Advancing Education, Research, and Quality of Care for the Head and Neck oncology patient.
Introduction: Managing clinically N0 neck in head and neck cancers, especially oral cavity cancers, is challenging due to varying rates of occult metastasis by tumor site and T-stage. Prophylactic neck dissection is generally recommended if occult metastasis risk exceeds 20%. This NCDB study assesses occult lymph node positivity rates across primary sites in the modern era stratified by clinical T-stages.
Methods: This retrospective NCDB analysis included clinically N0 head and neck cancer patients with squamous cell carcinoma (SCC) at six primary sites: hypopharynx, larynx, nasopharynx, oral cavity, oropharynx, and salivary glands. Only patients with confirmed SCC and recorded nodal pathology results were included. Cases were classified by T1–T4 stages and final pathologic nodal status as a binary, “negative” or “positive”. Occult positivity rates by site and clinical T-stage were analyzed using chi-square tests.
Results: Among 37,297 cases included in this study, 27.64% had occult nodal involvement, varying by site and T-stage. Occult positivity rates were as follows: hypopharynx (29.28%), larynx (18.37%), nasopharynx (34.78%), oropharynx (31.10%), oral cavity (27.01%), and salivary glands (34.69%). Only oropharyngeal (p = 0.043) and oral cavity (p < 0.001) SCC showed significant variation in occult rates by T-stage.
In oral cavity SCC, occult positivity rose from 15.95% in T1 to 30.33% in T2 and remained high in T3 (40.61%) and T4 (31.05%) (p < 0.001).
Conclusion: This study describes occult lymph node metastasis rates in the clinically N0 head and neck SCC in the modern era. Clinical T-stage significantly impacts occult metastasis rates in oropharyngeal and oral cavity SCC. Tailoring treatment by site and clinical T-stage may improve N0 neck management in head and neck cancers.