Preoperative detection and predictors of level V lymph node metastasis in patients with papillary thyroid carcinoma

A combination of computed tomography scan and ultrasound provides optimal detection of cervical lymph node metastasis in papillary thyroid carcinomas: A systematic review and meta-analysis

BACKGROUND

Lymph node metastasis (LNM) in patients with papillary thyroid carcinoma (PTC) is common. This meta-analysis assesses the diagnostic accuracy of computed tomography (CT), ultrasound (US), and CT + US in detecting central and lateral LNM.

METHODS

A systematic review and meta-analysis was performed by searching PubMed, Embase, and Cochrane for studies published up to April 2022. The pooled sensitivity, specificity, and diagnostic odds ratio (DOR) were calculated. The area under the curve (AUC) for summary receiver operating curves (sROC) were compared.

RESULTS

The study population included 7902 patients with a total of 15 014 lymph nodes. Twenty-four studies analyzed the sensitivity of the overall neck region in which dual CT + US imaging (55.9%) had greater sensitivities (p < 0.001) than either US (48.4%) or CT (50.4%) alone. The specificity of US alone (89.0%) was greater (p < 0.001) than CT alone (88.5%) or dual imaging (86.8%). The DOR for dual CT + US imaging was greatest (p < 0.001) at 11.134, while the AUCs of the three imaging modalities were similar (p > 0.05). Twenty-one studies analyzed the sensitivity of the central neck region in which both CT (45.8%) and CT + US imaging (43.4%) had greater sensitivities (p < 0.001) than US alone (35.3%). The specificity of all three modalities was higher than 85%. The DOR for CT (7.985) was greater than US alone (4.723, p < 0.001) or dual CT + US imaging (4.907, p = 0.015). The AUC of both CT + US (0.785) and CT alone (0.785) were significantly greater (p < 0.001) than US alone (0.685). Of the 19 studies that reported lateral LNM, CT + US imaging sensitivity (84.5%) was higher than CT alone (69.2%, p < 0.001) and US alone (79.7%, p = 0.038). The specificity of all imaging techniques was all greater than 80.0%. CT + US imaging DOR (35.573) was greater than CT (20.959, p = 0.024) and US (15.181, p < 0.001) individually. The AUC of independent imaging was high (CT: 0.863, US: 0.858) and improved significantly when combined (CT + US: 0.919, p = 0.024 and p < 0.001, respectively).

CONCLUSIONS

We report an up-to-date analysis elucidating the diagnostic accuracy of LNM detection by either CT, US, or in combination. Our work suggests dual CT + US to be the best for overall detection of LNM and CT to be preferable in detecting central LNM. The use of either CT or US alone may detect lateral LNM with acceptable accuracy, yet dual imaging (CT + US) significantly improved detection rates.

Predicting central lymph node metastasis in patients with papillary thyroid carcinoma based on ultrasound radiomic and morphological features analysis

OBJECTIVES

To build a combined model based on the ultrasound radiomic and morphological features, and evaluate its diagnostic performance for preoperative prediction of central lymph node metastasis (CLNM) in patients with papillary thyroid carcinoma (PTC).

METHOD

A total of 295 eligible patients, who underwent preoperative ultrasound scan and were pathologically diagnosed with unifocal PTC were included at our hospital from October 2019 to July 2022. According to ultrasound scanners, patients were divided into the training set (115 with CLNM; 97 without CLNM) and validation set (45 with CLNM; 38 without CLNM). Ultrasound radiomic, morphological, and combined models were constructed using multivariate logistic regression. The diagnostic performance was assessed by the area under the curve (AUC) of the receiver operating characteristic curve, accuracy, sensitivity, and specificity.

RESULTS

A combined model was built based on the morphology, boundary, length diameter, and radiomic score. The AUC was 0.960 (95% CI, 0.924-0.982) and 0.966 (95% CI, 0.901-0.993) in the training and validation set, respectively. Calibration curves showed good consistency between prediction and observation, and DCA demonstrated the clinical benefit of the combined model.

CONCLUSION

Based on ultrasound radiomic and morphological features, the combined model showed a good performance in predicting CLNM of patients with PTC preoperatively.

Extended Level IV Neck Dissection for Limited Prophylactic Clearance of Level V in Node-Positive Papillary Thyroid Carcinoma: a Homogenous Study Population

