Trends in Stage and Age at Diagnosis of Oral Squamous Cell Carcinoma Over Time: A Systematic Review and Meta-Analysis

To evaluate whether the age at diagnosis of oral squamous cell carcinoma (OSCC) has changed over time and to assess whether stage at presentation has varied across decades.

A systematic review was conducted according to PRISMA guidelines (PROSPERO registration: CRD420251048070). MEDLINE, Scopus, and Web of Science were searched. Studies reporting age at diagnosis and/or stage distribution of OSCC were included.

Twenty-nine studies (15,911 subjects) were included. A primary meta-analysis of 11 eligible studies (n = 3527) yielded a pooled mean age at diagnosis of 57.42 years (95% CI: 54.51-60.33). A sensitivity analysis (8 studies with sample size ≥ 100 patients, total = 3322) produced a pooled estimate of 55.61 years (95% CI: 52.32-58.91), suggesting a potentially meaningful shift toward younger age at diagnosis in larger cohorts. Early-stage disease (I-II) accounted for 54.2% of cases and advanced-stage disease (III-IV) for 45.8%. Variability in staging systems (AJCC/UICC editions) and reporting formats limited direct cross-decade comparisons.

Current evidence is compatible with a modest, population-dependent trend toward younger age at diagnosis in selected contemporary cohorts. Standardized staging, harmonized reporting, and age-stratified risk-factor analyses are needed to clarify whether emerging young-onset OSCC reflects changing exposure profiles, distinct tumor biology, or both.

PROSPERO Registration: CRD420251048070.