Clinical impact of cervical lymph node involvement and central neck dissection in patients with papillary thyroid carcinoma: a retrospective analysis of 368 cases

Lymph node metastasis and tumor-educated immune tolerance: Potential therapeutic targets against distant metastasis

Lymph node metastasis has been shown to positively associated with the prognosis of many cancers. However, in clinical treatment, lymphadenectomy is not always successful, suggesting that immune cells in the tumor and sentinel lymph nodes still play a pivotal role in tumor immunosuppression. Recent studies had shown that tumors can tolerate immune cells through multiple strategies, including tumor-induced macrophage reprogramming, T cells inactivation, production of B cells pathogenic antibodies and activation of regulatory T cells to promote tumor colonization, growth, and metastasis in lymph nodes. We reviewed the bidirectional effect of immune cells on anti-tumor or promotion of cancer cell metastasis during lymph node metastasis, and the mechanisms by which malignant cancer cells modify immune cells to create a more favorable environment for the growth and survival of cancer cells. Research and treatment strategies focusing on the immune system in lymph nodes and potential immune targets in lymph node metastasis were also be discussed.

Comparison of surgical strategies in the treatment of low-risk differentiated thyroid cancer

CONTEXT

Increasing diagnostic sensitivity in the detection of thyroid cancer has led to uncertainties in the optimal surgical approach of the smaller, low risk tumors. Current ATA guidelines consider lobectomy safe between 1 and 4 cm, while ETA advocates for primary total thyroidectomy to avoid reoperation, as final risk stratification is based on the histological results.

OBJECTIVE

Our aim was to compare the differences in outcomes that are potentially achievable with adherence to the different guidelines, and also to examine the predictive value of clinical parameters on the incidence of postoperative risk factors.

METHODS

We performed a retrospective cohort database analysis to identify the different surgical outcomes (based on postoperative risk factors) using ATA and ETA guidelines; the hypothetical rate of completion thyroidectomy when ATA or ETA recommends lobectomy; the accuracy of our preoperative evaluation; the utility of preoperative findings in predicting the optimal surgical strategy using binary logistic regression.

RESULTS

Out of 248 patients, 152 (ATA) and 23 (ETA) cases would have been recommended for initial lobectomy. Following the guidelines, a postoperative risk factor would have been present in 61.8, and 65.2% of the cases, respectively. Except for angioinvasion, tumor size was not a significant predictor for the presence of postoperative risk factors.

CONCLUSION

Current pre-operative criteria are inadequate to accurately determine the extent of initial surgery and our postoperative findings verify the frequent need for completion thyroidectomy using both guidelines. As a consequence, in the absence of effective pre-operative set of criteria, we advocate primary total thyroidectomy in most cases.

Log odds of negative lymph nodes/T stage ratio (LONT): A new prognostic tool for differentiated thyroid cancer without metastases in patients aged 55 and older

BACKGROUND

The optimal approach to assess the postoperative status of lymph nodes in differentiated thyroid cancer (DTC) remains controversial. Our aim was to determine if the log odds of negative lymph nodes/T stage ratio (LONT) could serve as a new prognostic and predictive tool for DTC without metastases in patients aged ≥ 55 years.

METHODS

The Surveillance, Epidemiology, and End Results (SEER) database was used to study the role of LONT in patients aged ≥55 years diagnosed with DTC without metastases. The primary outcome was overall survival (OS). The Kaplan-Meier method and the Cox proportional hazard regression model were used to calculate the outcome. Moreover, the robustness of research findings was evaluated using sensitivity analyses.

RESULTS

A total of 21,172 DTC patients aged ≥55 years without distant metastasis were enrolled. Multivariate Cox regression analyses and a "floating absolute risk" analysis showed that a LONT ≥0.920 (vs. -0.56 to 0.92) was a protective factor for OS in DTC patients. Sensitivity analyses revealed an E-value of 1.98 for the obtained LONT value. In subgroup analyses, LONT was correlated significantly with OS in different subgroups of negative lymph nodes, stage-I-II subgroups and the N0 subgroup. The conditional probability of survival of DTC improved with prolonged survival time in the LONT ≥0.920 group.

CONCLUSION

A high LONT was associated with longer OS compared with low LONT in patients aged ≥55 years with non-metastatic DTC. LONT could provide valuable information for undertaking postoperative evaluations.

Reprogramming of sentinel lymph node microenvironment during tumor metastasis

Metastasis is a major cause of death in patients with cancer. The two main routes for cancer cell dissemination are the blood and lymphatic systems. The underlying mechanism of hematogenous metastasis has been well characterized in the past few decades. However, our understanding of the molecular basis of lymphatic metastasis remains at a premature stage. Conceptually, cancer cells invade into lymphatic capillary, passively move to collecting lymphatic vessels, migrate into sentinel lymph node (SLN;, the first lymph node to which cancer cells spread from the primary tumor), and enter the blood circulatory system via the subclavian vein. Before arriving, cancer cells release specific soluble factors to modulate the microenvironment in SLN to establish a beachhead for successful colonization. After colonization, cancer cells inhibit anti-tumor immunity by inducing the recruitment of regulatory T cell and myeloid-derived suppressor cells, suppressing the function of dendritic cell and CD8⁺ T cell, and promoting the release of immunosuppressive cytokines. The development of novel strategies to reverse cancer cell-triggered SLN remodeling may re-activate immunity to reduce beachhead buildup and distant metastasis. In addition to being a microanatomic location for metastasis, the SLN is also an important site for immune modulation. Nanotechnology-based approaches to deliver lymph node-tropic antibodies or drug-conjugated nanoparticles to kill cancer cells on site are a new direction for cancer treatment. Conversely, the induction of stronger immunity by promoting antigen presentation in lymph nodes provides an alternate way to enhance the efficacy of immune checkpoint therapy and cancer vaccine. In this review article, we summarize recent findings on the reprogramming of SLN during lymphatic invasion and discuss the possibility of inhibiting tumor metastasis and eliciting anti-tumor immunity by targeting SLN.

