Abstract / Summary
Oral and pharyngeal cancers are major contributors to global cancer-related morbidity and mortality, particularly in regions with high prevalence of tobacco, alcohol, and chewing-related exposures. Caffeine-containing beverages such as coffee and tea may influence carcinogenesis through antioxidant, anti-inflammatory, and antiproliferative effects. This review evaluated the association between coffee consumption and the risk of oral and pharyngeal cancer. A systematic search of PubMed/MEDLINE, Scopus, Web of Science, Cochrane Library, and Google Scholar was conducted from inception to March 2026. Observational studies assessing coffee consumption and oral and/or pharyngeal cancer risk were included. Pooled effect estimates were calculated using a random-effects inverse-variance model with DerSimonian–Laird estimation. Subgroup analyses were performed by geographical region, study design, and cancer site. Publication bias was assessed using Egger’s test. Twenty studies were included. Higher coffee consumption was associated with significantly lower risk of oral and pharyngeal cancer (pooled estimate: 0.57; 95% CI: 0.49–0.66). Moderate heterogeneity was observed (I²=46.0%). The inverse association remained consistent across regions, study designs, and cancer subgroups. Egger’s test showed no significant small-study effects ( p = 0.166), and sensitivity analysis confirmed the stability of results. Higher coffee consumption is associated with reduced risk of oral and pharyngeal cancer. However, causal inference is limited by the observational nature of included studies and variability in exposure assessment. Not Applicable.