Weighted lymph node ratio: New tool in the assessment of postoperative staging of the neck dissection in HPV-negative head and neck squamous cell carcinoma patients

Lymph node ratio (LNR) and lymph node yield (LNY) in head and neck cancer: A systematic review and meta-analysis

INTRODUCTION

A growing amount of evidence points at lymph node yield (LNY) and lymph node ratio (LNR) as useful indicators in the prognostic evaluation of patients affected by head and neck squamous cell carcinoma (HNSCC) who require neck dissection. The aim of this study was to assess the importance of LNY and LNR in the prognostic evaluation of head and neck cancer patients.

MATERIALS AND METHODS

Included studies were those examining LNY and/or LNR in head and neck cancer patients. We excluded case reports or case series, thyroid cancer or salivary gland cancer studies, a sample size less than 20, and studies with incomplete or missing survival estimate. Of the 2435 studies identified through a database search, 95 were reviewed for full text and 63 were finally included for the final analysis. Electronic databases, including PubMed (MEDLINE), Embase, and Scopus were screened up to January 1, 2024. The systematic review was conducted according to the MOOSE checklist. A set of sub-group meta-analyses were performed for oral cavity, oropharynx, hypopharynx, larynx, and mixed subsites using a random-effects model. Overall survival (OS), Disease Specific Survival (DSS), and Disease-Free Survival (DFS) Hazard Ratios (HR) related to a prespecified LNR and LNY exact value were chosen as summary statistics. Cumulative Hazard Ratios with 95% Confidence Interval (CI) were presented, calculated through the inverse variance method. Heterogeneity was evaluated with I2 statistics.

RESULTS

Results of the meta-analysis showed increased OS for a higher LNY (HR 1.33 95% CI 1.23-1.45). Regarding the LNR, a lower LNR value has an impact on survival, with an OS HR of 1.96 (95% CI 1.72-2.24). The same was true for DFS (HR 2.43 95% CI 1.82-3.23), and DSS (HR 2.07 95% CI 1.83-2.33).

CONCLUSIONS

Our analysis confirms the importance of LNY and LNR as prognostic indicators. Future studies are needed to establish the optimal cut-off values for both factors. LNY and LNR have the potential to be routinely evaluated in patients who undergo neck dissection for HNSCC.

The inflammatory markers and locoregional pathological results both have an impact on the prognosis of oral squamous cell carcinoma in patients who have undergone neck dissection

BACKGROUND

Locoregional surgical pathology, with surgical margins at the primary site and lymph node (LN) metastasis, particularly extranodal extension (ENE), plays an important role in the prognosis of oral squamous cell carcinoma (OSCC). In addition, systemic inflammatory response and nutritional status are associated with poor prognosis.

PURPOSE

This study aimed to comprehensively assess the effect of inflammatory markers and locoregional factors on the prognosis of patients with OSCC who underwent neck dissection (ND).

METHODS

This retrospective cohort study included patients who had undergone ND for OSCC between 2013 and 2021. The primary predictive variables were the weighted lymph node ratio (WLNR) and inflammatory markers. Primary outcome variables were overall survival (OS) and disease-free survival (DFS).

RESULTS

Among 153 patients (99 males, 54 females), 55 (35.9 %) had LN metastasis and 11 (7.2 %) exhibited ENE. The inflammatory markers lymphocyte/monocyte ratio (LMR), monocyte/albumin ratio (MAR), C-reactive protein/albumin ratio (CAR), and WLNR demonstrated significant cut-off values for survival, with values of 4.805, 104.72, 0.041, and 0.0235, respectively. The Cox proportional hazards model revealed significant differences in age, WLNR, LMR, MAR, CAR, and vascular, lymphatic, and perineural invasion (Pn). Multivariate analysis indicated that the hazard ratios (95 % confidence intervals) for WLNR (3.416; 1.542-7.566), MAR (2.404; 1.254-4.607), and Pn (2.516; 1.291-4.905) were independent variables for OS.

