Factors Associated with Lymph Node Count in Mucosal Squamous Cell Carcinoma Neck Dissection

Nodal Yield From Neck Dissection Predicts the Anti-Tumor Immune Response in Head and Neck Cancers

BACKGROUND

Lymph node count (LNC) from neck dissection has been associated with undernutrition and survival in head and neck squamous cell carcinoma (HNSCC). As local components of the immune system, cervical lymph nodes may reflect anti-tumor immune status. This study investigates the relationship between decreased LNC, formation of tertiary lymphoid structures (TLS), and primary tumor infiltration by lymphocytes in undernourished patients.

METHODS

A matched-cohort study was conducted in a tertiary medical center, where neck dissection quality was standardized for a total of 384 subjects that were evaluated. Six head and neck cancer patients that underwent primary surgery including neck dissection with low LNC and BMI (low BMI < 23, low LNC ≤ 5.6 per neck level) were matched by stage, p16 status, and subsite to 16 patients with normal BMI and high LNC. Multiplexed immunohistochemistry was used to evaluate the tumor-infiltrating lymphocytes and the number and quality of TLS within primary tumors. Whole primary cancers underwent automated analysis and counting of leukocytes after multiplexed immunohistochemistry staining of tumor slides. A head and neck pathologist blindly scored the number and maturity of TLS. Descriptive statistics were used to analyze outcomes.

RESULTS

The patients with low BMI and low LNC had significantly fewer CD3 (p = 0.0136), CD8 (p = 0.0003), and CD20 (p = 0.0334) cells in their primary tumors compared to patients with normal BMI and LNC. The low BMI low LNC patients also had fewer mature TLS (0.83/tumor) in their primary cancers compared to patients with normal BMI and high LNC (5.4/tumor) and also had greater than fourfold lower mature TLS density (TLS per μm2 mean) (6.34 × 10-9 vs. 2.82 × 10-8), with significantly worsened survival relative to patients with low BMI and normal LNC and patients with normal BMI.

CONCLUSION

Low LNC predicts worsened survival only in low BMI HNSCC patients with non-HPV related tumors and in these patients is associated with markers of immunosuppression such as fewer tumor-infiltrating CD8+ T-cells, CD20+ cells, and fewer TLS in primary cancers compared to matched normal BMI patients with high LNC.

Factors influencing lymph node yield in head and neck squamous cell carcinoma: A scoping review

OBJECTIVES

In head and neck cancer surgery, several studies have demonstrated the prognostic significance of lymph node yield (LNY). To our knowledge, no review has evaluated both the contributing factors to LNY and its impact on survival outcomes across all head and neck squamous cell carcinoma (HNSCC) subsites.

MATERIALS AND METHODS

A scoping review of LNY in HNSCC was conducted according to The Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for Scoping Reviews (PRISMA-ScR) framework to answer the following research questions: 1) Which surgeon, pathologist, and patient characteristics influence LNY? 2) Which anatomic subsites does LNY impact survival?

RESULTS

Surgeon experience and variation in pathology protocols and personnel can impact LNY. Extent of nodal dissection, advanced tumor characteristics, and treatment at an academic facility are associated with increased LNY. Patient characteristics such as age <40, male gender, and BMI > 30 are associated with increased LNY. In the oral cavity, LNY > 18 is an independent predictor of improved overall survival (OS), disease free survival (DFS), and disease-specific survival (DSS). In the oropharynx, published studies show mixed results with regards to the impact of LNY on OS, DFS, and DSS. LNY has not been associated with OS or DFS in the larynx, irrespective of nodal threshold.

CONCLUSIONS

Provider and patient characteristics may impact LNY. LNY ≥ 18 is associated with a survival benefit in the oral cavity and HNSCC overall. Further investigation of LNY particularly in prospective clinical trials is required prior to its adoption as a quality metric in HNSCC.

Nodal Yield in Level II-IV Neck Dissections in Head and Neck Squamous Cell Carcinoma

OBJECTIVES

The main objective of this study is to analyze factors associated with nodal yield in level II-IV selective neck dissections (NDs) and the secondary objective is to assess its impact on overall and disease-free survival.

METHODS

Observational retrospective study including adult patients submitted to level II-IV ND from January 2015 to December 2021 in the otorhinolaryngology department of a tertiary hospital center.

RESULTS

A total of 44 patients and 78 level II-IV NDs (34 bilateral and 10 unilateral) were included. The median age at diagnosis was 60 (22-74) years, and 93.2% of the patients were male. A lower nodal yield was significantly associated with previous radiotherapy (p = 0.042) and extranodal invasion (p < 0.001) and was non-significantly associated with older age (p = 0.065). Furthermore, on a Cox analysis adjusted to the cN status and age, the nodal yield was not associated with five-year disease-free survival (HR = 0.986; 95% CI = 0.922-1.054; p = 0.681) nor with five-year overall survival (HR = 1.006; 95% CI = 0.925-1.095; p = 0.888).

CONCLUSION

A reduced nodal yield in level II-IV NDs was significantly associated with previous radiotherapy and extranodal extension and non-significantly associated with age. There was no association between the nodal yield and five-year overall survival or disease-free survival.

Node Count as a Quality Indicator in Surgically Treated Mucosal Head and Neck Squamous Cell Cancer

INTRODUCTION

A yield of ≥18 nodes from neck dissection has been shown to be associated with improved locoregional recurrence rates and survival. We sought to determine factors associated with lymph node yields below this threshold.

MATERIALS AND METHODS

A retrospective review of patients who underwent neck dissection as part of definitive surgical treatment for mucosal head and neck squamous cell carcinoma (SCC) between January 2015 and December 2018 at an academic tertiary referral center was performed. Patients with a history of prior radiation or neck dissection were excluded.

RESULTS

There were 412 neck dissections performed in 323 patients. Specimens containing <18 nodes decreased from 16.2% in 2015-2016 to 7.4% of neck dissections in 2017-2018. The proportion of neck dissections removing <3 levels decreased from 9.1% of neck dissections in 2015-2016 to 4.0% in 2017-2018. Multivariable regression analysis demonstrated that dissection of ≥3 levels (OR = 0.2 [0.1-0.4]) and neck dissection in 2017-2018 compared to 2015-2016 (OR = 0.4 [0.2-0.8]) were significantly associated with a lower odds of <18 nodes. Stage, site, race, sex, human papillomavirus status, positive nodes, surgeon volume, and pathologist volume were not associated with neck dissection specimens with <18 nodes, after controlling for all other variables.

CONCLUSIONS

Increased recognition of the importance of node count as a quality indicator, and the extent of neck dissection is associated with increased nodal yield from neck dissection. These data suggest that node count can be used as a quality measure of neck dissection for mucosal SCC.

LEVEL OF EVIDENCE

4 Laryngoscope, 133:2160-2165, 2023.