Lymph node density in papillary thyroid carcinoma is a prognostic factor after adjusting for pathological stage

Lymph node ratio as a tool to stratify patients with N1b papillary thyroid cancer

BACKGROUND

The prognostic significance of lymph node ratio (LNR) in N1b papillary thyroid cancer is unclear. Therefore, the impact of LNR on disease-specific mortality (DSM) and overall survival (OS) in patients with N1b papillary thyroid cancer (PTC) needs to be defined.

METHODS

We used the Surveillance, Epidemiology, and End Results (SEER) database of patients who had undergone thyroidectomy and lymph node dissection. Factors associated with DSM and OS were analyzed and identified using univariate and multivariate Cox proportional risk models. X-tile software was used to find the best cutoff value of LNR. Kaplan-Meier estimates for DSM were plotted for LNR and were compared with the log-rank test. The ROC curve evaluated the validity of the model.

RESULTS

A total of 3223 patients with N1b PTC were identified in the SEER database between 1975 and 2019. The best cutoff value for LNR was 0.6. The multivariate Cox proportional risk model showed that age, race, T3/T4 classification, distant metastasis, extent of surgery, number of metastatic lymph nodes, and LNR > 0.6 were independent risk factors for DSM (all p < 0.05). Age, sex, T4 classification, distant metastasis, extent of surgery, and LNR > 0.6 were independent risk factors for OS (all p < 0.05). The Kaplan-Meier method plotted a cumulative risk curve and showed that patients with LNR > 0.6 had a significantly higher risk of DSM than patients with LNR ≤ 0.6 (p = 0.002).

CONCLUSION

LNR was a powerful predictor of DSM and OS in N1b PTC patients. LNR could be a useful tool for the stratification of PTC patients with lateral neck metastases.

Mitoxantrone hydrochloride injection for tracing helps to decrease parathyroid gland resection and increase lymph node yield in thyroid cancer surgery: a randomized clinical trial

The identification and preservation of parathyroid glands (PGs) during thyroid surgery can be challenging. Many techniques have been developed to help surgeons find PGs. We have developed a novel mitoxantrone hydrochloride injection that can be used for lymphatic targeting. After local application during surgery, mitoxantrone hydrochloride injection for tracing (MHI) helps surgeons better identify and preserve PGs and helps pathologists find more lymph nodes. We conducted an open-label, multicenter, randomized clinical trial (CTR20171137) in six centers in China from 08/2017 to 12/2018. Patients with thyroid carcinoma were randomized to the MHI group or the control group. All patients received total thyroidectomy and bilateral central compartment lymph node dissection. The primary outcomes were the PG resection rate and lymph node staining rate. The full analysis set (FAS) included 461 patients, of which 228 were assigned to the MHI group, and 233 were assigned to the control group. The PG resection rates of the MHI group and the control group were 6.6% (15/228) and 26.6% (62/233), respectively, with a significant difference (P < 0.001). No PGs were stained blue with MHI. The central lymph nodes were stained blue with MHI, and the staining rate was 90.5%±12.0%. More lymph nodes were detected in the MHI group than in the control group (13.0±7.3 vs. 10.1±6.4 nodes/patient, P < 0.001). No adverse events related to MHI were observed. MHI is a safe and effective tracer that may help to preserve PGs and identify more central lymph nodes in patients with thyroid cancer.

Superiority of metastatic lymph node ratio over number of node metastases and TNM/AJCC N classification in predicting cancer-specific survival in medullary thyroid cancer

BACKGROUND

In medullary thyroid cancer (MTC), it is unclear which nodal classification system, metastatic lymph node ratio (MLNR), number of node metastases, or TNM/AJCC N classification, predicts cancer-specific survival best.

METHODS

Kaplan-Maier analysis of cancer-specific survival after operation at a tertiary center.

RESULTS

Included were 505 MTC patients. The spread of the survival curves was greatest after stratification by MLNR (in 0.20 increments), followed by number of node metastases (in 10-node and 20-node increments) and TNM/AJCC classification (N0, N1a, N1b). After collapsing overlapping survival curves, all adjacent curves (MLNRs ≤0.20 vs. 0.21-0.60 vs. >0.60; 0 vs. 1-20 vs. >20 node metastases; and TNM/AJCC N classification N0/N1a vs. N1b) significantly differed between each other.

CONCLUSIONS

In MTC, MLNR, reflecting intensity of lymphatic spread, predicts cancer-specific survival better than number of node metastases or TNM/AJCC N classification. The applicability of these findings to patients with limited neck dissection requires more research.

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.

Predictive role of intraoperative clinicopathological features of the central compartment in estimating lymph nodes metastasis status

Background

To explore the feasibility of immediate assessment, which focuses on clinicopathological characteristics of central lymph nodes (LNs) during operation. Moreover, to analyze the predictive effect of various evaluated indicators on the nature, quantities, and ratios of central lymph node metastasis (LNM) in papillary thyroid carcinoma (PTC), to provide the basis for precise individualized central lymph node dissection (LND).

Methods

According to the inclusion and exclusion criteria, 1,271 PTC patients were selected in this cohort study. In the study, the clinical and pathological characteristics of the central LNs were evaluated by the treatment groups during the operation, which had a similar therapeutic experience. The parameters including the texture, volume, maximum/vertical meridian, extracapsular infiltration, adhesion or fusion, and nano-carbon staining status of the central LNs were collected. According to the pathological results after the operation, the nature, quantities, and rate of LNM in the central compartment were counted. The relationship between these parameters and metastatic nature, quantities, and ratios was analyzed and compared.

Results

Univariate analysis showed that when the larger size of LNs (especially the maximum meridian >0.9 cm), extracapsular infiltration, adhesion and fusion being found, A higher possibility of LNM in the central compartment (P<0.05), higher number and ratio of metastasis (P<0.05) might be existed. Moreover, more than two positive LNs were more likely to appear. Maximum/vertical meridian <2 and texture hardness could not indicate metastasis (P>0.05) and higher metastasis ratio (P>0.05), but could only be used as a reference for the existence of metastasis (P<0.05). The number of metastatic LNs dissected by carbon nanoparticles during operation could be increased (P<0.05). However, it has no predictive effect on the nature and rate of LNM (P>0.05). Multivariate analysis showed that larger central LNs, the maximum meridian >0.9 cm, extracapsular infiltration, adhesion, and fusion were independent prognostic factors for central LNM (P<0.05), which could be used as a predictor of the properties of central LNs during operation. At the same time, larger LNs, extracapsular infiltration, adhesion and fusion, and nano-carbon black staining were independent predictors of LNM in the central compartment, which are more than two (P<0.05).

Conclusions

It is practical and feasible to evaluate the clinicopathological features of central LNs immediately during the operation. Intraoperative assessment of central LNs volume, capsular infiltration, maximum/vertical meridian, carbon nano tracking, and adhesion and fusion has predictive effects differently on the nature, quantities, and ratios of central LNM. In order to make an early prediction and advance judgment, surgeons should pay more attention to evaluate clinicopathological features of central LNs during operation, which is conducive to the proper implementation of LND in the central compartment.