CONCLUSIONS

In patients with OSCC who underwent ND, the inflammatory marker MAR and locoregional factors WLNR and Pn were simultaneously identified as prognostic factors.

Assessing Prognostic Value of Quantitative Neck Dissection Quality Measures in Patients With Clinically Node-Negative Oral Cavity Squamous Cell Carcinoma

Importance

In clinically localized (T1-2) oral cavity squamous cell carcinoma (OCSCC), regional lymph node metastasis is associated with a poor prognosis. Given the high propensity of subclinical nodal disease in these patients, upfront elective neck dissections (END) for patients with clinically node-negative disease are common and associated with better outcomes. Unfortunately, even with this risk-adverse treatment paradigm, disease recurrence still occurs, and our understanding of the factors that modulate this risk and alter survival have yet to be fully elucidated.

Objective

To investigate the prognostic value of lymph node yield (LNY), lymph node ratio (LNR), and weighted LNR (wLNR) in patients with clinically node-negative T1-2 OCSCC.

Design, Setting, and Participants

In this cohort study, data were collected retrospectively from 7 tertiary care academic medical centers. Overall, 523 patients with cT1-2N0 OCSCC who underwent elective neck dissections after primary surgical extirpation were identified.

Exposures

Lymph node yield was defined as the number of lymph nodes recovered from elective neck dissection. Lymph node ratio was defined as the ratio of positive nodes against total LNY. Weighted LNR incorporated information from both LNY and LNR into a single continuous metric.

Main Outcomes and Measures

Locoregional control (LRC) and disease-free survival (DFS) were both evaluated using nonparametric Kaplan-Meier estimators and semiparametric Cox regression.

Results

On multivariable analysis, LNY less than or equal to 18 lymph nodes was found to be significantly associated with decreased LRC (aHR, 1.53; 95% CI, 1.04-2.24) and DFS (aHR, 1.46; 95% CI, 1.12-1.92) in patients with pN0 disease, but not those with pN-positive disease. Importantly, patients with pN0 disease with LNY less than or equal to 18 and those with pN1 diseasehad nearly identical 5-year LRC (69.7% vs 71.4%) and DFS (58.2% vs 55.7%). For patients with pN-positive disease, LNR greater than 0.06 was significantly associated with decreased LRC (aHR, 2.66; 95% CI, 1.28-5.55) and DFS (aHR, 1.65; 95% CI, 1.07-2.53). Overall, wLNR was a robust prognostic variable across all patients with cN0 disease, regardless of pathologic nodal status. Risk stratification via wLNR thresholds demonstrated greater optimism-corrected concordance compared with American Joint Committee on Cancer (AJCC) 8th edition nodal staging for both LRC (0.61 vs 0.57) and DFS (0.61 vs 0.58).

Conclusions and Relevance

Movement toward more robust metrics that incorporate quantitative measures of neck dissection quality and regional disease burden, such as wLNR, could greatly augment prognostication in cT1-2N0 OCSCC by providing more reliable and accurate risk estimations.

Is the addition of extranodal extension and lymph node yield of pN0 to the lymph node ratio useful as a prognostic parameter for patients with oral squamous cell carcinoma?

We investigated the value of the weighted lymph node ratio (WLNR), a new marker in pN0 patients that incorporates the number of metastatic lymph nodes with extranodal extension and the lymph node yield, for the prognosis and postsurgical management of oral squamous cell carcinoma (OSCC). We designed a retrospective study and enrolled patients with OSCC who were treated by neck dissection (ND). The predictor variable was WLNR, and the outcome variable was overall survival (OS). The Cox proportional-hazards model was used to identify independent prognostic factors. In 133 patients with OSCC, the WLNR cut-off value for predicting OS was 0.0363 (area under the curve 0.723, p<0.001). When stratified according to WLNR, there was a significant difference in OS (88.4% for low WLNR and 63.0% for high WLNR, p<0.001). Univariate analyses showed close associations between OS and age, dissection area, postoperative management, extranodal extension, number of positive lymph nodes, pN stage, WLNR, and nodal disease area. Cox multivariate analysis identified the WLNR as an independent predictive factor for OS (HR 3.273, 95% CI 1.227 to 8.731, p=0.018). As a predictive factor, a high WLNR (≥0.0363) in patients with pN0 disease, which included the addition of extranodal extension and lymph node yield to the LNR, was associated with diminished survival.