Is total thyroidectomy with bilateral central neck dissection the only surgery for papillary thyroid carcinoma patients with clinically involved central nodes?

Background

In clinical practice, we often observed that patients who underwent total thyroidectomy due to clinically involved nodal disease (cN1a) actually had less extensive CLNM on final pathology. This study investigates whether total thyroidectomy and therapeutic bilateral CND are necessary for all PTC patients with cN1a.

Methods

This study retrospectively reviewed 899 PTC patients who underwent total thyroidectomy with bilateral CND from January 2012 to June 2017. The patients were divided into two groups according to pre-operative central lymph node (CLN) status: cN0, no suspicious CLNM; cN1a, suspicious CLNM. We compared the clinicopathological features of these two groups.

Results

There was no significant difference in recurrence between cN0 and cN1a groups after a mean follow-up time of 59.1 months. Unilateral cN1a was related to the largest central LN size ≥ 2 mm (OR = 3.67, p < 0.001) and number of CLNM > 5(OR = 2.24, p = 0.006). On the other hand, unilateral cN1a was not associated with an increased risk of contralateral lobe involvement (OR = 1.35, p = 0.364) and contralateral CLNM (OR = 1.31, p = 0.359). Among 106 unilateral cN1a patients, 33 (31.1%) were found to be pN0 or had ≤ 5 metastatic CLNs with the largest node smaller than 2 mm.

Conclusions

Most cN1a patients were in an intermediate risk group for recurrence and required total thyroidectomy. However, lobectomy with CND should have performed in approximately 30% of the cN1a patients. Pre-operative clinical examination, meticulous radiologic evaluation, and intra-operative frozen sections to check the nodal status are prerequisites for this approach.

Tumor-draining lymph nodes: At the crossroads of metastasis and immunity

Early engagement of the lymphatic system by solid tumors in peripheral, nonlymphoid tissues is a clinical hallmark of cancer and often forecasts poor prognosis. The significance of lymph node metastasis for distant spread, however, has been questioned by large-scale lymph node dissection trials and the likely prevalence of direct hematogenous metastasis. Still, an emerging appreciation for the immunological role of the tumor-draining lymph node has renewed interest in its basic biology, role in metastatic progression, antitumor immunity, and patient outcomes. In this review, we discuss our current understanding of the early mechanisms through which tumors engage lymphatic transport and condition tumor-draining lymph nodes, the significance of these changes for both metastasis and immunity, and potential implications of the tumor-draining lymph node for immunotherapy.

Management of the Neck in Well-Differentiated Thyroid Cancer

PURPOSE OF REVIEW

In this narrative review, we discuss the indications for elective and therapeutic neck dissections and the postoperative surveillance and treatment options for recurrent nodal disease in patients with well-differentiated thyroid cancer.

RECENT FINDINGS

Increased availability of advanced imaging modalities has led to an increased detection rate of previously occult nodal disease in thyroid cancer. Nodal metastases are more common in young patients, large primary tumors, specific genotypes, and certain histological types. While clinically evident nodal disease in the lateral neck compartments has a significant oncological impact, particularly in the older age group, microscopic metastases to the central or the lateral neck in well-differentiated thyroid cancer do not significantly affect outcome. As patients with clinically evident nodal disease are associated with worse outcomes, they should be treated surgically in order to reduce rates of regional recurrence and improve survival. The benefit of elective neck dissection remains unverified as the impact of microscopic disease on outcomes is not significant.

Para-tracheal neck dissection - is dissection of the upper part of level Ⅵ necessary?

Papillary thyroid carcinoma (PTC) has a high propensity for regional metastases, however, the impact of such metastases on the outcome of the patients is minimal. The central compartment of the neck is considered the first and the most common echelon of metastases from thyroid carcinoma. Physical examination along with ultrasonography are the gold standard pre-operative evaluation of patients with PTC. Ultrasonography is highly sensitive in evaluating lateral neck nodes, however, its value in evaluating the central compartment is limited, resulting in a relatively high rate of occult metastases in this compartment. The main potential complications of para-tracheal neck dissection (PTND) are recurrent laryngeal nerve paralysis and hypocalcemia and these may be higher in patients undergoing PTND compared to thyroidectomy alone. New histological data is available showing no evidence of lymph nodes in the central compartment above a level parallel to the inferior border of the cricoid cartilage. These findings support withholding dissection of the upper para-tracheal region routinely as a part of PTND in patients with well-differentiated thyroid cancer. By doing that, the complications may be lower and identical to thyroidectomy alone, thus may abolish arguments against more common use of elective PTND in patients with thyroid carcinoma.

