The extent of lymph node yield in central neck dissection can be affected by preoperative and intraoperative assessment and alter the prognosis of papillary thyroid carcinoma

The lymph node yield in the initial lateral neck dissection predicts recurrence in the lateral neck of papillary thyroid carcinoma: a revision surgery cohort study

BACKGROUND

This study aimed to evaluate the relationship between lateral lymph node yield (LLNY) and the ratio of lateral positive lymph nodes to lymph node yield (LPLR) from initial lateral neck dissection (LND) in patients with papillary thyroid carcinoma (PTC), as well as the risk of recurrence in patients undergoing LND reoperations.

METHODS

This retrospective cohort study enrolled patients with PTC who underwent revision LND between 1 January 2012, and 31 December 2021. The initial and revised clinical data were retrieved. Patient demographics, clinicopathological features, clinical records, and follow-up information were also reviewed. LLNY and LPLR were determined during the initial LND.

RESULTS

In total, 156 patients with PTC were included in this study, with a median follow-up of 36.5 months; 107 had recurrent lateral neck disease. The optimal LLNY and LPLR cutoff values for recurrent/persistent disease were 24.5 and 32.74%, respectively. The high-risk group (LLNY<25) had the lowest recurrence-free survival rate compared with to moderate-risk group (LLNY≥25, LPLR≥32.74%) and low-risk group (LLNY≥25, LPLR<32.74%) ( P <0.001). The moderate-risk group had lower recurrence-free survival than the low-risk group. Multivariate analysis revealed that an LLNY less than 25 in the initial LND was an independent risk factor for recurrence/persistence of lateral neck ( P <0.001).

CONCLUSIONS

This study identified that LLNY and LPLR were associated with recurrence/persistence in PTC patients at the time of revision surgery was performed.

Prognostic Factors for Excellent Response to Initial Therapy in Patients With Papillary Thyroid Cancer From a Prospective Multicenter Study

Prognostic factors for excellent response (ER) to initial therapy in patients with papillary thyroid cancer (PTC) have not been determined. In this study, we investigated the response to initial therapy in PTC patients and independent prognostic factors for ER in a prospective multicenter study in China. A total of 506 PTC patients from nine centers in China were enrolled in this study, all of whom underwent total or near total thyroidectomy with lymph node dissection and subsequent radioiodine therapy. Univariate and multivariable logistic regression analyses were carried out to determine the independent prognostic factors for ER. The optimal cutoff value of the number of metastatic lymph nodes for predicting ER was determined by the receiver operating characteristic curve. A total of 139 patients (27.5%) achieved ER after initial therapy. Extrathyroidal extension, the number of metastatic lymph nodes, and preablative-stimulated thyroglobulin (Ps-Tg) were independent risk factors for ER for the entire population. In a subgroup analysis, extrathyroidal extension and Ps-Tg were independent risk factors for ER in pathological N1a patients, while the number of metastatic lymph nodes and Ps-Tg were independent risk factors for ER in pathological N1b patients. The appropriate cutoff values of the number of metastatic lymph nodes in predicting ER were 5 and 13 for the entire population and pathological N1b PTC patients, respectively. PTC patients with more metastatic lymph nodes were more likely to fail to achieve ER. Extrathyroidal extension, the number of metastatic lymph nodes, and Ps-Tg were important prognostic factors for ER after initial therapy in PTC patients.

Comparison of Supraclavicular Oblique Incision With Traditional Low Collar Incision Approach for Thyroidectomy in Differentiated Thyroid Cancer

Background

Various incisions and approaches for thyroidectomy have been developed to treat differentiated thyroid cancer (DTC). Supraclavicular oblique incision (SOI) thyroidectomy (SOIT) has been applied in DTC patients over the past ten years. However, the safety and efficacy of this approach were yet to be confirmed.

Aim

This study aimed to compare the surgical and patient-related outcomes between SOIT and traditional low collar incision thyroidectomy (TLCIT) in patients with DTC.

Methods

We retrospectively screened all patients with DTC who received thyroid lobectomy from October 2020 to October 2021. The surgical results and patient-related outcomes assessed at 1 and 6 months after surgery by questionnaire were compared between the SOIT and TLCIT groups.

