Excellent Prognosis of Central Lymph Node Recurrence-Free Survival for cN0M0 Papillary Thyroid Carcinoma Patients Who Underwent Routine Prophylactic Central Node Dissection

Predictors of response to Radioactive Iodine Therapy in Intermediate and high risk patients with papillary thyroid carcinoma

BACKGROUND

Radioactive iodine (RAI) therapy is the standard treatment approach after total thyroidectomy in patients with papillary thyroid carcinoma (PTC). We aimed to identify predictive factors of response to the treatment in intermediate and high-risk patients with PTC. In addition, the impact of multiple RAI treatments was explored.

METHODS

In a 3-year retrospective study, data from intermediate and high-risk patients with PTC who received RAI therapy following total thyroidectomy, were analyzed by the end of year-one and year-three. Demographic data, tumor size, capsular/vascular invasion, extrathyroidal extension, local or distant metastasis, initial dose and cumulative dose of RAI, serum thyroglobulin(Tg), antithyroglobulin antibody(TgAb), and imaging findings were investigated. Patients with an excellent response to a single dose of RAI treatment, after three years of follow-up were classified as the "Responder group". Excellent response was defined as stimulated serum Tg less than 1 ng/ml, or unstimulated serum Tg less than 0.2 ng/ml in TgAb-negative patients with negative imaging scans.

RESULTS

333 patient records with a complete data set were analyzed in this study. After three years of initial treatment, 271 patients were non-responders (NR) and 62 were responders (R). At baseline, the median pre-ablation serum Tg level was 5.7 ng/ml in the NR group, and 1.25 ng/ml in the R group (P < 0.001). TSH-Stimulated serum Tg greater than 15.7 ng/ml, was associated with response failure even after multiple RAI therapy, AUC: 0.717(0.660-0.774), sensitivity: 52.5%, specificity: 89.47%, P < 0.001. On the other hand, multiple RAI therapy was associated with excellent response in 16.2% of the patients. The chance of ER was decreased by 74% if initial post-operation ultrasound imaging confirmed the presence of locoregional involvement, OR 0.26, (95% CI: 0.12-0.55), P < 0.001.

CONCLUSION

Stimulated serum Tg and locoregional involvement after total thyroidectomy are predictive factors of non-response to RAI therapy in intermediate and high-risk patients with PTC. In addition, a minority of patients achieve excellent response after multiple RAI therapy.

Impact of prophylactic central lymph node dissection on the complications and recurrence rates in papillary thyroid carcinoma-An AFCE (French-speaking Association of Endocrine Surgery) multicentre study based on the EUROCRINE® national data

BACKGROUND

Prophylactic central neck dissection (pCND) remains controversial during the initial surgery for preoperative and intraoperative node-negative (cN0) papillary thyroid carcinoma (PTC).

METHODS

Patients undergoing thyroidectomy with or without pCND (Nx) for PTC in nine French surgical departments, registered in the EUROCRINE® national data in France between January 2015 and June 2021, were included in a cohort study. Demographic and clinicopathological characteristics, complications, and recurrence rates were compared using multivariate regression analysis.

RESULTS

A total of 1905 patients with cN0 PTC were enrolled, including 1534 who had undergone pCND and 371 who hadn't (Nx). Of these, 1546 (81.2%) were female, and the median age was 49 years (range: 15-89 years). Patients who had undergone pCND were more likely to have multifocal tumors (n = 524 [34.2%] vs. n = 68 [18.3%], p < .001) and larger tumors (15.3 vs. 10.2 mm, p = .01) than patients with Nx. Of the patients with pCND, 553 (36%) had positive central LN (N1a), with a median of 1 N1 (IQR 0-5). pCND was associated with a higher temporary hypocalcemia rate (n = 25 [8%] vs. n = 15 [4%], p < .001). The rates of permanent hypocalcemia and temporary and permanent recurrent laryngeal nerve (RLN) palsy were not significantly different between the two groups (p > .2). After adjusting for covariates (age, sex, multifocality, and pathological T stage) in a multivariable Cox PH model, the performance of lymph node dissection (pCND vs. no-pCND) was not associated with PTC recurrence (p = .2).

CONCLUSION

pCND in PTC does not reduce recurrence and is associated with a two-fold increase in the incidence of transient hypoparathyroidism. These data should be considered while issuing further guidelines regarding the treatment of patients with cN0 PTC.