Prediction mode of more than 5 central lymph nodes metastases in clinically node-negative ipsilateral papillary thyroid carcinoma with tumor size 1 to 4 cm

According to the 2015 American Thyroid Association guidelines, either lobectomy or total thyroidectomy was recommended for patients with papillary thyroid carcinoma (PTC) of 1 to 4 cm without extrathyroidal extension and lymph node metastasis. However, lymph node metastases showed strong association with recurrence and low survival rate, especially in PTC patients with more than 5 metastatic lymph nodes. Therefore, this study aimed to investigate the predictive factors of more than 5 central lymph nodes metastases (CLNM) in PTC patients with tumor sizes of 1 to 4 cm. A total of 382 patients with clinically node-negative (cN0) ipsilateral PTC who underwent thyroidectomy with central neck dissection between January 2012 and December 2016 were retrospectively analyzed. CLNMs of >5 were found in 54 (14.1%) patients, while CLNM was detected in 230 (60.2%) patients. Multivariate logistic regression revealed age < 45 years (P < .001), male gender (P = .013), and tumor sizes of >2 cm (P = .001) as independent predictive factors of >5 CLNMs in cN0 ipsilateral PTC patients with tumor sizes 1 to 4 cm. The prediction equation (Y = 1.694 × age + 0.807 × gender + 1.190 × tumor size - 3.530) was developed, with a sensitivity (57.4%) and a specificity (80.8%), respectively, at an optimal cut-off point of -1.685. Therefore, if the predictive value was higher than -1.685 according to the equation in cN0 ipsilateral PTC patients with tumor sizes 1 to 4 cm, then total thyroidectomy might be considered.

Randomized trial of prophylactic ipsilateral central lymph node dissection in patients with clinically node negative papillary thyroid microcarcinoma

PURPOSE

This study aimed to evaluate the role of prophylactic ipsilateral central neck dissection (pCND) in patients with clinically node-negative (cN0) papillary thyroid microcarcinoma (PTMC).

METHODS

In this randomized control trial, a total of 164 consecutive patients were enrolled. By double-blinded randomization protocol, patients were allocated into hemithyroidectomy with pCND (n = 82) or without pCND (n = 82). With intention-to-treat analysis, post-surgical pathological and clinical course, surgery-related complications, causes and clinical course of protocol-violated cases and 5-year recurrence-free survival were compared.

RESULTS

Operation time, hospital stay, and post-surgical complication were not significantly different between the two groups. In the pCND (+) group, occult lymph node metastasis rate was 50.0%, and lymph node ratio (metastatic/harvested lymph nodes) was 45.2%. Ten patients in the pCND (+) group had converted to undergo onsite or staged completion total thyroidectomy due to the presence of metastatic central lymph nodes and/or positive resection margin. Until last follow-up (mean 73.4 months), one regional recurrence developed in the pCND (-) group, and three regional recurrences occurred in the pCND (+) group. Five-year recurrence-free survival was similar between the two groups.

CONCLUSION

Although ipsilateral pCND could clear occult lymph node metastasis in the central compartment, it failed to provide any oncological benefit for cN0 PTMC patients.

Predictive factors for non-small-volume central lymph node metastases (more than 5 or ≥ 2 mm) in clinically node-negative papillary thyroid carcinoma

The benefits of prophylactic central neck dissection (pCND) for treating patients with clinical node-negative (cN0) papillary thyroid carcinoma (PTC) remain controversial. Lymph node metastases have been strongly associated with local recurrence and low survival, especially in PTC patients with 5 or more or ≥2 mm metastatic lymph nodes. The following study investigates the incidence and risk factors of more than 5 or ≥2 mm metastatic lymph nodes in the central compartment.A total of 611 patients with cN0 PTC were retrospectively analyzed. Cervical lymph nodes were harvested, and the size of metastatic lymph nodes was consequently analyzed.Non-small-volume central lymph node metastases (NSVCLNM), defined as more than 5 or ≥2 mm metastatic lymph nodes) were detected in 67 (11.0%) patients. Male gender, age ≤36 years, multifocal lesions, extrathyroidal extension, and tumor size > 0.85 cm were independent risk factors for NSVCLNM in cN0 PTC. The sensitivity and specificity of having ≥3 risk factors for predicting NSVCLNM was 46.3% and 86.8%, respectively.These findings suggest that pCND is a suitable treatment strategy for cN0 PTC patients with 3 or more risk factors for NSVCLNM.

Mapping the distribution of nodal metastases in papillary thyroid carcinoma: Where exactly are the nodes?

OBJECTIVE

To characterize nodal disease of patients presenting with papillary thyroid carcinoma (PTC) STUDY DESIGN: Retrospective chart review.

METHODS

PTC patients who underwent thyroidectomy and/or neck dissection (revision/primary) from 2004 to 2009 at a tertiary-care hospital were reviewed. Preoperative computed tomography (CT) scan and ultrasonography were utilized to identify macroscopic, clinically apparent nodal metastasis (cN+). Demographic data, type of surgery, nodal disease, and primary tumor information were recorded.

RESULTS

Of 416 patients reviewed, 35% had cN+ on initial presentation (IP); of these, 88% and 50% had central (CND) and lateral nodal disease (LND), respectively. The presence of ectopic nodal (END) metastases (nodal disease outside typical CND or LND locations) was absent on IP but occurred in 9% of patients with nodal recurrence. END was typically found in the retropharyngeal area but also was noted in the sublingual region, subcutaneous location, axilla, and chest wall. Extrathyroidal extension (ETE) was found in 8.9% without nodal disease, 33.1% with nodal disease, and 57.1% with END (P < 0.0001). Primary tumor size greater than 4 cm (P = 0.05) was associated with nodal disease.

