Subclinical Central Lymph Node Metastasis Research Articles

Chronic lymphocytic thyroiditis protects against recurrence in patients with cN0 papillary thyroid cancer

BackgroundChronic lymphocytic thyroiditis (CLT) frequently coexists with papillary thyroid carcinoma (PTC) that exhibits normal thyroid function. However, few studies have investigated the relationship between CLT and clinically lymph node (LN)-negative PTC. The aim of this study was to evaluate the relationship between subclinical central LN metastasis and CLT, and to assess the impact of CLT on the recurrence of clinically LN-negative PTC. MethodsWe investigated the medical records of 850 patients with PTC who underwent prophylactic bilateral central neck dissection as well as total thyroidectomy between 2004 and 2010; the median follow-up time was 95.5 months (range, 12–158 months). ResultsCLT was observed in 480 patients (56.5%). Female sex, a preoperative thyroid-stimulating hormone level >2.5 mU/L, a primary tumor ≤1 cm, no gross extrathyroidal extension, high number of harvested LNs, low number of metastatic LNs, and positive anti-thyroglobulin (Tg) antibody at 1 year post-initial treatment were significantly associated with the presence of CLT. Multivariate analysis revealed that patients with N1a stage (vs. N0 stage; hazard ratio [HR], 3.255; 95% confidence interval [CI], 1.290–8.213; p = 0.012) and positive anti-Tg antibody at 1 year post-initial treatment (vs. negative anti-Tg antibody; HR, 5.118; 95% CI, 2.130–12.296; p < 0.001) had poorer recurrence-free survival (RFS), while those with CLT (vs. no CLT; HR, 0.357; 95% CI, 0.157–0.812; p = 0.014) had favorable RFS outcomes. ConclusionsCLT is associated with less aggressive tumor characteristics and LN metastasis. Clinically LN-negative PTC patients with CLT experience longer RFS intervals than those without CLT.

Comparative Study between Robotic Total Thyroidectomy with Central Lymph Node Dissection via Bilateral Axillo-breast Approach and Conventional Open Procedure for Papillary Thyroid Microcarcinoma.

Background:A large proportion of the patients with papillary thyroid microcarcinoma are young women. Therefore, minimally invasive endoscopic thyroidectomy with central neck dissection (CND) emerged and showed well-accepted results with improved cosmetic outcome, accelerated healing, and comforting the patients. This study aimed to evaluate the safety and effectiveness of robotic total thyroidectomy with CND via bilateral axillo-breast approach (BABA), compared with conventional open procedure in papillary thyroid microcarcinoma.Methods:One-hundred patients with papillary thyroid microcarcinoma from March 2014 to January 2015 in Jinan Military General Hospital of People's Liberation Army (PLA) were randomly assigned to robotic group or conventional open approach group (n = 50 in each group). The total operative time, estimated intraoperative blood loss, numbers of lymph node removed, visual analog scale (VAS), postoperative hospital stay time, complications, and numerical scoring system (NSS, used to assess cosmetic effect) were analyzed.Results:The robotic total thyroidectomy with CND via BABA was successfully performed in robotic group. There were no conversion from the robotic surgeries to open or endoscopic surgery. The subclinical central lymph node metastasis rate was 35%. The mean operative time of the robotic group was longer than that of the conventional open approach group (118.8 ± 16.5 min vs. 90.7 ± 10.3 min, P < 0.05). The study showed significant differences between the two groups in terms of the VASs (2.1 ± 1.0 vs. 3.8 ± 1.2, P < 0.05) and NSS (8.9 ± 0.8 vs. 4.8 ± 1.7, P < 0.05). The differences between the two groups in the estimated intraoperative blood loss, postoperative hospital stay time, numbers of lymph node removed, postoperative thyroglobulin levels, and complications were not statistically significant (all P > 0.05). Neither iatrogenic implantation nor metastasis occurred in punctured porous channel or chest wall in both groups. Postoperative cosmetic results were very satisfactory in the robotic group.Conclusions:Robotic total thyroidectomy with CND via BABA is safe and effective for Chinese patients with papillary thyroid microcarcinoma who worry about the neck scars.