Intraoperative pathologic evaluation of central compartment lymph nodes in patients undergoing lobectomy for unilateral papillary thyroid carcinoma

BACKGROUND/OBJECTIVE

Although papillary thyroid carcinoma (PTC) has an excellent prognosis, it can cause central lymph node metastasis (CLNM) which can increase local recurrence. Intraoperative pathologic evaluation (IOPE) can provide evidence regarding CLNM and help surgeons determine the appropriate surgical approach. The aim of this study was to evaluate the efficacy of IOPE and to determine risk factors associated with CLNM in unilateral PTC without preoperative clinical evidence of CLNM.

METHODS

Medical charts of 227 patients who had unilateral PTC without clinical lymph node metastasis preoperatively were reviewed retrospectively. They were scheduled for thyroid lobectomy and prophylactic central lymphadenectomy (CND) from January 1, 2017 to December 31, 2017.

RESULTS

Total follow-up period was 47.6 ± 10.6 months. CLNM was identified in 57 (25.1%) patients during IOPE and in 72 (31.7%) patients during final pathological analysis. The sensitivity and specificity of IOPE were 76.4% and 98.7%, respectively. IOPE through central lymph node dissection was safely performed with low complications (vocal cord palsy, 5.7%; hypoparathyroidism, 22.8%). Age < 55 years, echogenic foci on preoperative ultrasonography, and extrathyroidal extension at final pathological report were significantly associated with an increased risk of CLNM (p = 0.006, p < 0.001, and p < 0.001, respectively). In terms of oncological outcomes, there was no significant difference between the true negative and false negative results in IOPE.

CONCLUSION

IOPE can safely provide accurate information for determining disease status and surgical extent. Further long-term studies are needed to evaluate clinical benefits of IOPE.

Risk factors associated with high-risk nodal disease in patients considered for active surveillance of papillary thyroid microcarcinoma without extrathyroidal extension

Background

Active surveillance (AS) has become an alternative treatment approach for papillary thyroid microcarcinoma (PTMC). The purpose of this study is to uncover the clinicopathological factors associated with high-risk nodal disease in order to select proper candidates for AS of PTMC.

Methods

We retrospectively reviewed 5,329 patients with PTMC without extrathyroidal extension (ETE) who underwent thyroidectomy with central compartment neck dissection (CCND) between 2007 and 2021 at Seoul St. Mary's Hospital. Patients with more than five metastatic lymph nodes (MLNs) (higher-risk N1 disease) and/or lateral neck node metastases (N1b disease) were defined as having high-risk nodal disease. The clinicopathological factors associated with high-risk nodal disease were analyzed.

Results

A total of 415 (7.8%) patients had higher-risk N1 disease. These patients were younger on average, included a higher proportion of males, and had a larger tumor size and more frequent capsular invasion and multifocality compared with other patients. For the tumor size, a cutoff value of 0.65 cm was the best predictor of nodal risk groups. In a multivariate analysis, the independent risk factors associated with higher-risk N1 disease were younger age, male sex, tumor size >0.65 cm, and the presence of capsular invasion and/or multifocality. A total of 246 (4.6%) patients had N1b disease at initial diagnosis. In a multivariate analysis, the independent risk factors associated with N1b disease were younger age, male sex, tumor size >0.65 cm, and the presence of capsular invasion and/or multifocality.

Conclusions

Young age, male sex, tumor size >0.65 cm, and presence of capsular invasion and/or multifocality can be considered risk factors for high-risk nodal disease in PTMC. Therefore, cautious observation is necessary for AS of patients with these characteristics.

Clinical efficacy of gasless submental-transoral endoscopic thyroidectomy with Kirschner wire suspension for papillary thyroid carcinoma

PURPOSE

To analyze the clinical efficacy of gasless submental-transoral endoscopic thyroidectomy (ETE) with Kirschner wire suspension in patients with papillary thyroid carcinoma (PTC).

METHODS

Retrospectively, we enrolled 112 patients with PTC who received treatment in The Second Affiliated Hospital of Nanchang University between December 2020 and December 2021. Among them, 60 cases (laparoscopic group) received gasless submental-transoral ETE with Kirschner wire suspension, and the other 52 cases (open group) were treated by traditional thyroidectomy. Surgical indicators (operative time (OT), intraoperative blood loss (IBL), and postoperative drainage volume (DV)), number of central lymph node (CLN) dissected, length of hospital stay (LOS), Visual Analogue Scale (VAS) score, aesthetic satisfaction score, and complications were observed and compared between the two groups.