Results

A total of 128 patients were included in this study, of whom 38 patients (30.5%) were operated on with SOIT and 89 patients (69.5%) with TLCIT. There was no significant difference in demographic characteristics and thyroid features between the two groups. Despite comparable operative time (61.9 ± 12.1 vs. 59.9 ± 15.0 min, p = 0.425), the SOIT group had a smaller neck incision (4.4 ± 0.7 vs. 5.0 ± 1.0 cm, p = 0.002), a shorter duration of postoperative drainage (2.4 ± 0.5 vs. 2.7 ± 0.9 days, p = 0.019), less volume of postoperative drainage (48.4 ± 24.6 vs. 60.3 ± 22.8 ml, p = 0.040), and shorter postoperative hospitalization (3.2 ± 0.5 vs. 3.6 ± 0.9 days p = 0.006), as compared with the TLCIT group. At 1-month follow-up after surgery, SOIT showed better performance in preventing hypoparathyroidism (p = 0.026) and abnormal neck sensation (p = 0.010) and in improving cosmetic satisfaction (p = 0.036) than TLCIT. At 6-month follow-up, SOIT was feedback with better cosmetic satisfaction (p < 0.001) and a lower percent of abnormal neck sensation (p = 0.031) or movement (p = 0.005).

Conclusion

Our study suggests that minimally invasive surgery using the SOI provides superior surgical and patient-related outcomes compared with surgery using a traditional low collar incision (TLCI) in patients with DTC.

Lymphatic Vessel Invasion in Routine Pathology Reports of Papillary Thyroid Cancer

Purpose

It is not mandatory to report lymphatic vessel invasion in pathology reports of papillary thyroid cancer (PTC) according to the current Union for International Cancer Control (UICC) TNM (tumor, nodes, and metastases) classification. However, there is some evidence for its correlation with lymph node metastasis (LNM) and prognosis. The aim of this study was to explore the clinical implication of lymphatic vessel invasion documentation of PTC because pathology reports play a pivotal role in postsurgical clinical decision-making in endocrine tumor boards.

Methods

Patients undergoing postoperative radioiodine treatment for PTC at the University Hospital of Cologne, Germany between December 2015 and March 2020 were identified. Pathology reports were screened for documentation of lymphatic vessel invasion. Demographics and clinicopathologic data of patients documented, including lymphatic vessel invasion and lymph nodal involvement were analyzed.

Results

A total of 578 patients were identified and included. Lymphatic vessel invasion was reported in pathology reports of 366 (63.3%) and omitted in 112 (36.7%) patients. Positive lymphatic vessel invasion (L1) was diagnosed in 67 (18.3%) of 366 patients and was documented as absent (L0) in 299 (81.7%) patients. Lymph nodal (N) status was positive (N+) in 126 (45.6%) and negative (N0) in 150 (54.3%) of these patients. In 54 (80.6%) L1 cases N+ status and in 137 (65.6%) L0 cases N0 status was diagnosed. In 13 (19.4%) cases with L1 status, there were no LNMs (L1 N0). In total, 72 (34.4%) patients had LNM despite L0 status (L0 N+). The sensitivity and specificity of LVI reporting for LNM were 0.42 and 0.91, respectively.

Conclusion

In routine pathology reports of PTC used for indication to postoperative radioiodine treatment by a German endocrine tumor board, lymphatic vessel invasion was found to be reported inconsistently and mostly as L0. L1 diagnoses, however, reliably correlated with reported LNM and might, thus, be relevant for clinical decision-making. For this reason, we advocate for standardized pathologic reassessment of lymphatic vessel invasion, in particular for cases where lymph nodes are not included in the pathologic specimen and if L0 is documented.

The effect of intraoperative neuromonitoring on the number of lymph nodes excised and recurrence when applied during neck dissection in cases of papillary thyroid cancer

Purpose

The aim of this study was to evaluate the effect of neuromonitoring on the number of lymph nodes (LNs) removed when applied during neck dissection.

Methods

A total of 166 patients receiving neck dissection due to papillary thyroid cancer were separated into 2 groups (monitoring group, n = 76; non-monitoring group, n = 90).

Results

The number of LNs dissected was observed to be statistically significantly higher in the monitoring group (P = 0.001), and the difference between the groups in the number of positive LNs was significant (P = 0.031). There was seen to be a negative relationship between the number of positive LNs dissected and recurrence (r = –0.404, P = 0.005).