There is near consensus that prophylactic lateral neck dissection has no role in the management of differentiated thyroid cancer, but the extent of lateral neck dissection in differentiated thyroid cancer remains controversial, especially whether level V should be addressed or not. There is lot of heterogeneity in reporting of the management of level V in papillary thyroid cancer. We at our Institute address the lateral neck positive papillary thyroid cancer with selective neck dissection involving levels II-IV, performing extended level IV dissection with inclusion of the triangular area delineated by the sternocleidomastoid muscle, the clavicle, and the perpendicular line drawn to the clavicle from the point where the horizontal line at the level of cricoid cuts the posterior border of sternocleidomastoid muscle. Retrospective analysis of the departmental data set related to thyroidectomy with lateral neck dissection from 2013 to mid-2019 for papillary thyroid cancer, was carried out. Patients with recurrent papillary thyroid cancer were excluded as were patients with involvement of level V. Data related to the demography of patients, histological diagnosis, and postoperative complications were compiled and summarized. Note was made of the incidence of ipsilateral neck recurrence and the neck level involved with recurrence noted. Data was analyzed for fifty-two patients of non-recurrent papillary thyroid cancer who had undergone total thyroidectomy and lateral neck dissection involving levels II-IV, with extended dissection at level IV. It should be noted that none of the patients had clinical involvement of level V. Only two patients had lateral neck recurrence, both the recurrences were in level III, one on the ipsilateral side and the other on the contralateral side. Recurrence in the central compartment was noted in two patients, with one of these patients also having ipsilateral level III recurrence. One of the patients had distal metastasis to the lungs. Transient paresis of the unilateral vocal cords was noted in seven patients which got resolved within 2 months in all of them. Transient hypocalcemia was noted in four patients. Although our series has a small sample size with limited follow-up, it is one of the few studies in which prophylactic level V dissection has been studied in a homogenous study population of non-recurrent papillary thyroid cancer. Our study has shown that prophylactic dissection of level V may have a limited role, but further large multi-institutional studies need to be carried out to come up with a definite answer.

Radiologist versus Non-Radiologist Detection of Lymph Node Metastasis in Papillary Thyroid Carcinoma by Ultrasound: A Meta-Analysis

Papillary thyroid carcinoma (PTC) is the most common thyroid cancer worldwide and is known to spread to adjacent neck lymphatics. Lymph node metastasis (LNM) is a known predictor of disease recurrence and is an indicator for aggressive resection. Our study aims to determine if ultrasound sonographers’ degree of training influences overall LNM detection. PubMed, Embase, and Scopus articles were searched and screened for relevant articles. Two investigators independently screened and extracted the data. Diagnostic test parameters were determined for all studies, studies reported by radiologists, and studies reported by non-radiologists. The total sample size amounted to 5768 patients and 10,030 lymph nodes. Radiologists performed ultrasounds in 18 studies, while non-radiologists performed ultrasounds in seven studies, corresponding to 4442 and 1326 patients, respectively. The overall sensitivity of LNM detection by US was 59% (95%CI = 58–60%), and the overall specificity was 85% (95%CI = 84–86%). The sensitivity and specificity of US performed by radiologists were 58% and 86%, respectively. The sensitivity and specificity of US performed by non-radiologists were 62% and 78%, respectively. Summary receiver operating curve (sROC) found radiologists and non-radiologists to detect LNM on US with similar accuracy (p = 0.517). Our work suggests that both radiologists and non-radiologists alike detect overall LNM with high accuracy on US.

Macroscopic extranodal extension is an independent predictor of lung metastasis in papillary thyroid cancer

PURPOSE

Lymph node metastasis is common in patients with papillary thyroid cancer (PTC). Some metastatic lymph nodes may present extranodal extension (ENE). The clinical role of ENE in PTC has yet to be clearly identified. We evaluated macroscopic ENE as a potential prognostic indicator of lung metastasis in PTC.

PATIENTS AND METHODS

We identified 1140 consecutive patients who had PTC initially resected at our cancer center. Clinical data and pathological results were reviewed. Univariate and multivariate logistic regression analyses were used to figure out the association between clinicopathological variables and lung metastasis.

RESULTS

In this cohort, 51.7% of PTC patients had lymph node metastasis; 10.4% had macroscopic ENE positive nodes; 2.3% had lung metastasis. In patients with lymph node metastasis, the average number of positive nodes was 5.10 ± 4.91. Multivariable analysis of clinicopathological factors revealed that extrathyroidal extension (odds ratio [OR], 3.57; 95% CI, 1.41-9.04), macroscopic ENE (OR, 7.08; 95% CI, 2.54-19.74), and number of positive nodes were significantly associated with lung metastasis. Compared with 0-3 positive nodes, 7-9 positive nodes denoted a moderate risk of lung metastasis (OR, 4.53; 95% CI, 1.03-19.85). And 10 positive nodes or more indicated a high risk of lung metastasis (OR, 9.63; 95% CI, 2.65-35.02).

CONCLUSION

Macroscopic ENE could serve as a strong independent prognostic factor of lungmetastasis in PTC. More attention should be paid to patients with ENE positive nodes duringfollow-up.

Diagnostic Test Accuracy of Ultrasonography vs Computed Tomography for Papillary Thyroid Cancer Cervical Lymph Node Metastasis: A Systematic Review and Meta-analysis

Importance

The use of ultrasonography (US) vs cross-sectional imaging for preoperative evaluation of papillary thyroid cancer is debated.

Objective

To compare thyroid US and computed tomography (CT) in the preoperative evaluation of papillary thyroid cancer for cervical lymph node metastasis (CLNM), as well as extrathyroidal disease extension.

Data Sources

MEDLINE and Embase were searched from January 1, 2000, to July 18, 2020.

Study Selection

Studies reporting on the diagnostic accuracy of US and/or CT in individuals with treatment-naive papillary thyroid cancer for CLNM and/or extrathyroidal disease extension were included. The reference standard was defined as histopathology/cytology or imaging follow-up. Independent title and abstract review (2515 studies) followed by full-text review (145 studies) was completed by multiple investigators.