CONCLUSION

This report represents a large series describing characteristics of the primary PTC tumor and associated nodal disease not only in the central and lateral neck but also in the ectopic locations. Our results suggest that a significant proportion of patients will have nodal disease in the central compartment on IP, especially younger patients. ETE and tumor size are associated with macroscopic nodal disease (including END). Nine percent of the patients with nodal recurrence had ectopic nodes occurring in various locations, most commonly in the retropharynx. CT scan can assist with identification and surgical planning of recurrent nodal disease.

LEVEL OF EVIDENCE

4. Laryngoscope, 127:1959-1964, 2017.

Differentiated and Medullary Thyroid Cancer: Surgical Management of Cervical Lymph Nodes

Thyroid cancer metastasises to the central and lateral compartments of the neck frequently and early. The impact of nodal metastases on outcome is affected by the histological subtype of the primary tumour and the patient's age, as well as the size, number and location of those metastases. The impact of extranodal extension has recently been highlighted as an important prognosticating factor. Although clinically evident nodal disease in the lateral neck compartments has a significant impact on both survival and recurrence, microscopic metastases to the central or the lateral neck in well-differentiated thyroid cancer do not significantly affect outcome. Here we discuss the surgical management of neck metastases in well-differentiated and medullary thyroid carcinoma.

Pattern of neck recurrence after lateral neck dissection for cervical metastases in papillary thyroid cancer

BACKGROUND

The objective of this study was to determine the rate and pattern of nodal recurrence in patients who underwent a therapeutic, lateral neck dissection (LND) for papillary thyroid cancer (PTC) with clinically evident cervical metastases and to determine if there was any correlation between the extent of initial dissection and the rate and pattern of neck recurrence.

METHODS

A total of 3,664 patients with PTC treated between 1986 and 2010 at Memorial Sloan Kettering Cancer Center were identified from our institutional database. Tumor factors, patient demographics, extent of initial LND, and adjuvant therapy were recorded. Patterns of recurrent lateral neck metastases by level involvement were recorded and outcomes calculated using the Kaplan-Meier method.

RESULTS

A total of 484 patients had an LND for cervical metastases; 364 (75%) had a comprehensive LND (CLND) and 120 (25%) had a selective neck dissection (SND). The median duration of follow-up was 63.5 months. As expected, patients with CLND had a greater number of nodes removed as well as a greater number of positive nodes (P < .001). There was no difference in overall lateral neck recurrence-free status (CLND 94.4% vs SND 89.4%, P = .158), but in the dissected neck, the ipsilateral lateral neck recurrence-free status was superior in the CLND patients (97.7% vs 89.4%, P < .001).

CONCLUSION

Patients with clinically evident neck metastases from PTC managed by CLND have lesser rates of recurrence in the dissected neck compared with patients managed by SND. SND should only be done in highly selected cases with small volume disease.

Outcomes for patients with papillary thyroid cancer who do not undergo prophylactic central neck dissection

BACKGROUND

The role of prophylactic central neck dissection (CND) in the management of papillary thyroid cancer (PTC) is controversial. This report describes outcomes of an observational approach in patients without clinical evidence of nodal disease in PTC.

METHODS

All patients who had surgery between 1986 and 2010 without CND for PTC were identified. All patients had careful clinical assessment of the central neck during preoperative and perioperative evaluation, with any suspicious nodal tissue excised for analysis. The cohort included patients in whom lymph nodes had been removed, but no patient had undergone a formal neck dissection. Recurrence-free survival (RFS), central neck RFS and disease-specific survival (DSS) were calculated using the Kaplan-Meier method.

RESULTS

Of 1798 patients, 397 (22.1 per cent) were men, 1088 (60.5 per cent) were aged 45 years or more, and 539 (30.0 per cent) had pT3 or pT4 disease. Some 742 patients (41.3 per cent) received adjuvant treatment with radioactive iodine. At a median follow-up of 46 months the 5-year DSS rate was 100 per cent. Five-year RFS and central neck RFS rates were 96.6 and 99.1 per cent respectively.

CONCLUSION

Observation of the central neck is safe and should be recommended for all patients with PTC considered before and during surgery to be free of central neck metastasis.

The Clinicopathological Features of BRAF Mutated Papillary Thyroid Cancers in Chinese Patients

The BRAF(V600E) mutation is commonly found in papillary thyroid cancers (PTCs) at different frequencies in different regions. However, the association between the BRAF(V600E) mutation and clinicopathological features in Chinese PTC patients is unknown. A total of 543 Chinese patients with histologically confirmed PTC were enrolled in this study. For the BRAF mutation assay, the target fragments were amplified and sequenced with an ABI 3500 gene analyzer. In 170 of 543 samples (31.3%), the BRAF(V600E) mutation was detected. In the bivariate analysis, the BRAF(V600E) mutation showed an association with bilaterality, tumor size, extrathyroidal invasion, and lymph node metastases (LNM). However, in the multivariate analysis, the BRAF(V600E) mutation was positively related to only tumor size (>1 cm) and extrathyroidal invasion. In addition, the multivariate analysis also showed that the age at diagnosis (<45 y) and tumor size (>1 cm) were independent predictors for LNM. In this study, the BRAF(V600E) mutation is positively associated with worse prognostic factors, including larger tumor size and the tumor extending to the thyroid capsule or extrathyroidal region; however, it is not an independent predictor for LNM.