Conclusion

Intraoperative neuromonitoring during neck dissection makes a positive contribution to the prevention of the development of recurrence by increasing the number of LNs excised and the number of metastatic LNs.

Risk probability model for residual metastatic lymph node in patients with papillary thyroid microcarcinoma undergoing cervical central lymph node dissection

To establish a risk probability model for residual metastatic lymph nodes in patients with papillary thyroid microcarcinoma (PTMC) after cervical central lymph node dissection (CLND). The clinical data of patients with PTMC treated in the First Affiliated Hospital of Kunming Medical University from 2007 to 2020 were retrospectively reviewed. All patients underwent thyroidectomy with CLND, and at least one lymph node was examined. Based on the distribution characteristics of metastatic lymph nodes from this retrospective cohort, a probabilistic model for the risk of residual metastatic lymph node was established. β-Binomial distribution was used to estimate the probability of residual metastatic lymph node as a function of the number of lymph nodes examined. Among 5399 patients included in the probabilistic model, central lymph node metastases were observed in 1664 cases (30.8%). After model correction, the real lymph node metastasis rate increased from 30.8% to 38.9%. The probability of false negative of central lymph node was estimated to be 31.3% for patients with a single node examined, while decreased to 10.0% and 4.9% when 7 and 12 nodes were examined, respectively. In the sensitivity analysis limited to patients with or without Hashimoto thyroiditis, the performance of probability model was also satisfactory. The established risk probability model in this study quantifies the risk of residual metastatic lymph nodes after CLND in patients with PTMC, which can be used as complementary indicators for the risk of recurrence/persistence disease at postoperative evaluation. The study also provides a new method to evaluate the impact of residual metastatic lymph nodes on the prognosis of tumor patients through retrospective data.

Lymph node yield in the initial central neck dissection (CND) associated with the risk of recurrence in papillary thyroid cancer: A reoperative CND cohort study

BACKGROUND

To evaluate the relationship between lymph node yield (LNY) from the initial central neck dissection (CND) and the risk of recurrence in patients undergoing reoperative CND for papillary thyroid cancer (PTC).

METHOD

We reviewed clinical data from all patients with pathologically proven PTC who underwent central neck and/or lateral neck dissection reoperations at Nanfang Hospital between 2012 and 2020. Patient demographics, tumor characteristics, clinical data and follow-up information were obtained. In the initial CND, the total number of lymph nodes removed (LNY), total positive nodes removed, and the percentage of positive lymph nodes to the number of lymph nodes removed (PLN%) were determined.

RESULTS

A total of 162 patients were included in the study, with a median follow-up of 44 months. 62 had central neck disease recurrence. The optimal LNY and PLN% cut-off values for recurrence were 11 and 65%, respectively. Group 2 (LNY ≥ 11, PLN% < 65%) showed a significantly higher RFS rate than group 1 (LNY < 11 and PLN% < 65%; P < 0.001), group 3 (LNY < 11, PLN% ≥ 65%; P < 0.001), and group 4 (LNY ≥ 11, PLN% ≥ 65%; P = 0.038). Furthermore, group 4 had a higher RFS rate than group 1 (P = 0.008) and group 3 (P = 0.001). Multivariate analysis revealed that LNY < 11 in the central neck was an independent risk factor for recurrence/persistence in the initial surgery (P < 0.001).

CONCLUSION

Higher LNY in central and neck dissections is associated with lower papillary thyroid cancer recurrence rates, which was confirmed by a reoperative CND procedure. To minimize the risk of recurrence and the need for secondary therapy, surgeons should perform compartment-oriented CNDs when indicated.

Clinical implications of Delphian lymph node metastasis in papillary thyroid carcinoma

Background

As is known, identifying risk factors precisely for lymph node metastasis (LNM) plays a vital role in initial treatment for papillary thyroid carcinoma (PTC). Nonetheless, whether Delphian lymph node (DLN) metastasis has value in predicting LNM remains an open question. This study covered a sample of 1,575 patients, which is the largest sample group so far, aiming to assess the predictive validity of DLN metastasis in PTC.

Methods

This retrospective cohort study was conducted with 1,575 eligible PTC patients who underwent thyroid operation between July 2013 and December 2018 and clinicopathologic parameters of patients with DLN metastasis were compared with those without DLN metastasis.

