Neck Dissection and Survival Among Head and Neck Cancer Patients Undergoing Adjuvant Immunotherapy.

BACKGROUND

Some studies suggest that neck dissection (ND) should be avoided in candidates for immunotherapy because lymph nodes are primary sites for immunotherapy activation. Our study investigates ND utilization and associated differences in overall survival (OS) among patients with head and neck cancer (HNC) undergoing adjuvant immunotherapy.

METHODS

The 2013-2018 National Cancer Database was retrospectively reviewed for patients with HNC undergoing surgery with curative intent, and adjuvant immunotherapy. Multivariable binary logistic and Cox regression models adjusted for patient demographics, clinicopathologic features, and treatment.

RESULTS

Of 1335 patients satisfying inclusion criteria, 679 (50.9%) patients underwent ND: 94 (13.8%) had pN0, 109 (16.1%) had pN1, 411 (60.5%) had pN2, 60 (8.8%) had pN3, and 5 (0.7%) had pNx classification. On multivariable binary logistic regression, academic treatment facility, cT4, and cN1-3 classification were associated with higher odds of undergoing ND (p < 0.05); salivary, sinonasal, oropharyngeal, hypopharyngeal, and laryngeal primary sites were associated with decreased odds (p < 0.05). Compared with those undergoing neck observation, patients undergoing ND had worse OS (49.4% vs. 61.5%, p < 0.001) on Kaplan-Meier but not multivariable Cox (adjusted hazard ratio [aHR] 1.00, 95% confidence interval [CI] 0.82-1.24, p = 0.968) regression. Compared with adjuvant immunotherapy alone, the addition of radiotherapy (aHR 0.64, 95% CI 0.44-0.93) and chemoradiotherapy (aHR 0.56, 95% CI 0.37-0.86) were associated with higher OS (p < 0.025).

CONCLUSION

ND was utilized in approximately 51% of patients with HNC undergoing adjuvant immunotherapy. ND was not associated with worse OS, possibly related to the high rate of pN1-3 classification.

LEVEL OF EVIDENCE: 4.