Long-term outcomes of observation for clinically negative central compartment lymph nodes in papillary thyroid carcinoma

The treatment strategy for clinically negative lymph nodes of papillary thyroid carcinoma is controversial. We report the long-term outcomes of a series of cases treated with thyroidectomy without prophylactic central neck dissection. We reviewed 1,397 cases with papillary thyroid carcinoma treated at our institution between 1991 and 2000. One hundred and seventy-two newly diagnosed cases underwent observation for cN0 central neck lymph nodes. Regional recurrence of the ipsilateral side including central compartment and the lateral neck which needs reoperation was considered as key point for analysis. With a mean follow-up of 96.4 months (34-204 months), the overall 10-year disease-specific and recurrence-free survival rates were 99 and 86 %, respectively. The recurrence and reoperation rates of the central compartment were 3 % (5/172) and 4 % (7/172), respectively. Univariate analysis showed that extrathyroidal extension was associated with regional recurrence (99 vs. 82 %; p = 0.002). Central compartment observation is safe in cN0 cases with papillary thyroid carcinoma, particularly in those without extrathyroidal extension.

Severe Vitamin D Deficiency

Objective

To assess the role of preoperative serum 25 hydroxyvitamin D as predictor of hypocalcemia after total thyroidectomy.

Study Design

Retrospective cohort study.

Setting

University teaching hospital.

Subjects and Methods

All consecutively performed total and completion thyroidectomies from February 2007 to December 2013 were reviewed through a hospital database and patient charts. The relationship between postthyroidectomy laboratory hypocalcemia (serum calcium ≤2 mmol/L), clinical hypocalcemia, and preoperative serum 25 hydroxyvitamin D level was evaluated.

Results

Two hundred thirteen patients were analyzed. The incidence of postoperative laboratory and clinical hypocalcemia was 19.7% and 17.8%, respectively. The incidence of laboratory and clinical hypocalcemia among severely deficient (<25 nmol/L), deficient (<50 nmol/L), insufficient (<75 nmol/L), and sufficient (≥75 nmol/L) serum 25 hydroxyvitamin D levels was 54% versus 33.9%, 10% versus 18%, 2.9% versus 11.6%, and 3.1% versus 0%, respectively. Multiple logistic regression analysis revealed preoperative severe vitamin D deficiency as a significant independent predictor of postoperative hypocalcemia (odds ratio [OR], 7.3; 95% confidence interval [CI], 2.3-22.9; P = .001). Parathyroid hormone level was also found to be an independent predictor of postoperative hypocalcemia (OR, 0.6; 95% CI, 0.5-0.8; P = .002).

Conclusion

Postoperative clinical and laboratory hypocalcemia is significantly associated with low levels of serum 25 hydroxyvitamin D. Our findings identify severe vitamin D deficiency (<25 nmol/L) as an independent predictor of postoperative laboratory hypocalcemia. Early identification and management of patients at risk may reduce morbidity and costs.

Is outcome of differentiated thyroid carcinoma influenced by tumor stage at diagnosis?

BACKGROUND

There is no international consensus on surveillance strategies for differentiated thyroid carcinoma (DTC) after radiotherapy for childhood cancer. Ultrasonography could allow for early detection of DTC, however, its value is yet unclear since the prognosis of DTC is excellent. We addressed the evidence for the question: 'is outcome of DTC influenced by tumor stage at diagnosis?'.

METHODS

A multidisciplinary working group answered the sub-questions: 'is recurrence or mortality influenced by DTC stage at diagnosis? Does detection of DTC at an early stage contribute to a decline in adverse events of treatment?' The literature was systematically reviewed, and conclusions were drawn based on the level of evidence (A: high, B: moderate to low, C: very low).

RESULTS

In children, level C evidence was found that detection of DTC at an early stage is associated with lower recurrence and mortality rates. No evidence was found that it influences morbidity rates. In adults, clear evidence was found that less advanced staged DTC is a favorable prognostic factor for recurrence (level B) and mortality (level A). Additionally, it was found that more extensive surgery increases the risk to develop transient hypoparathyroidism (level A) and that higher doses of radioiodine increases the risk to develop second primary malignancies (level B).

CONCLUSION

Identification of DTC at an early stage is beneficial for children (very low level evidence) and adults (moderate to high level evidence), even considering that the overall outcome is excellent. These results are an important cornerstone for the development of guidelines for childhood cancer survivors at risk for DTC.

Copper as ancillary diagnostic tool in preoperative evaluation of possible papillary thyroid carcinoma in patients with benign thyroid disease

Preoperative diagnosis of papillary thyroid carcinoma (PTC) comprises numerous diagnostic procedures which are mostly applicable in tertiary institutions. Normal thyroid function depends on the presence of many trace elements and copper (Cu) and zinc (Zn) are some of those. The study is based on retrospective review of 118 patients with preoperatively diagnosed benign thyroid disease (BTD) and 12 with PTC, who underwent thyroid surgery at the Center for Endocrine Surgery Clinical Center of Serbia, Belgrade, between 2010 and 2012. The objective was to evaluate concentrations of Cu and Zn in serum as possible prediction markers for PTC in patients who underwent surgery for preoperatively diagnosed BTD. Concentrations of Cu and Zn ions in serum were measured using atomic absorption spectrophotometer. Data were analyzed using methods of descriptive statistics, Anova and t-test (p < 0.05 was considered statistically significant). Definitive pathohistological findings revealed PTC in 23 (19.5%) and papillary microcarcinoma-mPTC in 13 (11.0%) of BTD patients. The concentrations of Cu ions in serum of PTC patients as well as in serum of patients with mPTC were significantly higher than in serum of BTD patients (p < 0.05). The concentrations of Zn ions and Cu/Zn ratio in serum of PTC and mPTC patients were not significantly higher than in serum of BTD patients. The concentration of Cu ions in serum of patients before thyroid surgery can be useful, easy available, and a low-cost tool in prediction of preoperatively undiagnosed PTC in patients with BTD.

