Functional recovery after tongue cancer surgery involves restoration of oral intake, speech intelligibility, and swallowing function. The Functional Oral Intake Scale (FOIS) is a simple, validated tool for grading oral intake, while the Performance Status Scale–Head and Neck (PSS-HN) measures patient-reported functional outcomes. Their relationship in postoperative tongue cancer patients is not well defined.

A retrospective analysis was conducted on postoperative tongue cancer patients with documented FOIS and PSS-HN scores. Correlations between FOIS and PSS-HN subscales—Speech Understandability, Eating in Public, and Normalcy of Diet—were assessed using Spearman’s correlation coefficient. Missing data were handled using multiple imputation prior to analysis.

A total of 100 patients were included. Higher FOIS scores were significantly associated with improved functional outcomes. FOIS showed a moderate correlation with Speech Understandability (ρ = 0.62, p < 0.001), a strong correlation with Eating in Public (ρ = 0.74, p < 0.001), and the strongest correlation with Normalcy of Diet (ρ = 0.82, p < 0.001).

FOIS is a robust marker of postoperative functional recovery in tongue cancer patients and correlates strongly with patient-reported speech and swallowing outcomes.