Data Extraction and Synthesis

PRISMA guidelines were followed. Methodologic and diagnostic accuracy data were abstracted independently by multiple investigators. Risk of bias assessment was conducted using the Quality Assessment of Diagnostic Accuracy Studies (QUADAS-2) tool independently and in duplicate. Bivariate random-effects model meta-analysis and multivariable meta-regression modeling was used.

Main Outcomes and Measures

Diagnostic test accuracy of US and CT of the neck for lateral and central compartment CLNM, as well as for extrathyroidal disease extension, determined prior to study commencement.

Results

A total of 47 studies encompassing 31 942 observations for thyroid cancer (12 771 with CLNM; 1747 with extrathyroidal thyroid extension) were included; 21 and 26 studies were at low and high risk for bias, respectively. Based on comparative design studies, US and CT demonstrated no significant difference in sensitivity (73% [95% CI, 64%-80%] and 77% [95% CI, 67%-85%], respectively; P = .11) or specificity (89% [95% CI, 80%-94%] and 88% [95% CI, 79%-94%], respectively; P = .79) for lateral compartment CLNM. For central compartment metastasis, sensitivity was higher in CT (39% [95% CI, 27%-52%]) vs US (28% [95% CI, 21%-36%]; P = .004), while specificity was higher in US (95% [95% CI, 92%-98%]) vs CT (87% [95% CI, 77%-93%]; P < .001). Ultrasonography demonstrated a sensitivity of 91% (95% CI, 81%-96%) and specificity of 47% (95% CI, 35%-60%) for extrathyroidal extension.

Conclusions and Relevance

The findings of this systematic review and meta-analysis suggest that further study is warranted of the role of CT for papillary thyroid cancer staging, possibly as an adjunct to US.

Prognostic implications of extranodal extension in papillary thyroid carcinomas: A propensity score matching analysis and proposal for incorporation into current tumor, lymph node, metastasis staging

BACKGROUND

The current American Joint Committee on Cancer tumor, lymph node, metastasis cancer staging system for papillary thyroid carcinoma places low weight on extranodal extension. This study examined the prognostic implications of extranodal extension in papillary thyroid carcinoma patients and attempted to design a new staging system incorporating extranodal extension.

METHODS

We reviewed data from 6,165 consecutive papillary thyroid carcinoma patients from 2012 to 2018. Patients with extrathyroidal extension or extranodal extension were included and then divided into 3 groups: extrathyroidal extension (papillary thyroid carcinoma with extrathyroidal extension but without extranodal extension, N = 457); extranodal extension (papillary thyroid carcinoma with extranodal extension but without extrathyroidal extension, N = 116); and extrathyroidal extension and extranodal extension (papillary thyroid carcinoma with both extrathyroidal extension and extranodal extension, N = 116). Recurrence-free survival and cancer-specific survival were compared before and after adjusting for differences using propensity score matching owing to observed heterogeneity in baseline characteristics in the original cohort. Recurrence-free survival and cancer-specific survival were also compared between patients with and without extranodal extension after matching at a 1:1 ratio. Cox proportional hazards regression analyses were used to identify the relationships of factors associated with structural recurrent disease in the node-positive subset. Then a new staging system incorporating extranodal extension was established, and the discrimination of the new staging system for recurrence-free survival and cancer-specific survival was investigated.

RESULTS

Of the 6,165 patients with papillary thyroid carcinoma, extrathyroidal extension was found in 573 (9.3%) patients, and extranodal extension was observed in 232 (3.8%) patients. The recurrence-free survival and cancer-specific survival rates of patients with extranodal extension were similar to those of patients with extrathyroidal extension (all P > .05). Patients with extrathyroidal extension and extranodal extension experienced worse recurrence-free survival than patients with extrathyroidal extension or extranodal extension and even worse cancer-specific survival than patients with extrathyroidal extension (all P < .05). The recurrence-free survival and cancer-specific survival rates of patients with extranodal extension were worse than those of patients without extranodal extension (P = .003; P = .048). Cox proportional hazards regression analysis demonstrated that after propensity score matching, extranodal extension (hazard ratio 1.911; 95% confidence interval 1.568-3.609; P < .001) remained an independent predictor of structural recurrent disease in patients with node-positive papillary thyroid carcinoma. After incorporating extranodal extension into the current tumor, lymph node, metastasis classification, the new staging system presented a better discrimination for recurrence-free survival and cancer-specific survival for those with lymph node metastasis.

CONCLUSION

Papillary thyroid carcinoma patients with extranodal extension present worse prognosis, and incorporating extranodal extension in tumor, lymph node, metastasis classification identifies poor-risk patients more accurately.

Analysis of Risk Factors of Level V Lymphatic Metastasis for Papillary Thyroid Carcinoma with pN1b

Objective

To explore the risk factors of level V lymphatic metastasis in papillary thyroid carcinoma (PTC) patients with pN1b.

Methods

Patients were selected if they presented with a suspicious level III or IV lymph node metastasis and underwent surgery by hemi or total thyroidectomy with a lymph node dissection (levels III, IV, VI, and VII). For these patients, if frozen section showed a positive level III or IV node, then levels II and V nodes were resected. Univariate analysis was performed using the chi-square test for some factors, including age, sex, tumor location, multifocal lesions, tumor size, local invasion of primary focus, status of cervical lymphatic metastasis, TNM staging, tumor deposits (independent tumor nodules), and the metastasis to more than 5 central lymph nodes. Then, the factors with statistical significance indicated by the above univariate analysis underwent multivariate analysis.