Impact of tumor size on subclinical central lymph node metastasis in papillary thyroid microcarcinoma depends on age.

BackgroundThe aim of this study is to evaluate whether the associations between clinicopathologic factors of papillary thyroid microcarcinoma (PTMC), especially tumor size, and subclinical central lymph node metastasis (LNM) are dependent on patient age.MethodsThe medical records of 428 patients who underwent thyroid surgery for PTC measuring ≤1 cm were reviewed. All patients were clinically lymph node negative and underwent thyroidectomy with unilateral or bilateral central lymph node dissection. Univariate and multivariate analyses were performed to identify clinicopathologic factors associated with central LNM.ResultsCentral LNM was identified in 96 of 428 (22.4%) patients. Mean tumor size was significantly greater in patients with than without central LNM (0.74 ± 0.22 cm vs. 0.64 ± 0.23 cm, P = 0.001). Tumor size > 0.5 cm was significantly predictive of central LNM. Subgroup analysis according to age groups showed that tumor size was an independent predictor of subclinical central LNM only in patients aged ≥45 years.ConclusionsFactors predictive of central LNM in patients with PTMC differed by age. PTMC size was an independent predictor of subclinical central LNM only in patients aged ≥45 years.

Upregulation of HGF and c-MET is Associated with Subclinical Central Lymph Node Metastasis in Papillary Thyroid Microcarcinoma

Identification of a novel biomarker of subclinical lymph node metastasis (SLNM) in papillary thyroid microcarcinoma (PTMC) could provide important clues regarding SLNM in PTMC. We evaluated the significance of HGF and c-Met expression in surgically removed tumor tissue from PTMC patients as a predictive marker of SLNM. We analyzed the immunohistochemical relationship between HGF and c-Met expression and SLNM in 113 surgically treated PTMC patients with clinically negative nodes presurgery. In addition, we explored whether HGF/c-Met pathway activation enhanced the in vitro migration and invasion of PTC cells. Positive immunohistochemical HGF and c-Met staining was found in 107 (95 %) and 103 (91 %) cases, respectively. The HGF staining distribution was as follows: no staining in 6 cases, weak staining in 43, moderate staining in 55, and strong staining in 9. Of the nine cases with strong HGF staining, eight (89 %) had SLNM. The c-Met staining distribution was as follows: no staining in 10 cases, weak staining in 39, moderate staining in 59, and strong staining in 5. Of the five cases with strong c-Met staining, three (60 %) had SLNM. The presence of SLNM was strongly correlated with HGF and c-Met expression in PTMC in a univariate analysis (P < 0.05). HGF overexpression was also associated with SLNM in a multivariate analysis (P < 0.05). Stimulation with exogenous HGF and constitutive activation of c-Met enhanced the migration and invasion of PTC cells in vitro by enhancing VEGF-A expression. HGF/c-Met pathway activation is associated with SLNM of the central neck in PTMC.

Subclinical Central Lymph Node Metastasis in Papillary Thyroid Microcarcinoma Evaluated as cT1aN0 by Preoperative Imaging Study

Subclinical Central Lymph Node Metastasis in Papillary Thyroid Microcarcinoma Evaluated as cT1aN0 by Preoperative Imaging Study

Impact of Clinicopathologic Factors on Subclinical Central Lymph Node Metastasis in Papillary Thyroid Microcarcinoma

PurposeWe evaluated whether the clinicopathological factors of papillary thyroid microcarcinoma (PTMC), especially tumoe size, are associated with subcinical central lymph node metastasis.Materials and MethodsA total of 160 patients diagnosed with PTMC who underwent total thyroidectomy with bilateral central lymph node dissection were enrolled in this study. All patients were clinically lymph node negative PTMC. Patients were divided into 2 groups according to the size of tumor (≤5 mm vs. >5 mm). Clinicopathologic risk factors for subclinical central lymph node metastasis were analyzed.ResultsSubclinical central lymph node metastasis was detected in 61 (38.1%). Patients with tumors ≤5 mm had a lower frequency of extrathyroidal extension, multifocality and subclinical central lymph node metastasis. On multivariate analysis, only male and tumor size >5 mm were independent predictors of subclinical central lymph node metastasis; age, multifocality, bilaterality, extrathyroidal extension, lymphvascular invasion and lymphocytic thyroiditis were not.ConclusionIn this study, male and tumor size >5 mm were two independent predictive factors for subclinical central lymph node metastasis in PTMC. These are easier factors to assess before surgery than other factors when planning the central lymph node dissection. However, further long-term follow-up studies are needed to confirm the prognostic significance of subclinical central lymph node metastasis in PTMC.