Differentiated thyroid cancer-personalized therapies to prevent overtreatment

The concept of individualized therapy is rapidly gaining recognition in the management of patients with differentiated thyroid cancer (DTC). This Review provides an overview of the most important elements of this paradigm shift in DTC management and discusses the implications for clinical practice. In the majority of patients with DTC who have an inherently good prognosis, the extent of surgery, the dosage of (131)I therapy and the use of levothyroxine therapy are all aspects suitable for individualization, on the basis of both the stage of disease and the response to treatment. In individuals with advanced disease, newer imaging techniques, advances in (131)I therapy and the use of targeted molecular therapies (such as multitargeted kinase inhibitors) have provided new options for the personalized care of patients, for whom until recently no effective therapies were available. Individualized therapies could reduce adverse effects, including the sometimes debilitating hypothyroidism that used to be required before initiation of (131)I treatment, and major salivary gland damage, a common and unpleasant side effect of (131)I therapy. Highly individualized interdisciplinary treatment of patients with DTC might lead to improved outcomes with reduced severity and frequency of complications and adverse effects. However, in spite of ongoing research, personalized therapies remain in their infancy.

Risk factors of central lymph node metastasis in cN0 papillary thyroid carcinoma: a study of 529 patients

Background

Lymph node metastasis in papillary thyroid carcinoma (PTC) is common; however, the need for prophylactic central lymph node dissection (CLND) in PTC is still controversial. The objective of this study was to investigate the risk factors of central lymph node metastasis (CLNM) in clinically lymph node-negative (cN0) PTC patients.

Material/Methods

A total of 529 cN0 PTC patients who underwent lobectomy plus isthmusectomy or total thyroidectomy with unilateral or bilateral CLND between 2010 and 2012 were enrolled in this study. Clinicopathologic risk factors for CLNM were studied using univariate and multivariate analysis.

Results

CLNM was found in 238 (45.0%) cases. In univariate analysis, male sex, age <45 years, tumor size >2 cm, tumor located in the middle/lower third of lobe, and multifocality were significantly associated with CLNM (P<0.05); extrathyroid extension, Hashimoto’s thyroiditis, and TSH value were not associated with CLNM. In multivariate analysis, tumor size >2 cm, age <45 years, multifocality, and tumor located in the middle/lower third of the lobe were independent predictors for CLNM.

Conclusions

Prophylactic CLND should be considered in cN0 PTC patients with the following risk factors: tumor size >2 cm, age <45 years, multifocality, or tumor located in the middle/lower third of the lobe. However, further long-term follow-up studies and multicenter research are needed to better understand these risk factors and the significance of prophylactic CLND.

Observation of clinically negative central compartment lymph nodes in papillary thyroid carcinoma

BACKGROUND

The role of prophylactic central neck dissection in the management of papillary thyroid cancer (PTC) is controversial. We report our experience of an observational approach to the cN0 neck in PTC.

METHODS

We reviewed 1,129 patients with PTC who had total thyroidectomy between 1986 and 2005. In that group, 470 patients were pN1; 384 had benign nodes removed (pN0); and the remaining 275 had no nodes removed (pNx). The pNx group formed the cohort for this study.

RESULTS

With a median follow-up of 70 months, the 10-yr disease-specific survival was 100%. We found 4 patients who had evidence of radioactive iodine uptake on scans performed during follow-up without diagnostic cytology. All subsequently received radioactive iodine and are considered disease free. Three patients had biopsy-proven lateral-neck recurrence and underwent neck dissection; 1 patient developed a low-level thyroglobulin suspicious for recurrence; and 1 patient had a subcentimeter level VI node suspicious for recurrence, which has been observed. Therefore, the rate of structural recurrence in the central neck was 0.4% (1/275), and the rate of reoperation on the central neck was 0.

CONCLUSION

Our results suggest that properly selected patients can be managed safely with observation of the central neck rather than prophylactic central neck dissection, which has a higher complication rate.

Prognostic value of the BRAF V600E mutation in papillary thyroid carcinoma

The aim of the present study was to investigate the prevalence of the BRAF V600E mutation in papillary thyroid carcinoma (PTC) and to determine the correlation between this mutation and indicators of poor prognosis and outcome in patients with PTC. The BRAF V600E mutation status was analyzed in 187 tumor samples using the multiplex allele-specific PCR method. Univariate and multivariate analyses were performed to investigate the association of the BRAF V600E mutation with clinical features and patient outcome. The sensitivity of the multiplex allele-specific PCR combined with denaturing high-performance liquid chromatography reached ~1%. The BRAF V600E mutation was observed in 63.6% (119/187) of tumor tissues, predominantly in PTC specimens, and no BRAF mutation was identified in other benign-type thyroid diseases. The univariate analysis indicated that the BRAF V600E mutation was associated with age, tumor stage and prognosis (P<0.05). In addition, the frequency of the BRAF V600E mutation was significantly different in the central (75.3%) and lateral neck (49.3%) lymph nodes of patients with lymph node metastasis. Multivariate logistic regression analysis showed that the BRAF V600E mutation (HR, 2.471; 95% CI, 1.149–5.312) and lymph node metastasis (HR, 3.003; 95% CI, 1.027–8.771) are independent factors that predict tumor prognosis. Thus, the BRAF V600E mutation is an independent risk factor that may be used to predict thyroid cancer persistence/recurrence.

