From Nodal Metastasis to Oncologic Recurrence in Tongue and Oral Floor Squamous Cell Carcinoma: Distinct Failure...

Locoregional recurrence remains a clinically relevant problem in oral squamous cell carcinoma (OSCC). Whether local, ipsilateral nodal, and contralateral nodal failure represent distinct disease processes with different clinicopathological associations has not been systematically evaluated.

This retrospective single-center study included patients only with primary OSCC of the tongue or floor of mouth undergoing surgical resection and neck dissection (2011-2021; n = 438). Oncologic recurrence patterns were evaluated in patients with at least six months of follow-up (n = 363) using multivariable Cox regression adjusted for adjuvant therapy and Kaplan-Meier analyses.

Nodal involvement at primary surgery was associated with depth of invasion, bone infiltration, and posterior tongue subsites. In the follow-up cohort, 120 patients (33.1%) developed recurrence. Local recurrence (18.5%) was independently associated with extranodal extension (HR 1.88, 95% CI 1.04-3.40; p = 0.037). Ipsilateral nodal recurrence (11.0%) was associated with lymph node ratio (LNR) > 0.1 versus LNR = 0 (HR 4.90, 95% CI 1.76-13.63; p = 0.002). Contralateral nodal recurrence (8.5%) was not predicted by any evaluated parameter. Patients with LNR > 0.1 experienced recurrence after a median of 19.2 versus 103.0-112.4 months (p < 0.001).

Local and ipsilateral recurrences showed distinct associations with clinicopathological factors, while contralateral recurrence remained poorly predicted by routine parameters. Lymph node ratio was associated with ipsilateral recurrence risk and shorter event-free survival, supporting its use as a potential stratification marker for risk-adapted surveillance.