RESULTS

There was no significant difference between the two groups in OT (55.73±5.49 min vs. 55.00±7.79 min), IBL (20.67±7.75 mL vs. 23.08±6.24 mL), postoperative DV (33.17±15.09 mL vs. 39.52±19.22 mL), number of CLN dissected (5.54±2.75 vs. 5.43±3.15), LOS (3.63±0.69 d vs. 3.68±0.57 d), postoperative VAS score (3.19±1.07 points vs. 3.38±1.09 points), and total complication rate (3.85% vs. 8.33%; all P>0.05). However, the laparoscopic group exhibited a significantly higher aesthetic satisfaction score than the open group (7.10±1.46 points vs. 6.42±1.46 points; P<0.05). In addition, patients in both groups were followed up for at least 3 months, and no recurrence or metastasis was observed.

CONCLUSIONS

Gasless submental-transoral ETE with Kirschner wire suspension offers comparable curative effect as traditional thyroidectomy and safety, but it provides superior esthetic results, making it a viable treatment option for patients with PTC.

Guideline for the Surgical Management of Locally Invasive Differentiated Thyroid Cancer From the Korean Society of Head and Neck Surgery

The aim of this study was to develop evidence-based recommendations for determining the surgical extent in patients with locally invasive differentiated thyroid cancer (DTC). Locally invasive DTC with gross extrathyroidal extension invading surrounding anatomical structures may lead to several functional deficits and poor oncological outcomes. At present, the optimal extent of surgery in locally invasive DTC remains a matter of debate, and there are no adequate guidelines. On October 8, 2021, four experts searched the PubMed, Embase, and Cochrane Library databases; the identified papers were reviewed by 39 experts in thyroid and head and neck surgery. The Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach was used to assess the quality of evidence, and to develop and report recommendations. The strength of a recommendation reflects the confidence of a guideline panel that the desirable effects of an intervention outweigh any undesirable effects, across all patients for whom the recommendation is applicable. After completing the draft guidelines, Delphi questionnaires were completed by members of the Korean Society of Head and Neck Surgery. Twenty-seven evidence-based recommendations were made for several factors, including the preoperative workup; surgical extent of thyroidectomy; surgery for cancer invading the strap muscles, recurrent laryngeal nerve, laryngeal framework, trachea, or esophagus; and surgery for patients with central and lateral cervical lymph node involvement. Evidence-based guidelines were devised to help clinicians make safer and more efficient clinical decisions for the optimal surgical treatment of patients with locally invasive DTC.

Predictive value of metastatic lateral lymph node ratio for recurrence in pathologically lateral lymph node-positive papillary thyroid cancer patients with palpable lymph nodes

BACKGROUND

This study aimed to identify the predictive value of the extent of metastatic lymph nodes in the central and lateral neck compartment for recurrence in papillary thyroid cancer (PTC) patients with pathologically lateral lymph node metastasis (pN1b).

METHODS

This study enrolled 252 patients with pN1b from PTC.

RESULTS

During a mean follow-up of 17.6 years, 55 (21.8%) patients experienced recurrence. Patients with palpable lymph nodes were more likely to have a recurrence than those with nonpalpable lymph nodes (30.1% vs. 17.8%, relative risk 1.7, 95%CI: 1.1-2.7). For patients with palpable metastatic lymph nodes, lymph node ratio of lateral lymph nodes ≥0.5 (aHR = 2.906, 95%CI: 1.29-6.54) and age ≥55 years (aHR = 2.508, 95%CI: 1.12-5.63) were independent prognostic factors. For those without palpable nodes, age ≥55 years (aHR = 2.224, 95%CI: 1.08-4.60) and tumor size >4 cm (aHR = 2.168, 95%CI: 1.01-4.66) were independently predictive of worse RFS.

CONCLUSIONS

Palpable lymph nodes were approximately twice as likely to recur as nonpalpable nodes. Metastatic lateral lymph node ratio predicts recurrence in pN1b PTC patients with palpable lymph nodes, but not those without ones.

A Narrative Review of Preventive Central Lymph Node Dissection in Patients With Papillary Thyroid Cancer - A Necessity or an Excess

Objective

This review article summarises the latest evidence for preventive central lymph node dissection in patients with papillary thyroid cancer taking into account the possible complications and risk of recurrence.

Background

Papillary thyroid cancer is the most frequent histological variant of malignant neoplasms of the thyroid gland. It accounts for about 80-85% of all cases of thyroid cancer. Despite good postoperative results and an excellent survival rate in comparison with many other malignant diseases, tumor metastases to the cervical lymph nodes are frequent. Most researchers agree that the presence of obvious metastases in the lymph nodes requires careful lymph node dissection. It was suggested to perform preventive routine lymphadenectomy in all patients with malignant thyroid diseases referred to surgery.