Hypocalcemia after total laryngectomy: incidence and risk factors

OBJECTIVES/HYPOTHESIS

Hypocalcemia is common in the initial period after total laryngectomy. The purpose of the present study was to study the incidence of and risk factors for postlaryngectomy hypocalcemia at our institution.

STUDY DESIGN

Retrospective review of 65 consecutive total laryngectomies.

METHODS

Clinical data and calcium levels for the first postoperative week were collected. Biochemical hypocalcemia was defined as any corrected calcium level of < 2.0 mmol/l in the first postoperative week. Severe hypocalcemia was defined as a calcium of < 1.8 mmol/l, or symptoms of hypocalcemia. Risk factors for hypocalcemia were studied.

RESULTS

Five cases were excluded due to concomitant abdominal surgery (3), preoperative hypocalcemia (1), and no postoperative calcium levels (1). A total of 43% of patients had postoperative biochemical hypocalcemia. On univariate analysis, bilateral neck dissection was significant for hypocalcemia (P = 0.02), with pT4 classification having borderline significance (P = 0.07). On multivariate analysis, bilateral neck dissection (P = 0.02) and salvage surgery were significant (P = 0.03), with pT4 stage again having borderline significance (P = 0.05). Extent of thyroidectomy, extent of pharyngectomy, and preoperative tracheostomy were not significant. Fifteen patients (25%) had severe hypocalcemia. There were no significant risk factors for severe hypocalcemia identified.

CONCLUSIONS

Hypocalcemia is common after total laryngectomy, particularly in the postradiotherapy setting and in patients undergoing bilateral neck dissection. Preservation of one thyroid lobe does not appear to significantly reduce the risk.

A systematic review and meta-analysis of prophylactic central neck dissection on short-term locoregional recurrence in papillary thyroid carcinoma after total thyroidectomy

BACKGROUND

Prophylactic central neck dissection (pCND) at the time of total thyroidectomy (TT) remains controversial in clinically node-negative (cN0) papillary thyroid carcinoma (PTC). Despite occult central lymph node metastases being common, it is unclear if removing these metastases initially would reduce future locoregional recurrence (LRR). This systematic review and meta-analysis aimed at comparing the short-term LRR between patients who underwent TT with pCND and those who underwent TT alone.

METHODS

A systematic review of the literature was performed to identify studies comparing LRR between patients with PTC who underwent TT + pCND (group A) and those who underwent TT alone (group B). Inclusion criteria were cN0 patients, with each comparative group containing > 10 patients, and with the number of LRR and mean follow-up duration available. The pooled incidence rate ratio (IRR) was used for calculating the LRR rate between the two groups. Other parameters evaluated included postoperative radioiodine (RAI) ablation, surgically related complications, and overall morbidity. Meta-analysis was performed using a fixed-effects model.

RESULTS

Fourteen studies matched the selection criteria. Of the 3331 patients, 1592 (47.8%) belonged to group A, while 1739 (52.2%) belonged to group B. Relative to group B, group A was significantly more likely to have postoperative RAI ablation (71.7% vs. 53.1%; odds ratio [OR] = 2.60 [95% confidence interval (CI) = 2.12-3.18]), temporary hypocalcemia (26.0% vs. 10.8%; OR = 2.56 [CI = 2.04-3.21]), and overall morbidity (33.2% vs. 17.7%; OR = 2.12 [CI = 1.75-2.57]). When temporary hypocalcemia was excluded, overall morbidity was similar between the two groups (7.3% vs. 6.8%; OR = 1.07 [CI = 0.78-1.47]). Group A had a significantly lower risk of LRR than group B (4.7% vs. 8.6%; IRR = 0.65 [CI = 0.48-0.86]).

CONCLUSIONS

Group A was more likely to have postoperative RAI ablation, temporary hypocalcemia, and overall morbidity than group B. Temporary hypocalcemia was the major surgical morbidity in pCND and, when excluded, the overall morbidity appeared similar between the two groups. Although our meta-analysis would suggest that those who undergo TT + pCND may have a 35% reduction in risk of LRR than those who undergo TT alone in the short term (< 5 years), it remains unclear how much of this risk reduction is related to increased use of RAI ablation and potential selection bias in some of the studies examined.

Is systematic identification of all four parathyroid glands necessary during total thyroidectomy?: a prospective study

OBJECTIVES/HYPOTHESIS

Routine identification of all four parathyroid glands has been advocated as a means of reducing rates of postoperative hypocalcemia and inadvertent parathyroidectomy. The object of the present study was to investigate whether identification of more parathyroid glands during thyroidectomy performed by capsular dissection technique had any impact on incidence of postoperative hypocalcemia and unintentional parathyroid resection.

STUDY DESIGN

Prospective cohort study of consecutive patients undergoing total thyroidectomy by capsular dissection technique over a 3-year period. Exclusion criteria included performance of concomitant central neck dissection, hyperparathyroidism, revision surgery, and invasive cancer.

METHODS

The number of parathyroid glands identified intraoperatively was recorded. No effort was made to find glands that were not obviously apparent during the course of dissection. Patients were not placed on routine calcium supplementation.