Results

The incidence of DLN metastasis, according to our research samples, is 24.4% (384/1,575 patients). And results show that DLN positivity was closely associated with adverse prognostic factors including younger age, larger tumor size, extrathyroid extension, tumor location in the isthmus or upper lobe of the thyroid, number of LNM >5, higher recurrence. After carefully adjusting important confounding factors, we find that in multivariate logistic regression analyses, DLN metastasis is an independent predictor for both central LNM (CLNM, adjusted OR =7.81, P<0.001) and lateral LNM (LLNM, adjusted OR =3.40, P<0.001). Moreover, the stratified analyses also show convincing evidence of a positive correlation between DLN metastasis and LNM in levels II-IV in the vast majority of subgroups.

Conclusions

The present study suggests that DLN metastasis is an independent risk factor for CLNM and LLNM of levels II-IV. The cervical lymph nodes should be meticulously evaluated to guide tailored treatment during operation in patients with DLN involvement.

Management of Lateral Multiple-Level Metastasis in N1b Papillary Thyroid Microcarcinoma

Background: The optimal extent of therapeutic lateral neck dissection (LND) in the management of N1b papillary thyroid microcarcinoma (PTMC) is still under debate in clinical practice. In this light, our study aims to explore the incidence, patterns, and predictive factors of the lateral multiple-level metastasis in N1b PTMC patients.

Methods: The clinical records of 142 patients diagnosed with N1b PTMC who underwent therapeutic LND from July 2015 to November 2018 at our institution were retrospectively reviewed. Univariate and multivariate analyses were conducted to examine the predictive factors associated with lateral multiple-level metastasis. The recurrence-free survival was analyzed and confirmed by Kaplan–Meier plots and log-rank test.

Results: The overall frequency of lateral multiple-level metastasis was 50.7% in N1b PTMC patients, and two-level to four-level simultaneous metastasis were present in 26.8, 17.6, and 6.3% patients, respectively. Extrathyroidal extension (ETE) (OR = 5.79, 95% CI, 1.36–24.59; P = 0.017) and the central metastatic lymph node ratio (CLNR) with values equal or higher than 0.61 (OR = 6.18, 95% CI, 2.53–15.09; P < 0.001) served as independent predictors of multiple-level metastasis in N1b PTMC patients. Moreover, locoregional recurrence was significantly higher in the selective neck dissection (SND) group compared to the modified radical neck dissection (MRND) one (HR = 3.65, 95% CI, 1.11–12.00; P = 0.03).

Conclusion: Our results show that the lateral multiple-level metastasis was relatively common, and we suggest MRND to be considered for N1b PTMC patients with ETE or CLNR equal or higher than 0.61.

The extent of lymph node yield in central neck dissection can be affected by preoperative and intraoperative assessment and alter the prognosis of papillary thyroid carcinoma

Background

Lymph node yield (LNY) was implemented in the stratification of papillary thyroid cancer (PTC) patients. The effect of LNY may be related to the extent of surgery. This study aims to identify influencing factors for LNY in central compartment neck dissection (CND).

Methods

Data of 13 712 consecutive PTC patients were analyzed retrospectively. Risk factors for LNY in CND and distribution characteristics of LNY were evaluated. Its relationship with prognosis was studied in another cohort of 136 cases.

Results

LNY in therapeutic CND was significantly higher than prophylactic CND (Unilateral: 5.55 ± 3.79 vs 3.41 ± 2.77; Bilateral: 8.90 ± 5.10 vs 6.47 ± 4.17, P < .001). Other independent factors included extranodal extension (ETE), tumor size, and concurrent Hashimoto's thyroiditis. The inconsistency distribution of LNY in bilateral CND was associated with preoperative and intraoperative assessment. Patients with significant difference between major and minor LNY suffered from poorer prognosis (10y‐RFS: 58.3% vs 92.0%; HR = 6.719, 95%, P < .0001).

Conclusions

CND surgical procedure, ETE, and Hashimoto's thyroiditis were independent factors of LNY. Inconsistent distribution of LNY was associated with prognosis of bilateral PTC patients. The impact of preoperative and intraoperative assessment on the actual extent of CND can be used to explain the relationship between LNY and PTC prognosis.