Methods

It was performed the literature review using the “papillary thyroid cancer”, “central lymph node dissection”, “hypocalcemia”, “recurrent laryngeal nerve paresis”, “metastasis”, “cancer recurrence” along with the MESH terms. The reference list of the articles was carefully reviewed as a potential source of information. The search was based on Medline, Scopus, Google Scholar, eLibrary engines. Selected publications were analyzed and their synthesis was used to write the review and analyse the role of preventive central lymph node dissection in patients with papillary thyroid cancer.

Conclusions

The necessity of preventive central lymph node dissection in patients with differentiated papillary thyroid carcinoma is still controversial. There is much evidence that it increases the frequency of transient hypocalcemia. Due to the fact that this complication is temporary, its significance in clinical practice is debatable. It can also be assumed that an extant of surgery in the neck area is associated with an increased risk of recurrent laryngeal nerve injury. However, most studies indicate that this injury is associated more with thyroidectomy itself than with lymph node dissection. Recurrent laryngeal nerve dysfunction is also a temporary complication in the vast majority of cases. At the same time, a large amount of data shows that central lymph node dissection reduces the risk of thyroid cancer recurrence in two times.

Prophylactic bilateral central neck dissection should be evaluated based on prospective randomized study of 581 PTC patients

BACKGROUND

Prophylactic central lymph node dissection (PCND) was a basic consensus for patients with papillary thyroid carcinoma (PTC) in China. However, unilateral or bilateral central lymph node dissection (CND) was still controversial. This study aimed at investigating the safety and long-term benefit for the patients undergone with bilateral central lymph node dissection (BCCD).

METHODS

581 patients were enrolled and divided randomly into the test and control groups according to range of CND. 285 patients were prospectively assigned to undergo thyroid lobectomy plus BCND in the test group, other 296 patients were assigned to undergo thyroid lobectomy plus ipsilateral central lymph node dissection (ICND) in the control group.

RESULTS

We found that the numbers of total LN and pN1a in the test group were more than that of the control group (p = 0.002,0.004), but there was no difference in the number of metastasized lymph nodes (p = 0.857) and tumor recurrence (p = 0.308). Additionally, in the aspect of postoperative complication (1 day after surgery), the serum levels of parathyroid hormone in the BCND group were lower than that in the ICND group (P = 0.010), and the numbers of transient laryngeal nerve palsy were more than that(p = 0.033). Meanwhile, we further found that pathological tumor size larger than 1 cm and tumor side lymph node metastasis were independent risk factors for contralateral central lymph node metastasis(p = 0.002,0.001).

CONCLUSION

BCND may be an alternative for patients with tumor sizes larger than 1 cm, but it would significantly increase the rate of transient vocal cord palsy, parathyroid auto transplantation and decreased PTH, but the risk of permanent complications was similar to the ICND group.

Fine-Needle Pricking Test of the Parathyroid Gland during Thyroid Surgery in Predicting Parathyroid Function

BACKGROUND

Permanent hypoparathyroidism is a serious complication following total thyroidectomy plus central neck dissection (CND). How to evaluate the vascularization of the parathyroid gland in real time is a major concern of thyroid surgeons. This study aimed to evaluate the fine-needle pricking (FNP) test in predicting parathyroid gland function.

METHODS

The FNP test was performed in patients undergoing total thyroidectomy plus CND between January 1, 2014, and December 31, 2019, to visualize the vascularization of the parathyroid glands. Patients were classified according to the number of parathyroid glands preserved in situ with excellent vascularity (PGPIEV) demonstrated by FNP: group 0 (without PGPIEV), group 1 (with one PGPIEV), group 2 (with two PGPIEV), group 3 (with three PGPIEV), and group 4 (with four PGPIEV).

RESULTS

A total of 608 patients with four parathyroid glands underwent FNP testing during thyroidectomy. At least one PGPIEV was demonstrated by FNP testing in 581 patients who had intact parathyroid hormone (iPTH) levels in the normal range after the operation. The prevalence of hypocalcemia decreased from 77.8% in group 0 to 9.8% in group 4 (P < 0.001), and the incidence of hypoparathyroidism decreased from 44.4% in group 0 to 0% in groups 1-4 (P < 0.001). iPTH concentrations on postoperative day 1 were positively correlated with PGPIEV groups (increased from 14.58 ng/l in group 0 to 45.22 ng/l in group 4, P < 0.001).