Results

Univariate analysis indicated that the level V lymphatic metastasis was significantly associated with simultaneous metastases to levels II, III, and IV, simultaneous metastases to levels III and IV, and tumor deposits (all p < 0.05), but it was not significantly associated with age, sex, tumor location, multifocal lesions, tumor size, local invasion of primary focus, other cervical lymphatic metastasis, TNM staging, and the metastases to more than 5 central lymph nodes (all p > 0.05). Multivariate analysis suggested that the simultaneous metastases to levels III and IV and tumor deposits were the risk factors of level V lymphatic metastasis.

Conclusion

The simultaneous metastases to levels III and IV and tumor deposits are independent risk factors of level V lymphatic metastasis. The patients with pN1b PTC who have simultaneous metastases to levels III and IV or/and tumor deposits may have the risk of level V lymph node metastasis.

Lateral Neck Dissection for Well-Differentiated Thyroid Carcinoma: Is Prophylactic Level V Neck Dissection Necessary? A Retrospective Cohort Study

OBJECTIVE

The presence of clinically detectable papillary thyroid carcinoma (PTC) metastases in the lateral neck is an indication for neck dissection (ND) and thyroidectomy. Although there is a consensus regarding the importance of therapeutic selective ND of involved levels II to IV in patients with clinically evident locoregional metastatic disease, the prognostic benefit of level V prophylactic ND remains debatable.

METHODS

All patients who underwent thyroidectomy with ND for metastatic PTC between 2006 and 2019 were included in a single-institution retrospective study. Preoperative characteristics at initial presentation, imaging workup, intraoperative findings, and the final histopathological reports were retrieved from the institutional database.

RESULTS

A total of 189 patients with locally advanced PTC were identified, of whom 22 (11.6%) patients underwent therapeutic selective ND at levels II to IV together with level V dissection due to clinical involvement. Comparison of the patients who were operated on level V to those who were not revealed no significant difference. The disease recurrence rate was 20.1% throughout an average follow-up of 5.1±3.1 years. No significant differences in recurrence rate were found between patients who underwent and those who did not undergo level V ND (22.7% vs 19.8%, P = .648). No recurrence at resected level V was detected during follow-up, while recurrence at level V was found in 4 (2.1%) patients who did not undergo level V dissection. Evidence of macroscopic and microscopic extrathyroidal extension was significant predictors of disease recurrence risk.

CONCLUSION

There were no significant associations between level V dissection and risk for recurrence. Recurrence at level V was rare (4/189 patients, 2.1%). Our study's findings suggest a low prophylactic benefit of an elective level V ND. Elective level V ND should not be done routinely when lateral ND is indicated but should rather be considered after careful evaluation in high-risk patients.

Prediction of level V metastases in papillary thyroid microcarcinoma: a single center analysis

Background

The rate of level V metastases is significantly low and the necessity of routine level V dissection for papillary thyroid microcarcinoma (PTMC) with clinically lateral lymph node metastasis (LNM) is still controversial.

Methods

This study enrolled 114 consecutive PTMC patients with clinically suspected lateral LNM (N1b) who underwent modified radical neck dissection (levels II to V) at Xiangya Hospital of Central South University from September 2016 to July 2019. Univariate and multivariate analyses were performed to investigate the predictive factors of level V metastasis. The area under the receiver operating characteristic (ROC) curve (AUC), accuracy, specificity and sensitivity were used to determine the predictive value.

Results

The overall and occult rate of level V metastasis were 29.82% (34/114) and 7.02% (8/114), respectively. Univariate analysis showed that level V metastasis was significantly associated with gross extrathyroidal extension (ETE), level IV metastasis and 2-level simultaneous metastasis (all P<0.05). Gross ETE (OR =11.916, 95% CI, 1.404-102.19; P=0.023) and level IV metastasis (OR =8.497, 95% CI, 2.119-34.065; P =0.03) served as independent predictors of level V metastasis in N1b PTMC patients. The sensitivity, specificity, accuracy, positive predictive value (PPV) and negative predictive value (NPV) of gross ETE and level IV metastasis in predicting the level V metastasis were 25.3% vs. 82.4%, 97.5% vs. 73.8%, 82.69% vs. 76.32%, 80% vs. 57.04% and 75% vs. 90.77%, respectively. The AUC of gross ETE was lower than level IV metastasis (0.605 vs. 0.781, P=0.041).

Conclusions

Routine level V dissection is necessary in N1b PTMC patients with level IV metastasis or gross ETE. Compared with gross ETE, level IV metastasis is superior in predicting level V metastasis.

