Plasma Fibrinogen at Recurrence as a Prognostic Blood Biomarker in Oral Cavity Squamous Cell Carcinoma.

Background: Preoperative inflammatory biomarkers, particularly the neutrophil-to-lymphocyte ratio (NLR), are established prognostic markers in oral cavity squamous cell carcinoma (OCSCC), yet their relevance at the biologically distinct timepoint of disease recurrence is unknown. We evaluated blood biomarkers measured at recurrence. Methods: From a retrospective cohort of 168 surgically treated OCSCC patients, 70 (41.7%) developed recurrence (49 local, 21 distant). NLR, lymphocyte-to-monocyte ratio (LMR), platelet-to-lymphocyte ratio (PLR), plasma fibrinogen, albumin and the prognostic nutritional index (PNI) at relapse were analysed against 5-year overall survival; multivariate logistic regression was adjusted for age and recurrence type. Results: Forty-nine of 70 patients (70.0%) died within 5 years. Fibrinogen was higher in deceased patients (median 595 vs. 464 mg/dL; p = 0.007) and was the only biomarker to retain independent significance (OR 1.005 per mg/dL; 95% CI 1.000-1.010; p = 0.038); in contrast, NLR lost significance (p = 0.156). LMR was significant univariately (p = 0.036); PLR, albumin and PNI were not. Conclusions: In this exploratory single-centre cohort, higher plasma fibrinogen at recurrence was independently associated with 5-year mortality, whereas inflammatory ratios were not. These hypothesis-generating findings warrant validation in larger, multicentre cohorts.