CONCLUSIONS

The FNP test is a safe and reliable method to predict parathyroid function. One PGPIEV demonstrated by the FNP test rules out the possibility of patients developing hypoparathyroidism.

Carbon nanoparticle-guided intraoperative lymph node biopsy predicts the status of lymph nodes posterior to right recurrent laryngeal nerve in cN0 papillary thyroid carcinoma

BACKGROUND

The lymph nodes in the right central compartment can be divided into 2 parts by the right recurrent laryngeal nerve (RLN), and there is a lack of an accurate and convenient method for assessing metastases in the lymph node posterior to the right recurrent laryngeal nerve (LN-prRLN) in cN0 thyroid papillary carcinoma patients.

METHODS

Patients diagnosed with cN0 thyroid papillary carcinoma and underwent intraoperative carbon nanoparticle-guided lymph node biopsy from January 2017 to November 2020 at the Center for Thyroid and Breast Surgery of Xuanwu Hospital were retrospectively analyzed. The intraoperative frozen section examination and postoperative LN-prRLN status should have been comprehensively recorded. The participants were divided into the LN-prRLN positive group and LN-prRLN negative group according to their recorded LN-prRLN status.

RESULTS

In total, 189 cases (LN-prRLN positive group, n=30; LN-prRLN negative group, n=159) were included in the analysis. The univariate and multivariate regression analyses revealed that the number of metastatic lymph nodes during intraoperative lymph node biopsy was the potential predictor for LN-prRLN metastasis [odds ratio (OR): 1.320, 95% confidence interval (CI): 1.057 to 1.649, P=0.014]. The receiver operating characteristic (ROC) curve showed that the area under the curve (AUC) reached 0.7 upon a combined analysis of multiple lymph node statuses located at pre-laryngeal (Delphian), pre-tracheal, and para-tracheal lymph nodes ipsilateral to the tumor in predicting the metastasis of LN-prRLN, and the cut-off value was 0.5.

CONCLUSIONS

Number of metastatic lymph nodes in intraoperative biopsy was an indicator of LN-prRLN metastasis in cN0 thyroid carcinoma patients. Patients staging in cN0 with negative intraoperative lymph node status might be considered not to require LN-prRLN dissection during central lymph nodes dissection.

Clinicopathological Features as Prognostic Predictors of Poor Outcome in Papillary Thyroid Carcinoma

Simple Summary

Thyroid cancer incidence is increasing, with overdiagnosis being the major driver of the thyroid cancer “epidemic”. Papillary thyroid carcinoma, usually with excellent prognosis, sometimes has an aggressive metastatic pattern. This heterogeneity in progression makes it difficult to tailor treatment strategies for an individual patient. We aimed to identify clinicopathological factors associated with papillary thyroid carcinoma recurrence, persistence, and specific mortality. Our study supports that both pre-surgical factors, such as male gender, presence of psammoma bodies, gross extra-thyroidal extension, and lateral compartment lymph node metastases, as well as lymph vessel invasion, venous invasion, presence of necrosis, and incomplete surgical resection, should be taken into consideration regarding treatment and follow-up of PTC patients. The same is true when analysis is restricted to stage I patients. The importance of this report is to emphasize clinical and imaging pre-surgical thyroid cancer patients’ evaluation for an appropriate surgical treatment and patient prognosis.

Abstract

Papillary thyroid cancer (PTC) has an indolent nature and usually excellent prognosis. Some PTC clinicopathological features may contribute to the development of aggressive metastatic disease. In this work, we want to evaluate PTC clinicopathological features that are presurgical prognostic predictors of patients’ outcomes and find which indicators are more adequate for tailoring surgical procedures and follow-up. We studied a series of 241 PTC patients submitted to surgery. All patients’ files and histological tumor samples were reviewed. The 8th edition AJCC/UICC (American Joint Committee on Cancer/Union for International Cancer) Controlstaging system and the 2015 American Thyroid Association risk stratification system were used. Total thyroidectomy was performed in 228 patients, lymphadenectomy in 28 patients. Gross extrathyroidal extension (ETE) was present in 10 patients and 31 tumor resection margins were incomplete. Cervical lymph node metastases (LNMs) were present in 34 patients and distant metastases at diagnosis in four patients. In multivariate analysis, male gender (OR = 15.4, p = 0.015), venous invasion (OR = 16.7, p = 0.022), and lateral compartment LNM (OR = 26.7, p = 0.004) were predictors of mortality; psammoma bodies (PBs) (OR = 4.5, p = 0.008), lymph vessel invasion (OR = 6.9, p < 0.001), and gross ETE (OR = 16.1, p = 0.001) were predictors of structural disease status; male gender (OR = 2.9, p = 0.011), lymph vessel invasion (OR = 2.8, p = 0.006), and incomplete resection margins (OR = 4.6, p < 0.001) were predictors of recurrent/persistent disease. Our study supports that the factors helping to tailor patient’s surgery are male gender, presence of PBs, gross ETE, and lateral compartment LNM. Together with pathological factors, lymph vessel invasion, venous invasion, necrosis, and incomplete surgical resection, should be taken into consideration regarding treatment and follow-up of patients.