Correlations of neck ultrasound and pathology in cervical lymph node of papillary thyroid carcinoma

Background: High-resolution sonography is becoming a method of choice for the detection and diagnosis of cervical lymph node metastasis in patients with papillary thyroid carcinoma (PTC). The purpose of this study is to assess the diagnostic accuracy of neck ultrasound (US) in the detection of lymph node metastases from PTC.Methods: Data for all patients with papillary thyroid cancers and preoperative neck US were reviewed retrospectively. The diagnostic accuracy of US was determined according to whether histologically confirmed cancer was present in surgical cervical lymph node specimens.Results: A total of 206 patients (149 central and 57 central and lateral lymph nodes dissection) were included. Their mean age was 56 years (14-88 years). Central and lateral lymph nodes were involved in 68% (n = 141 patients; 141/206) and 60% (n = 34 patients; 34/57) of cases, respectively. The sensitivity, specificity, positive predictive value and negative predictive value of US in predicting papillary thyroid carcinoma (PTC) metastasis in the central neck were 69%, 71%, 84% and 51% respectively, and in the lateral neck were 85%, 65%, 78% and 75% respectively.Conclusions: Preoperative neck US is a valuable tool in the detection of cervical lymph node metastases from papillary thyroid cancer and can provide reliable information to assist in surgical management.

Meta-analysis of ultrasound for cervical lymph nodes in papillary thyroid cancer: Diagnosis of central and lateral compartment nodal metastases

PURPOSE

To evaluate the performance of preoperative ultrasound in the diagnosis of cervical lymph nodes metastases (CLNM) of papillary thyroid cancer (PTC) and its value in assisting cervical lymph node dissection (CLND).

METHODS

PubMed, EMBASE and Cochrane Library databases were searched to identify relevant studies up to Sep. 2017. Overall sensitivity, specificity, and diagnostic odds ratio (DOR) were used to assess the diagnostic efficacy of ultrasound in detecting central and lateral CLNM of PTC.

RESULTS

Nineteen studies comprising 4014 patients were included in the meta-analysis. The pooled sensitivity, specificity, DOR and area under curve (AUC) of ultrasound in detecting central CLNM were 0.33 (95% confidence interval (95% CI): 0.31-0.35), 0.93 (95% CI: 0.92-0.94), 5.63 (95% CI: 3.50-9.04), and 0.69, respectively; and lateral CLNM were 0.70 (95% CI: 0.68-0.72), 0.84 (95% CI: 0.82-0.85), 18.7 (95% CI: 10.3-33.9) and 0.88, respectively. We found that the rate of central CLNM of PTC was 48.0%, and 36.2% of the dissected lymph nodes were metastatic, meanwhile, the rate of lateral CLNM of PTC was 59.2%, and 46.6% of the dissected lymph nodes were metastatic in the meta-analysis.

CONCLUSIONS

Preoperative ultrasound demonstrates poor sensitivity in the diagnosis of central CLNM, and good diagnostic efficacy for lateral CLNM of PTC. Prophylactic central CLND is recommended to PTC patients due to the high incidence of central CLNM and low diagnostic efficacy of ultrasound.

Nomogram for predicting level V lymph node metastases in papillary thyroid carcinoma with clinically lateral lymph node metastases: A large retrospective cohort study of 1037 patients from FDUSCC

Objective: Extensive lateral neck dissection (LND), especially routine level V dissection, may potentially increase morbidity and have no significant benefit to survival in patients with papillary thyroid carcinoma (PTC). Our study aimed to determine the pattern and risk factors for level V lymph node metastasis (LNM) and to develop an assessment model based on a nomogram for predicting whether level V dissection is necessary.

Methods: A total of 1037 PTC patients with clinically suspected LNM (N1b) who underwent total thyroidectomy (TT) with central LND and unilateral LND from 2011 to 2015 were retrospectively retrieved. Univariate and multivariate analyses were performed to examine risk factors associated with level V metastasis. A nomogram for predicting level V metastasis was established and internally validated.

Results: The overall rate of level V metastasis was 21.3% (221/1037). Unilateral central LNM (CLNM), level II/III/IV metastasis, extra nodal extension (ENE) and lymph node (LN) size ≥2 cm were found to be independent predictive factors for level V metastasis (P<0.05). In the nomogram, ENE was confirmed as the largest contributor to scores, followed by LN size, unilateral CLNM and level IV/III/II metastasis. The discrimination of the prediction model was 0.738 (95% confidence interval (CI): 0.703-0.773, P<0.001).

Conclusions: The rate of level V metastasis in N1b PTC patients was apparently lower than that of other levels. With the help of our nomogram, a modified lateral neck dissection encompassing levels II-V and a strictly postoperative evaluation may be indicated when the patient has a high score.

Routine Lateral Level V Dissection May Not Be Necessary for Papillary Thyroid Microcarcinoma With Lateral Lymph Node Metastasis: A Retrospective Study of 252 Cases

