In Vivo Probability of Metastases in Levels IV-V in Oral Squamous Cell Carcinoma With a cN0/pN+ Situation in Levels I-III

Abstract

Background/Aim: The optimal extent of neck dissection (ND) in oral squamous cell carcinoma (OSCC) is controversial, particularly regarding levels IV and V in cases with metastases in levels I-III. This study evaluated the probability of metastases in levels IV-V when levels I-III are pN+ in cN0 necks and analyzes prognostic factors influencing their occurrence. Patients and Methods: A retrospective study was performed at the Department of Oral, Maxillofacial and Facial Plastic Surgery, Ludwigshafen Hospital, Germany, including 61 patients with primary OSCC treated surgically including ND. Patients underwent either supraomohyoid ND (SOND) of levels I-III with secondary extension to IV-V or modified radical ND (MRND) of levels I-V. Statistical analysis assessed the correlation between metastases in levels IV-V and extracapsular spread (ECS), number of positive lymph nodes, T-classification, bone infiltration, grading, lymphovascular invasion, vascular invasion, and perineural invasion. Results: Among the 61 patients with metastases in levels I-III, 6 patients (9.8%) had metastases in levels IV-V. A significant correlation (p=0.042) indicated that pN+ in levels I-III is associated with >5% risk of level IV-V metastases. The presence of more than one metastasis in levels I-III significantly (p=0.027) predicted level IV-V involvement. A pN status of >pN2b significantly (p=0.002) increased the prevalence of metastases in levels IV-V. ECS showed a trend toward increased IV-V involvement, though not statistically significant (p=0.078). Conclusion: The risk of level IV-V metastases in patients with pN+ in levels I-III exceeds 5% in cN0 necks. The number of affected nodes and pN classification were the strongest predictors. These findings support selective extension of ND beyond level III in specific patients and emphasize individualized treatment strategies.