False-negative rates were summarized for each method.

RESULTS

Forty-five studies were included. Overall SDRs for the VD, LS, LS + VD, and LS-SPECT/CT techniques were 83% (95% CI, 77%-88%; I = 78%), 96% (95% CI, 90%-98%; I = 68%), 87% (95% CI, 65%-96%; I = 75%), and 93% (95% CI, 86%-97%; I = 0%), respectively. False-negative rates were 0% to 38%, 0% to 40%, 0% to 17%, and 7% to 8%, respectively.

CONCLUSIONS

In patients with PTC, Tc-nanocolloids offer a higher SDR than that of the VD technique. The addition of SPECT/CT improved identification of metastatic SLNs outside the central neck compartment.

Risk factors for local recurrence following lateral neck dissection for papillary thyroid carcinoma

PURPOSE

We aimed to evaluate risk factors for local recurrence following lateral neck dissection (LND) for papillary thyroid carcinoma (PTC).

METHODS

Two hundred and nine patients who underwent therapeutic primary or reoperative LND for PTC were included.

RESULTS

One hundred eighty-one patients underwent primary LND at our Institution, the remaining 28 were referred for recurrence following LND outside the Institution. Comparing patients who required reoperation for recurrent lateral neck disease with those who did not recur, no significant difference was found concerning sex, tumor size, multifocal disease, extracapsular invasion, histological variant, pT stage (P = NS). At univariate analysis, age, mean number of removed lateral neck nodes at first operation, the extent of initial LND and surgery performed outside the Institution were risk factors for recurrence (P < 0.001).

CONCLUSIONS

Limited LND and surgery performed at non referral Centers were non tumor-related risk factors for recurrence following therapeutic LND for PTC.

Sentinel lymph node biopsy in small papillary thyroid cancer. A review on novel surgical techniques

PURPOSE

Sentinel lymph node biopsy (SNB) in patients with papillary thyroid carcinoma (PTC) and negative for clinically neck lymph node metastatic involvement (N0) has emerged as a promising minimally invasive procedure to detect metastatic nodes.

METHODS

The MEDLINE database was searched via the PubMed interface on 10 January 2018 for the MeSH headings "sentinel lymph node biopsy" and "thyroid carcinoma".

RESULTS

Vital blue dye, radioisotope, and the combination of both techniques are used in PTC patients. These methods and the emerging role of SPECT/CT are discussed in this review. The sentinel lymph node (SLN) identification rates ranged from 0 to 100% for blue dye, 83 to 100% for radioisotopes, and 66 to 100% for the combination of both techniques, respectively.

CONCLUSIONS

SNB based on radioisotope technique with the use of intraoperative gamma-probe is an accurate and safe method that allows the highest SLN detection rate. There is sufficient evidence to propagate the increasing use of SNB procedure that has the potential to avoid prophylactic lymph node surgery in patients clinically N0.

Dissection of Levels II Through V Is Required for Optimal Outcomes in Patients with Lateral Neck Lymph Node Metastasis from Papillary Thyroid Carcinoma

BACKGROUND

Completeness of surgical resection is an important determinant of outcomes in patients with papillary thyroid carcinoma and regional lymph node metastasis. The extent of therapeutic lateral neck dissection remains controversial. This study aims to assess the impact of modified radical neck dissection of levels II to V in a large patient series.

STUDY DESIGN

Retrospective analysis of consecutive patients with papillary thyroid carcinoma who underwent lateral neck dissection at a single institution from June 1, 2006 to December 31, 2014 was performed.

RESULTS

A total of 241 lateral neck dissections were performed in 191 patients (118 [62%] women; median age 46 years [range 6 to 87 years]; median follow-up 14.3 months [range 0.1 to 107 months]). Overall, 202 initial neck dissections (195 modified radical neck dissections and 7 less extensive dissections) were performed. Among these initial dissections, 137 (68.8%), 132 (65.7%), 105 (52.0%), and 33 (16.9%) had positive lymph nodes in levels II, III, IV, and V, respectively. Ipsilateral lymph node persistence or recurrence occurred after 22 (10.9%) initial dissections, at level II in 10 (45.5%), level III in 8 (36.4%), level IV in 7 (31.8%), and level V in 3 (13.6%). Thirty-nine reoperative lateral neck dissection were performed, including 18 cases of persistence and recurrence after our initial dissections. In reoperative dissections, positive lymph nodes were confirmed in levels II, III, IV, and V in 18 (46.2%), 10 (25.6%), 13 (33.3%), and 5 (12.8%) dissections, respectively. Temporary nerve injury occurred in 6 (3.0%) initial and 4 (10.3%) reoperative dissections, respectively. There were no permanent nerve injuries.

CONCLUSIONS

Omitting levels II and V during lateral neck dissection for papillary thyroid carcinoma potentially misses level II disease in two-thirds of patients and level V disease in one-fifth of patients. Formal modified radical neck dissection is necessary to avoid the morbidity of reoperative surgery.

