Treatment of Head and Neck Cancer-Sometimes, Less Is More

Microscopic Extranodal Extension in HPV-Negative Head and Neck Cancer and the Role of Adjuvant Chemoradiation

OBJECTIVE

Pathologic extranodal extension (ENE) is an important adverse feature for human papillomavirus (HPV)-negative head and neck squamous cell carcinoma (HNSCC), but the prognostic significance of microscopic ENE (ENEmi) and role of adjuvant concurrent chemoradiation (CRT) for ENEmi remain unclear. This study evaluates (1) the prognostic significance of ENEmi in HPV-negative HNSCC and (2) whether adjuvant CRT is associated with improved overall survival (OS) for these patients.

STUDY DESIGN

Retrospective cohort study.

SETTING

Commission on Cancer (CoC)-accredited facilities.

METHODS

This retrospective cohort study included patients in the National Cancer Database from 2009 to 2015 with pathologic node-positive (pN+) HPV-negative HNSCC with either pathologic ENEmi or no ENE who had undergone margin-negative surgery. The association of ENEmi with OS was evaluated using Cox proportional hazard analyses. Analyses were repeated in patients with ENEmi receiving adjuvant therapy to evaluate the association of adjuvant CRT with OS.

RESULTS

We included 5483 patients with pN+ HPV-negative HNSCC, of whom 24% had ENEmi. On multivariable analysis, ENEmi was associated with decreased OS relative to no ENE (adjusted hazard ratio [aHR], 1.43; 95% CI, 1.28-1.59). Among patients with ENEmi who received ≥60 Gy of adjuvant radiation therapy (RT) (n = 617), adjuvant CRT was not associated with improved OS relative to RT (aHR, 0.91; 95% CI, 0.66-1.27).

CONCLUSION

For patients with HPV-negative HNSCC, pN+ with ENEmi is associated with worse OS than pN+ without ENE. However, for patients with ENEmi, concurrent CRT is not associated with improved OS relative to RT. The optimal adjuvant paradigm for ENEmi requires additional investigation.

Evaluating Adjuvant Therapy With Chemoradiation vs Radiation Alone for Patients With HPV-Negative N2a Head and Neck Cancer

Importance

The American Joint Committee on Cancer staging system (Cancer Staging Manual, 8th Edition) for head and neck squamous cell carcinoma (HNSCC) now categorizes human papillomavirus (HPV)-negative HNSCC in a single positive lymph node smaller than 3 cm with pathologic extranodal extension (ENE) as N2a. The standard of care for pathologic ENE is adjuvant chemoradiation therapy (CRT). Whether adding chemotherapy concurrent with adjuvant radiation therapy improves survival in this clinical scenario is unknown.

Objective

To assess whether adjuvant CRT relative to radiation therapy alone is associated with improved survival among patients with pN2a HPV-negative HNSCC with ENE.

Design, Setting, and Participants

This retrospective cohort study included 504 patients with pN2a HPV-negative HNSCC with ENE who had undergone margin-negative surgery and adjuvant therapy. The patients were identified from the National Cancer Database from January 1, 2004, to December 31, 2015. Statistical analyses were conducted from September 1, 2019, to April 16, 2020.

Main Outcomes and Measures

The primary end point was overall survival. The association of adjuvant CRT with overall survival was analyzed using univariate and multivariate Cox proportional hazards regression analyses. Planned subset analyses were conducted in patients younger than 70 years with no comorbidities (the subset most likely to be eligible for a clinical trial of cisplatin-based chemoradiation) and in patients with pT3/T4 disease classification.

Results

Of 504 patients (mean [SD] age, 60.5 [12.7] years; 319 [63.3%] men; 434 [86.1%] White) with pN2a HPV-negative HNSCC with ENE who had undergone margin-negative surgery and adjuvant therapy, 298 patients (59.1%) received adjuvant CRT. For the overall cohort of patients with pN2a ENE, adjuvant CRT was not associated with improved overall survival relative to adjuvant radiation therapy alone in a multivariate analysis (adjusted hazard ratio, 0.98; 95% CI, 0.74-1.30). Adjuvant CRT was still not associated with improved overall survival in a subset analysis of 304 patients younger than 70 years with no comorbidities (adjusted hazard ratio, 0.98; 95% CI, 0.66-1.45) nor in a subset of 220 patients with pT3/T4 disease classification (adjusted hazard ratio, 1.03; 95% CI, 0.70-1.54).

Conclusions and Relevance

This study found that for patients with pN2a HPV-negative HNSCC with ENE who underwent margin-negative surgery and adjuvant therapy, adding chemotherapy concurrent with adjuvant radiation therapy was not associated with improved overall survival. Additional research is necessary to identify the optimal treatment paradigm for this clinical scenario.