RESULTS

The final study population consisted of 126 patients. The mean number of parathyroid glands identified was 2.3. The incidence of biochemical (any postoperative calcium <2 mmol/L) and clinical hypocalcemia was 22.2% and 10.3%, respectively. Patients in group A (0-2 parathyroids identified) had a significantly lower incidence of clinical hypocalcemia than patients in group B (3-4 parathyroids identified) (3.2% vs. 17.1%, P = .02). The differences in biochemical hypocalcemia were not significant (16.1% vs. 28.1%, P = .13). The incidence of inadvertent parathyroidectomy was 9.5%. There was no difference between the groups in incidence of inadvertent parathyroidectomy (9.7% vs. 9.4%, P = 1.0).

CONCLUSIONS

Routine identification of all four parathyroid glands is not necessary in thyroidectomy performed using capsular dissection technique.

Central lymph node dissection in patients with papillary thyroid cancer: a population level analysis of 14,257 cases

BACKGROUND

This study analyzes the impact of demographics and tumor size on the use of central compartment lymph node dissection (CLND) for papillary thyroid cancer (PTC) in the United States.

METHODS

Adult patients with PTC and the follicular variant of PTC who underwent thyroidectomy with or without CLND and were reported in the Surveillance Epidemiology and End Results (SEER) database from 2004 to 2008 were included. Bivariate and multivariate analyses were performed to determine the effects of demographic and clinical characteristics on the likelihood of a patient undergoing CLND.

RESULTS

Of 14,257 patients included, 80.3% were women, 84.3% were white, average age was 50.1 years, and 37.1% had CLND. Over 5 years, there was an 18.3% increase in CLND, with the greatest increase seen in patients with T1 tumors (23.2%). Patients who were older, men, black, and from the South were less likely to undergo CLND; however, there were no differences in the total number of lymph nodes examined based on patient demographics or the year of their thyroid cancer diagnoses.

CONCLUSIONS

Being older, black, and from the South are negatively associated with CLND. This practice variation suggests potential disparity in access and quality of surgical care for PTC in the United States.

BRAFV600E status and clinical characteristics in solitary and multiple papillary thyroid carcinoma: experience of 512 cases at a clinical center in China

Background

Papillary thyroid carcinoma (PTC) is one of the most frequent endocrine malignancies. In most cases, it often presents as multifocal tumor. It has been reported that multifocal tumors are associated with elevated risk of lymph node and distant metastases. Multifocality is also one of the factors predicting prognosis. Recent studies show that BRAF^V600E mutation occurs more frequently in aggressive PTC. The purpose of this study was to evaluate BRAF^V600E status and clinicopathological features in multiple and solitary PTC.

Methods

We performed a retrospective study to analyze 512 PTC cases who received surgery, including 376 solitary PTCs and 136 multiple PTCs.

Results

Multiple PTC is more related to lymph node metastasis and vascular invasion than solitary PTC. However, the distant metastasis rate and 10-year survival rate showed no difference between these two groups. BRAF^V600E mutation status was more frequent in multiple PTC patients with lymph node metastasis and late stage at diagnosis.

Conclusion

BRAF^V600E mutation is most commonly associated with extra-thyroidal extension and lymph node metastasis in PTC. Multiple PTC patients with young age, large tumors and BRAF^V600E mutation should be followed carefully. Our study provides useful information for PTC patients’ followup and treatment.

Prognostic impact of tumour multifocality in thyroid papillary microcarcinoma based on a series of 160 cases

OBJECTIVE

The objective of this study was to evaluate the prognostic impact of tumour multifocality in papillary thyroid microcarcinoma (PTMC).

METHODS

All patients who underwent total thyroidectomy and central neck dissection for PTMC in our institution between 1990 and 2007 were included in this retrospective study. Statistical correlations between tumour multifocality and various clinical or pathological prognostic parameters were assessed by univariate and multivariate analyses.

RESULTS

A total of 160 patients (133 women and 27 men; mean age: 47.8±13.7 years) were included in this study. Tumour multifocality was demonstrated in 59 (37%) patients. Central neck metastatic lymph node involvement was identified in 46 (28%) patients. No statistical correlation was demonstrated between tumour multifocality and the following factors: age, gender, tumour size, extension beyond the thyroid, metastatic central neck lymph node involvement and risk of recurrence. A tumour diameter greater than 5mm was associated with a higher risk of recurrence (P=0.008).

CONCLUSION

Tumour multifocality does not appear to have a prognostic impact in PTMC.

Advances in surgical therapy for thyroid cancer

Thyroid cancer is the most common malignancy of the endocrine system and its incidence has dramatically increased over the past three decades. Well-differentiated thyroid cancers (DTCs) are the main focus of this article, as they represent >90% of thyroid malignancies. This Review provides an overview of the controversies surrounding the optimal choice of surgery and extent of resection for patients with low-risk DTC or with papillary thyroid microcarcinoma, and the role of prophylactic central lymph node dissection. This Review also outlines the current surgical management of DTC and presents updated results for these techniques, along with important advances and current dilemmas in surgical approaches to treatment of these cancers. For example, endoscopic and robotic thyroidectomy are the two most recent innovations to present technical and other challenges to the endocrine surgeon; in addition, the risks as well as the advantages of same-day thyroid surgery, which has gained some acceptance, are detailed. Arguments for and against each approach are presented, along with supporting evidence. The authors' personal opinions are also provided for each topic.