Risk Factors for Nodal Metastasis in cN0 Papillary Thyroid Microcarcinoma

BACKGROUND

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

MATERIALS AND METHODS

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

RESULTS

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

CONCLUSIONS

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

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

Involvement of level IIb lymph node metastasis and dissection in thyroid cancer

Thyroid neoplasms are the most frequent neoplasm in the head and neck region. Most thyroid carcinomas are well-differentiated tumors of follicular cell origin. Thyroid papillary carcinoma (TPC) is the most common thyroid malignancy. It constitutes 60% to 90% of all the thyroid carcinomas and cervical lymph node metastases are commonly seen in these patients. Although cervical lymph node metastases are common in this cancer, the management and the prognostic role of lymph nodes in TPC remains controversial. In this paper we reviewed the currently available literature regarding the extent of lateral neck dissection in papillary thyroid carcinoma patients with lateral neck metastasis.

Surgery of lymph nodes in papillary thyroid cancer

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

Surgical management of the lateral neck compartment for metastatic thyroid cancer

PURPOSE OF REVIEW

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

RECENT FINDINGS

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

SUMMARY

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

In papillary thyroid cancer, preoperative central neck ultrasound detects only macroscopic surgical disease, but negative findings predict excellent long-term regional control and survival

BACKGROUND

Ultrasound (US) of the central neck compartment (CNC) is considered of limited sensitivity for nodal spread in papillary thyroid cancer (PTC); elective neck dissection is commonly advocated even in the absence of sonographic abnormalities. We hypothesized that US is an accurate predictor for long-term disease-free survival, regardless of the use of elective central neck dissection in patients with PTC.

METHODS

A retrospective chart review of 331 consecutive PTC patients treated with total thyroidectomy at M.D. Anderson Cancer Center between 1996 and 2003 was performed. Information retrieved included preoperative sonographic status of the CNC, surgical treatment of the neck, demographics, cancer staging, histopathological variables and use of adjuvant treatment. The endpoints for the study were nodal recurrence and survival.

RESULTS

There were 112 males and 219 females with a median age of 44 years (range 11-87). The median follow-up time for the series was 71.5 months (range 12.7-148.7). There were 151 (45.6%) patients with a T1, 58 (17.5%) with a T2, 70 (21.1%) with a T3, and 52 (15.7%) with a T4. Preoperative sonographic abnormalities were present in the CNC in 79 (23.9%) patients. During the surveillance period, 11 (3.2%) patients recurred in the central neck, with an average time for recurrence of 22.8 months. Advanced T stage (T3/T4) and abnormal US were independent prognostic factors for recurrence in the central neck (p=0.013 and p=0.005 respectively). There were 119 (35%) patients with a sonographically negative central compartment who underwent elective central neck dissection; 85 of them (71.4%) were found to be histopathologically N(+) while 34 (28.6%) were pN0. There were no differences in overall survival (p=0.32), disease specific survival (DSS; p=0.49), and recurrence-free survival (p=0.32) between these two groups. Preoperative US of the CNC was an age-independent predictor for overall survival (p<0.001), DSS (p=0.0097), and disease-free survival (p=0.0005) on bivariate Cox regression.

CONCLUSIONS

US of the central compartment is an age-independent predictor for survival and CNC recurrence-free survival in PTC. Prophylactic neck dissection of the central compartment does not improve long-term disease control, regardless of the histopathological status of the lymph nodes retrieved. Our findings emphasize the ability of US to clinically detect relevant nodal disease and support conservative management of the CNC in the absence of abnormal findings.

[Differentiated thyroid cancer -- 2009]

Three years ago continental guidelines were published referring management and follow-up of low risk thyroid cancer patients. The aim of this paper is to summarize the changes and new directions in this field. High risk patients require another protocol. Neck ultrasound plays important role in differential diagnosis and in detecting recurrences. Some new ultrasound techniques are discussed, too. FDG-PET can help to solve the problem of patients having negative scan and increased thyroglobulin level. In recent years there was an expansion of our knowledge about the pathomechanism of thyroid cancer. It appears that genetic alterations frequently play a key role in carcinogenesis. There are molecular methods that allow the detection of these genetic events in thyroid fine needle aspirations samples providing important information for diagnosis, management and prognosis. Instead of diagnostic whole body scanning the posttherapeutic scan became preferable but in high risk cases the diagnostic whole body scintigrams serve useful data. Primary therapy of thyroid cancer is an adequate surgery: total thyreoidectomy and, if necessary, lymph node dissection or limited surgery in selected cases. Nowadays radioguided surgery can help to improve the results. Radioiodine therapy (e.g. rest ablation) proved to be a safe and effective method to complete surgery. It can prevent relapses and results in longer survival. Thyroid hormone withdrawal or recombinant human thyrotropin stimulation can increase thyrotropin level before radioiodine treatment. These two methods have similar success rate of rest ablation but irradiation burden of blood is lower in the case of exogenous stimulation which avoids hypothyroid state and preserves quality of life. Since tumor cells fail to maintain the ability to perform physiological functions they undergo dedifferentiation. Therefore, an important aim is to reactivate some function of differentiated cells, e.g. iodine uptake, production of thyroperoxydase and thyroglobulin. Opportunities for this therapeutic effort are also mentioned. Restoration of iodine uptake enables radioisotope treatment. Until now there has been little interest in the development of new drugs for the treatment of thyroid cancer. However, advances in our understanding of tumor cell biology will lead to a paradigm shift in the therapy that is likely to benefit patients who have high risk disease and who do not almost have any therapeutic option. There are new drugs in clinical trials that appear to be more effective than earlier cytotoxic agents. Probably modern chemotherapy of advanced thyroid cancer will have significant results in the near future.