Background: Lateral lymph node metastasis (LLNM) is associated with distant metastasis, locoregional recurrence and cancer-specific mortality, although the prevalence of LLNM among patients with papillary thyroid microcarcinoma (PTMC) is relatively low. The potential benefits and risks of routine lateral level V dissection (LVD) for PTMC with LLNM have not been previously investigated. Methods: A total of 6,880 consecutive PTMC patients who underwent initial surgery at the First Hospital of Jilin University from January 2009 to July 2017 were retrospectively analyzed. A total of 252 N1b PTMC patients were enrolled in our study. Results: The overall and occult metastasis rates in level V lymph nodes were 21.4 and 6.4%, respectively. Patients with N1b PTMC who received LVD did not show a significantly lower disease-free survival (DFS) than that of patients who did not receive LVD [hazard ratio = 1.11 (CI 0.38-3.21); p = 0.85]. Meanwhile, LVD simultaneously increased the hospital stay and cost (p = 0.03; 0.02). Multivariate logistic regression analysis revealed that 3-level simultaneous metastasis in the lateral neck was an independent risk factor for level V metastasis [odds ratio = 8.6 (CI 1.42-51.72); p = 0.02]. Conclusions: Because of the low metastasis rate in level V lymph nodes, the lack of benefit for recurrence, the longer hospital stay and the higher cost associated with LVD, N1b PTMC patients without clinical level V metastasis may not need to undergo routine dissection. Prophylactic LVD may be recommended only for patients with N1b PTMC with 3-level simultaneous metastasis.

Establishing a prediction model for lateral neck lymph node metastasis in patients with papillary thyroid carcinoma

This study aimed to establish a model for predicting lateral neck lymph node metastasis in patients with papillary thyroid carcinoma. A total of 106 patients with papillary thyroid carcinoma undergoing initial treatment of neck lymph node dissection (including central and lateral neck lymph nodes) at the thyroid surgery department were enrolled from January 2009 to April 2017. Logistic regression analysis was used to screen the factors influencing lateral neck lymph node metastasis and develop a prediction model. The receiver operating characteristic curve was used to evaluate the predictive power and boundary value of the model for lateral neck lymph node metastasis. Prediction model: Logistic(P) = -5.699 + 0.681 × _(TSH) + 0.342 × _{(Metastatic rate of central lymph nodes)} + 1.463 × _{(Combined with Hashimoto's disease)} + 1.525 × _{(Number of tumors)}. When logistic (P) was ≥ 0.821, it was predicted that lateral neck lymph node metastasis occurred in patients with papillary thyroid carcinoma. When logistic (P) was <0.821, it was predicted that no metastasis was found in the lateral neck lymph node. The prediction accuracy was 78.3%. The model helped in evaluating lateral neck lymph node metastasis in patients with papillary thyroid carcinoma. Also, it had significance in determining reasonable surgical range, reducing unnecessary lateral neck lymph node dissection, and further improving the quality of life of patients.

Retrospective analysis of prognostic factors in patients of papillary thyroid microcarcinoma

We performed a retrospective chart review of 245 patients with papillary thyroid microcarcinoma (PTMC) to define factors linked to central lymph node metastasis and thus prognosis. Univariate and multivariate analyses showed that being male (p < 0.001), age <45 years at diagnosis (p = 0.045), maximum tumor size > 5 mm (p = 0.030), multifocal tumor (p = 0.040) and tumor envelope invasion (p < 0.001) were all independent risk factors for central compartment lymph node metastasis. Unifocal lesions at the thyroid gland’s upper pole, middle and lower pole, had lymph node metastasis rates of 22.7%, 14.0% and 35.0%, respectively (p = 0.048). The rate of central lymph node metastasis was much higher when there was bilateral thyroid involvement than with multifocal unilateral lesions (58.6% vs 37.5%; p = 0.040). These results suggest that for patients at low risk of central lymph node metastasis, unilateral thyroid lobe and isthmus resection is sufficient. However, for patients at high risk of central lymph node metastasis, central lymph node dissection increases the likelihood of complete tumor excision.

Pattern of and clinicopathologic risk factors for lateral lymph node metastases in papillary thyroid carcinoma patients with lateral cervical lymphadenopathy

The surgical extension of lateral neck dissection (LND) in papillary thyroid carcinoma (PTC) with clinical lateral lymph node metastases (LLNM) remains controversial. The aim of this study was to explore the pattern of and clinicopathologic risk factors for LLNM in PTC with clinical unilateral LND to determine the rational extent of therapeutic LND.This retrospective study reviewed the records of 246 consecutive patients with PTC who simultaneously underwent total thyroidectomy, bilateral central lymph node dissection, and unilateral therapeutic LND. The frequency and pattern of LLNM were analyzed.Grossly, LLNM were present in 80.9% of patients, and level II to V lymph node metastases (LNM) were present in 45.9%, 62.6%, 56.1%, and 11.8% patients, respectively. Superior tumor location, extrathyroidal extension, and ipsilateral, contralateral, and bilateral central LNM (CLNM) were independent risk factors for gross LLNM. Age ≥45 years, superior lobe tumors, extrathyroidal extension, and ipsilateral and contralateral CLNM were independent risk factors for level II LNM. Age ≥45 years, superior and middle lobe tumors, extrathyroidal extension, and ipsilateral CLNM were independent risk factors for level III LNM. Superior lobe tumors and ipsilateral, contralateral, and bilateral CLNM were independent risk factors for level IV LNM. Only contralateral CLNM was an independent risk factor for level V LNM.In PTC patients with clinical LLNM, the predominant sites of LLNM were levels II to IV and not level V. Therapeutic elective LND should include the lateral nodal levels associated with independent risk factors, especially superior tumors location and CLNM.

Therapeutic lateral neck dissection in well-differentiated thyroid cancer: Analysis on factors predicting distribution of positive nodes and prognosis

BACKGROUND

Neck dissection is considered the treatment of choice in patients with lateral neck metastases from well-differentiated thyroid cancer.