Prophylactic central lymph node dissection for clinically node-negative papillary thyroid microcarcinoma: Influence on serum thyroglobulin level, recurrence rate, and postoperative complications

In papillary thyroid microcarcinoma (PTMC), regional lymph node metastasis (LNM) is associated with a increased locoregional recurrence rate. Yet, prophylactic central lymph node dissection (CLND) targeting subclinical central LNM continues to be a matter of debate in the treatment of PTMC, which generally carries an excellent prognosis. The aim of our study was to investigate the benefits and risks of prophylactic CLND in patients with clinically node-negative PTMC. This study included 232 patients who underwent surgery for clinically node-negative PTMC from 1999 to 2006. Of these 232 patients, 113 underwent only total thyroidectomy (TT) and 119 underwent TT in conjunction with prophylactic bilateral CLND (TT with CLND). We then compared serum thyroglobulin (Tg) levels, recurrence rates, and postoperative complications between the 2 groups (TT only and TT with CLND). The postoperative stimulated serum Tg level was significantly less in the TT with CLND group than in the TT only group (1.07 vs. 2.24 ng/mL, respectively; P = .022). The stimulated Tg levels in the 2 groups became similar, however, after low-dose radioactive iodine treatment (0.44 ng/mL vs. 0.69 ng/mL, respectively; P = 0.341). There was no significant difference in 3-year locoregional control rates after TT with CLND and TT only (98.3% vs. 96.5%, respectively; P = .368). Although the frequency of permanent hypocalcemia was approximately 3 times greater in the TT with CLND group (5.6%) than in the TT only group (1.8%), this finding did not reach statistical significance. With prophylactic CLND, the postoperative Tg level can significantly decrease. However, prophylactic CLND is not helpful in decreasing short-term locoregional recurrence in patients with clinically node-negative PTMC. Finally, the risk of permanent hypocalcemia may increase after CLND.

Subclinical lymph node metastasis in papillary thyroid microcarcinoma: A study of 551 resections

In clinically node-negative papillary thyroid microcarcinoma (PTMC), the frequency of subclinical lymph node metastasis (LNM) in the central cervical compartment (subclinical central LNM) has been reported to be as great as 65%. Routine prophylactic central compartment lymph node dissection (CLND) has been debated, because the risk of operative complications might outweigh its prognostic benefit. We aimed to study clinicopathologic factors associated with subclinical central LNM to be considered for determination of prophylactic CLND. A total of 551 patients diagnosed with clinically node-negative PTMC from 2005 to 2009 were included. All patients underwent total thyroidectomy (TT) and prophylactic CLND. Clinicopathologic risk factors of subclinical central LNM were analyzed. In addition, we investigated recurrences and postoperative complications after TT and CLND. Among the 551 patients, 202 (37%) had subclinical central LNM. On univariate and multivariate analyses, male gender, tumor multifocality, and extrathyroidal extension were independently predictive of subclinical central LNM. During 3-year follow-up, there were no recurrences in the central cervical compartment. The frequency of permanent hypocalcemia and permanent vocal fold palsy were 1.1% and 1.3%, respectively. Frequency of subclinical central LNM was high in PTMC. It was managed effectively with prophylactic CLND. In addition, prophylactic CLND did not cause significant permanent morbidities. We recommend that clinicopathologic features, such as male gender, tumor multifocality, and extrathyroidal extension, be considered for determination of prophylactic CLND in patients with PTMC.