[Not Available]

L. Brunaud Thyroid cancers are the most common endocrine cancer. Cervical lymph node metastases are observed in 20 to 60% of patients with papillary thyroid cancer. In 2008, no prospective randomized study has defined whether prophylactic central neck dissection should be performed during initial surgery for papillary thyroid cancer. Prophylactic lymph node dissection remains controversial. Pros and cons for routine lymph node dissection of the central cervical compartment are discussed in this review of the literature which includes data from international and French consensus conferences.

[Not Available]

L. Brunaud Thyroid cancers are the most common endocrine cancer. Cervical lymph node metastases are observed in 20 to 60% of patients with papillary thyroid cancer. In 2008, no prospective randomized study has defined whether prophylactic central neck dissection should be performed during initial surgery for papillary thyroid cancer. Prophylactic lymph node dissection remains controversial. Pros and cons for routine lymph node dissection of the central cervical compartment are discussed in this review of the literature which includes data from international and French consensus conferences.

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.

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.

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.

Imaging for staging and management of thyroid cancer

The management of thyroid cancer has been controversial and, as a result, the routine use of imaging in this disease, especially for pre-operative staging, has lagged behind other head and neck cancers. However, as more is known about the natural history of thyroid cancer, the role of imaging is becoming more established. This review focuses on how imaging now influences the staging and management of the primary cancer, nodal metastases and distant metastases. This is followed by a brief review of the role of imaging in planning post-operative radiotherapy and post-treatment surveillance.

High frequency of level II-V lymph node involvement in RET/PTC positive papillary thyroid carcinoma

AIMS

To investigate the frequency and clinical significance of RET rearrangement in Chinese patients with papillary thyroid carcinoma (PTC) and discuss the role of RET rearrangement in therapeutic decision-making after the performance of level VI lymph node dissection and the 2002 AJCC staging system.

METHODS

RET/PTC-1 and RET/PTC-3 were detected in 126 PTCs using reverse transcription-polymerase chain reaction (RT-PCR) and direct sequencing.

RESULTS

RET rearrangement was detected in 18 cases of PTC. The patient group aged < 20 years had the highest frequency (3/6) of RET rearrangement among the age groups (< 20 years, 20-40 years and > or = 40 years; P=0.03). RET/PTC-1 positive patients were more likely to suffer from Hashimoto's thyroiditis simultaneously (P=0.02) while RET/PTC-3 positive patients had a higher frequency of extrathyroidal extension (P<0.01) and advanced T classification (P<0.01). RET rearrangement (OR=8.70, 95% CI 1.69-44.81), male (OR=3.88, 95% CI 1.41-10.69), age (OR=0.96, 95% CI 0.93-0.99), multifocality (OR=3.54, 95% CI 1.33-9.41) and advanced T classification (OR=7.32, 95% CI 2.91-18.40) were all identified as risk factors of level II-V lymph node involvement in the multivariate analysis.

CONCLUSIONS

The frequency of RET rearrangement in Chinese patients is low and age related. RET/PTC-1 and RET/PTC-3 are associated with different clinical pathological characteristics but not with lymph node involvement. The RET/PTC positive patients should receive more attention to lateral neck in the management of PTC.

Management of patients with low-risk papillary thyroid carcinoma

OBJECTIVE

To define a rational, cost-effective, simple approach to managing most patients with papillary thyroid cancer (PTC) who are at low-risk of either cause-specific mortality or tumor recurrence.

METHODS

Taking advantage of the collective experience of a cohort of 2512 patients with PTC who had initial definitive treatment at the Mayo Clinic in Rochester, Minnesota, between 1940 and 2000, a 5-step approach to the management of low-risk PTC has been devised. This program is based on appropriate preoperative ultrasound localization of neck disease and potentially curative surgery consisting of near-total or total thyroidectomy, with appropriate neck nodal exploration and resection.

RESULTS

The emphasis of the present program is on the extent of initial surgery, where optimal care is ascribed to a near-total thyroidectomy with curative intent and appropriate neck nodal resection as predicated by appropriate preoperative ultrasonography evaluation of regional lymph nodes. Radioiodine remnant ablation (RRA) is not applicable to patients with PTC who are defined on the day of definitive initial surgery to be at low risk as defined by a metastasis, age, completeness of resection, invasion, and size (MACIS) score of less than 6.

CONCLUSION

The outlook for patients with low-risk PTC is very optimistic, with rates at 30 postoperative years of only 1% for cause-specific mortality and less than 15% for tumor recurrence at any site. The long-term results obtained by potentially curative bilateral resection, appropriate regional lymph nodal excision, and selective use of RRA are excellent. Realistically improving these acceptably low rates for cause-specific mortality and tumor recurrence may be difficult.

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.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

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.