CT-to-surgery interval and occult nodal metastasis in cN0 oral squamous cell carcinoma

CT-based staging of the clinically node-negative (cN0) neck in oral squamous cell carcinoma (OSCC) has limited sensitivity, and occult nodal metastasis remains common. Whether the CT-to-surgery interval influences pathological nodal outcome is unclear.

This retrospective study included 329 patients with primary cN0 OSCC undergoing CT staging and neck dissection (2011-2024). Associations with lymph node positivity, lymph node count, and extranodal extension (ENE) were assessed using logistic and negative binomial regression, with sensitivity analyses (quartiles, exclusion of extreme intervals, lymph node yield adjustment).

Median CT-to-surgery interval was 9.0 days (IQR 5.0-15.0), and 53 patients (16.1%) had lymph node metastasis. The interval was associated with lymph node positivity in univariable analysis (OR 1.031, p = 0.035), but not after adjustment for age and smoking (OR 1.027, p = 0.065); lymph node count showed a similar non-significant association (IRR 1.027, p = 0.068). The association with nodal positivity was not robust across interval quartiles (p = 0.969), after excluding intervals >30 days (OR 0.995, p = 0.824), or after adjustment for lymph node yield (OR 1.015, p = 0.334). However, patients with intervals >30 days (n = 13) had higher nodal positivity than those with shorter intervals (53.8% vs. 14.6%). The interval was not associated with ENE (p = 0.740), and tumor localization was not associated with nodal positivity (p = 0.175).

An initially significant, unadjusted association was not robust to sensitivity testing and was confined to a small subgroup with substantially prolonged intervals. This offers some reassurance that the CT-to-surgery interval is not strongly associated with occult nodal metastasis in cN0 OSCC, while substantially delayed surgery warrants further investigation.