METHODS

A multicenter, retrospective review of patients who underwent therapeutic lateral neck dissection for well-differentiated thyroid carcinoma was carried out.

RESULTS

The study included a total of 405 lateral neck dissections performed in 352 patients; 197 women (56%) and 155 men (44%). When considering ipsilateral neck metastases, levels IIa, IIb, III, IV, Va, Vb, and V (not otherwise specified) were involved in 42%, 6%, 73%, 67%, 11%, 31%, and 35% of cases, respectively. Five-year and 10-year overall survival (OS) were 93% and 81%, respectively. Age >55 years, pathologic T (pT)4 category, tumor diameter >4 cm, aggressive variants of well-differentiated thyroid carcinoma, endovascular invasion, and number of positive nodes >5 turned out to be the most important prognostic factors.

CONCLUSION

Neck dissection is a valid treatment option in the presence of neck metastasis from well-differentiated thyroid carcinoma. Levels IIa, III, IV, and Vb should always be removed.

Extranodal extension of lymph node metastasis as a prognostic indicator of recurrence and survival in papillary thyroid carcinoma

BACKGROUND AND OBJECTIVES

Stratification of extranodal extension (ENE) extent has the potential to improve the accuracy of risk estimations in papillary thyroid carcinoma (PTC). This study examined the prognostic importance of nodal factors, including ENE, in PTC patients.

METHODS

This study enrolled 2071 consecutive patients with treatment-naïve PTC who underwent thyroidectomy between 2006 and 2010. Microscopic/macroscopic ENE was determined by pathological and operative findings. Univariate and multivariate analyses were used to identify the relationship of factors with recurrence and survival in all study patients and in the node-positive subset.

RESULTS

Of 2071 patients, 975 (47.1%) had positive lymph nodes, and 271 (13.1%) and 70 (3.4%) had microscopic and macroscopic ENE, respectively. During a median follow-up of 96 months, 114 (5.5%) patients had post-treatment recurrence. Multivariate analyses showed that, in all patients, the number of positive nodes, lymph node ratio, ENE status, and ATA risk group were independent variables affecting recurrence (P < 0.05). T4 and macroscopic ENE were independent variables associated with shorter overall survival (P < 0.05). Macroscopic ENE was significantly associated with macroscopic extrathyroidal extension.

CONCLUSION

Macroscopic ENE has a significant adverse impact on recurrence and survival after treatment for PTC. ENE is considered a high risk factor for recurrence.

Risk factors for level V lymph node metastases in solitary papillary thyroid carcinoma with clinically lateral lymph node metastases

The extent of lateral neck dissection (LND) in surgical resection of papillary thyroid carcinoma (PTC) with clinically lateral LNM (LLNM) remains controversial. We aimed to explore the frequency of and risk factors for level V LNM in patients with solitary PTC and clinically LLNM. To analyze the frequency and risk factors for level V LNM, we retrospectively reviewed 220 solitary PTC patients who underwent total thyroidectomy, bilateral central neck dissection, and therapeutic LND. LLNM were present in 82.3% patients, and levels II-V LNM were present in 45.9%, 62.7%, 55.5%, and 12.3% patients, respectively. Ipsilateral level V LNM was significantly associated with tumor size >10 mm, extrathyroidal extension, ipsilateral central LNM ratio ≥50%, and contralateral central LNM (CLNM), bilateral CLNM, and simultaneous levels II-IV LNM. Contralateral CLNM was an independent risk factor for level V LNM. In patients with solitary PTC and clinically LLNM, level V LNM was relatively uncommon. Therefore, routine level V lymphadenectomy may be unnecessary in these patients unless level V LNM is suspected on preoperative examination or associated risk factors, especially contralateral CLNM, are present.

The Impact of Metastatic Lymph Nodes on Risk Stratification in Differentiated Thyroid Cancer: Have We Reached a Higher Level of Understanding?

BACKGROUND

The revised American Thyroid Association (ATA) management guidelines for differentiated thyroid cancer emphasize a variety of clinicopathologic features of metastatic lymph nodes in determining the risk of recurrence. The mere presence of a positive node is not sufficient to confer reliable prognostic significance. The number and size of lymph nodes, as well as the presence of extranodal extension (ENE), impact risk stratification. Moreover, the presence of clinically evident lymph nodes is important for determining risk of recurrence. A patient's place on the risk spectrum has ramifications for the management of differentiated thyroid cancer. However, there are inherent inconsistencies in the identification and characterization of metastatic lymph nodes. Moreover, the significance of ENE must be clarified.

SUMMARY

There are many obstacles to the consistent reporting of metastatic lymph nodes. What constitutes a "clinically evident" lymph node has not been well defined, lacks precision, and varies depending on clinical context, as well as the experience of the surgeon and the ultrasonographer. The number of lymph nodes sampled by surgeons and reported by pathologists may vary from institution to institution. The literature on ENE has been limited by the fact that the definition of ENE has not been standardized. Nevertheless, 17/19 manuscripts reviewed herein suggest that ENE confers a worse prognosis. The ATA risk stratification for metastatic lymph nodes published in the 2015 guidelines combines clinicopathological features that are variably identified and reported across institutions. This review brings into question the significance of the number of nodes with ENE, a factor that is used as an important stratifying variable in the latest guidelines.