Synergic effects of histology subtype, lymph node metastasis, and distant metastasis on prognosis in differentiated thyroid carcinoma using the SEER database

Background

Differentiated thyroid carcinoma (DTC) is the most common clinical type of thyroid carcinoma. There are rare reports on the synergic effects of the different clinicopathological risk factors on the prognosis of it.

Methods

We retrospectively reviewed data on 86,032 DTC patients from the Surveillance, Epidemiology, and End Results (SEER) database. Univariate and multivariate Cox regression analyses were conducted to evaluate the correlation between clinicopathological factors and the prognosis of DTC. Relative excess risk (RERI) of synergic effect, attributable proportion (AP) of synergic effect, and synergy index (SI) were calculated to assess synergic effects. Kaplan-Meier analyses with log-rank tests was used to plot the survival curve affected by different risk factors.

Results

Histology subtype, lymph node metastasis (LNM) status, and distant metastasis (DM) were independent risk factors for cancer-specific survival (CSS) and all-cause survival (ACS) in the multivariate analysis (all, P<0.001). Patients' age at diagnosis, sex, extrathyroidal extension, and radiation also influenced prognosis (all, P<0.001). The cancer-specific mortality (CSM) and all-cause mortality (ACM) rates per 1,000 person-years were higher in patients with follicular thyroid carcinoma (FTC) and in those with N1 stage and M1 stage disease. Furthermore, we observed a significant synergic effect between histology subtype and N stage, as well as histology subtype and M stage for the CSM of DTC (RERI =48.806, AP =0.853, SI =7.565; RERI =37.889, AP =0.430, SI =1.771, respectively). However, no synergic effect was observed in the case of the N stage and M stage for the CSM of DTC (RERI =7.928, AP =0.084, SI =1.093).

Conclusions

Patients with histology subtype of FTC and N1 stage, histology subtype of FTC and M1 stage had significant additive synergic effects on DTC prognosis for CSM.

Identifying risk factors of recurrence for clinically node negative papillary thyroid carcinoma with pathologic N1a

Background

Whether or not to perform prophylactic central lymph node dissection (CLND) in the case of clinically node-negative papillary thyroid cancer (PTC) is controversial. The purpose of this study was to investigate the risk factors for recurrence in clinically node-negative PTC patients who underwent total thyroidectomy plus bilateral central neck dissection and was verified pathologic N1a.

Methods

We retrospectively reviewed the medical records of 1082 PTC patients who underwent total thyroidectomy and prophylactic bilateral CLND between January 2004 and December 2012. We used Cox-proportional hazard regression analyses in order to explore potential predictive factors for recurrence.

Results

During a median follow-up (range) of 78 (12–158) months, recurrence occurred in 62 (5.7%) patients. Main tumor size more than 1 cm, gross extrathyroidal extension (ETE), positive lymph node (LN) more than 3, and LN ratio > 0.5 were all significantly associated with recurrence according to univariate analysis. In model I multivariate analysis (tumor size, gross ETE, LN ratio), LN ratio > 5 (hazards ratio [HR], 4.794; 95% confidence interval [CI], 2.674–8.595; p < 0.001) was found to be predictive of recurrence. Gross ETE (HR, 1.794; 95% CI, 1.024–3.143; p = 0.041) and positive LN more than 3 (HR, 2.505; 95% CI, 1.513–4.146; p < 0.001) were predictors for recurrence in model II multivariate analysis (tumor size, gross ETE, the number of positive LN).

Conclusions

We recommend that surgeons try to focus completely on performing prophylactic CLND for patients with suspicious gross ETE during preoperative evaluation. Close monitoring and thorough management are needed for clinically node-negative PTC patients with LN ratio of more than 0.5 and more than 3 positive LN in the central compartment.