Current status of systemic therapy in head and neck cancer

There are several controversies in the management of head and neck cancer (SCCHN). Although combined modality treatment is standard in locally advanced SCCHN (LA-SCCHN), the optimal timing of chemotherapy has been debated. Toxicity concerns with chemoradiation (CRT) using high dose cisplatin have prompted use of less intensive approaches. Weekly cisplatin and targeted therapies have been explored in randomized trials. Benefit of neoadjuvant chemotherapy in LA-SCCHN is debated due to lack of impact on overall survival, however, it remains a viable option in the Indian setting where many patients are not eligible for upfront surgery or definite CRT due to advanced stage and poor performance status (PS). The complexity of data of immune check point inhibitors (ICPi) in metastatic setting needs cautious interpretation till an ideal biomarker for their benefit is identified. Their significant cost and promising data of oral metronomic therapy has made the treatment landscape of metastatic SCCHN even more complex. To address these burning issues, we did a critical review of evidence of systemic therapy in SCCHN.

Radiomic Model Predicts Lymph Node Response to Induction Chemotherapy in Locally Advanced Head and Neck Cancer

This study developed a pretreatment CT-based radiomic model of lymph node response to induction chemotherapy in locally advanced head and neck squamous cell carcinoma (HNSCC) patients. This was a single-center retrospective study of patients with locally advanced HPV+ HNSCC. Forty-one enlarged lymph nodes were found from 27 patients on pretreatment CT and were split into 3:1 training and testing cohorts. Ninety-three radiomic features were extracted. A radiomic model and a combined radiomic-clinical model predicting lymph node response to induction chemotherapy were developed using multivariable logistic regression. Median age was 57 years old, and 93% of patients were male. Post-treatment evaluation was 32 days after treatment, with a median reduction in lymph node volume of 66%. A three-feature radiomic model (minimum, skewness, and low gray level run emphasis) and a combined radiomic-clinical model were developed. The combined model performed the best, with AUC = 0.85 on the training cohort and AUC = 0.75 on the testing cohort. A pretreatment CT-based lymph node radiomic signature combined with clinical parameters was able to predict nodal response to induction chemotherapy for patients with locally advanced HNSCC.

Prognostic capacity of the weighted lymph node ratio in head and neck squamous cell carcinoma patients treated with salvage neck dissection

PURPOSE

The aim of the study was to assess the prognostic capacity of the recently described weighted lymph node ratio (WLNR) in patients with head and neck squamous cell carcinoma (HNSCC) who undergo salvage neck dissection for regional recurrence.

MATERIAL AND METHODS

We retrospectively studied 197 adult patients with head and neck squamous cell carcinoma treated with salvage neck dissection from 1990 to 2017.

RESULTS

The mean value for the WLNR for all patients was 26.2%. We established a classification based on the WLNR values taking 10.8% as the cut-off point. Five-year disease-specific survival for patients with WLNR ≤ 10.8% (n = 89, 45.2%) was 39.9% (IC 95% 29.4-50.4%), and for patients with WLNR ≥ 10.8% (n = 108, 54.8%) it was 20.5% (IC 95% 12.3-28.7%) (p = 0.007). The multivariate analysis showed the WLNR had a significant prognostic capacity.

CONCLUSIONS

As a variable that integrates data related to the number of metastatic nodes with extracapsular spread to the LNR, the WLNR has a prognostic value in the pathological assessment of HNSCC patients with regional recurrence treated with salvage neck dissection.