CONCLUSIONS

Metastatic lymph nodes do not all carry the same prognostic significance, but a risk assignment based on the ATA guidelines is limited by a lack of standardization in clinical and pathologic definitions, lymph node sampling, and reporting. This study reviews the limitations of prior studies on ENE and concludes that the body of the evidence reported in those studies suggests that ENE increases the risk of recurrence. The impact of ENE in lymph nodes in thyroid cancer risk stratification should be reconsidered.

Candidates for limited lateral neck dissection among patients with metastatic papillary thyroid carcinoma

BACKGROUND

Papillary thyroid carcinoma (PTC) is associated with an excellent prognosis but frequently spreads to regional lymph nodes. The extent of neck dissection, particularly routine level II or V lymphadenectomy, is still controversial as it may lead to spinal accessory nerve injury and associated postoperative morbidities. We assessed the diagnostic value of preoperative ultrasonography (US) plus computed tomography (CT) for detecting metastatic lymph nodes and for identifying predictors of level II or V metastasis in patients with PTC.

METHODS

The results of US and CT were compared with histopathologic findings at various neck levels in 209 previously untreated PTC patients with lateral cervical nodal metastases who underwent total thyroidectomy with central and lateral neck dissection. Clinicopathologic predictors for level II or V metastases were identified.

RESULTS

Pathologic metastases to level II and V were observed in 53.6 and 25.4 % of patients, respectively. Occult metastases were found in 34.5 and 16.8 %, respectively. The sensitivities of US plus CT for levels II and V were 64.6 and 50.9 %, respectively. Image-based, isolated lateral level IV involvement and macroscopic extranodal extension were independently associated with level II metastasis or either level II or V metastasis (p < 0.01). Macroscopic extranodal extension was also independently associated with level V metastasis (p = 0.001).

CONCLUSIONS

Patients with image-based, isolated lateral level IV involvement and no macroscopic extranodal extension are potential candidates for limited level III-IV dissection or prophylactic level II lymphadenectomy omission. Level V lymphadenectomy may be omitted in patients without macroscopic extranodal extension.

Minimally-invasive endoscopically-assisted neck dissection for lateral cervical metastases of thyroid papillary carcinoma

Traditional open operations for lateral neck dissection in patients with papillary thyroid carcinoma leave an unsightly scar. We report complete lateral neck dissection and thyroidectomy for papillary thyroid carcinoma using an endoscopically-assisted approach through a small incision, and evaluate its feasibility and safety. Between March 2010 and January 2013, 6 patients with no definite metastases to the lymph nodes at levels II-IV, and 20 with definite metastases to the lymph nodes at levels II-V were selected. Thyroidectomy, dissection of the central compartment (level VI), and ipsilateral level II-IV and II-V neck dissections were done through a small incision in the neck. The steps of endoscopic lateral neck dissection were similar to those of conventional operations. The mean operating time for the whole procedure was 3.57 hours (range 2.5 - 5.0). It was successful in all patients and there were no serious complications or serious blood loss. A total of 21 patients had lymph node metastases in the central and lateral zones. The mean yield of lymph nodes was 38.6 (range 16-61). There was no evidence of residual or recurrent disease at follow-up, and the cosmetic result was excellent. Minimally invasive, video-assisted comprehensive neck dissection for metastatic papillary thyroid carcinoma is feasible and safe, and has excellent cosmetic results. Further studies with a larger number of patients and long-term follow-up are needed to verify its oncological validity.

Extrathyroidal extension predicts extranodal extension in patients with positive lymph nodes: an important association that may affect clinical management

BACKGROUND

While there is consensus that significant extrathyroidal extension (ETE) (T4) should upstage a patient with well-differentiated thyroid cancer, the importance of minimal ETE (T3) remains controversial. Additionally, the importance of nodal metastases on prognosis has come under scrutiny. Recent publications highlight the importance of size, number of positive nodes, and, in particular, the presence of extranodal extension (ENE) as measures of disease aggressiveness. In this study, we examined whether ETE is a predictor of ENE.

METHODS

A retrospective review was conducted from January 2004 to March 2013. All node-positive patients who underwent total or completion thyroidectomy were included. Histologic features defined by the College of American Pathologists (CAP) protocol for thyroid carcinoma were recorded.

RESULTS

A total of 193 patients qualified for review. Patients who were found to have ETE were 12 times more likely to have lymph nodes in the primary setting with ENE than patients with intrathyroidal primary tumors (p<0.000). After exclusion of all T4 cases (n=6), patients with minimal ETE were 13 times more likely to have ENE than those with no ETE (p<0.000). Twenty percent of microcarcinomas with ETE demonstrated ENE.

CONCLUSION

We have found that the biology of the primary tumor is conferred to the lymph node in that the presence of ETE leads to a significantly higher incidence of ENE. Awareness of this relationship should be accounted for in the management of primary and recurrent lymph nodes. This study shows that minimal ETE is a significant predictor of ENE. Although long-term survival and recurrence follow-up is not available for the majority of patients in this series, the presence of ENE as a surrogate for more aggressive disease biology and its strong association with minimal ETE supports the upstaging of patients with minimal ETE.