Aims: Oral tongue squamous cell carcinoma (OTSCC) has a relatively poor outcome, and there is a need to identify better prognostic factors. Recently, tumour–stroma ratio (TSR) has been associated with prognosis in several cancers. The aim of this multi‐institutional study was to evaluate the prognostic value of TSR from original haematoxylin and eosin (HE)‐stained tumour‐resection slides in a series of early‐stage (cT1‐2N0) OTSCC patients.

Methods and results: A TSR cutoff value of 50% was used to divide the patients into stroma‐rich (≥50%) and stroma‐poor (<50%) groups. The relationships between TSR and clinicopathological characteristics of 311 early‐stage OTSCC cases were analysed. The prognostic value of TSR in OTSCC was calculated separately and in combination with a previously published cancer cell budding and depth of invasion (BD) prognostic model. A total of 89 cases (28.6%) belonged to the stroma‐rich group. In a multivariate analysis, the stroma‐rich group had worse disease‐free survival, with a hazard ratio (HR) of 1.81 [95% confidence interval (CI) 1.17–2.79, P = 0.008], and higher cancer‐related mortality (HR 1.71, 95% CI 1.02–2.86, P = 0.03). The combination of the highest‐risk parameter scores of TSR and the BD model showed significant correlations with recurrence rate (HR 3.42, 95% CI 1.71–6.82, P = 0.004) and cancer‐related mortality (HR 11.63, 95% CI 3.83–35.31, P < 0.001).

Conclusions: We conclude that TSR is a simple histopathological feature that is useful for prognostication of early‐stage OTSCC, and suggest that TSR analyses in association with BD score could be included in routine clinical pathology reports for HE‐stained slides.