Human papillomavirus infection and oral squamous cell carcinoma - a systematic review

INTRODUCTION: The association between uterine cervix and anogenital carcinomas and human papillomavirus, HPV, is well established, however the involvement of this virus in the development of oral squamous cell carcinomas remains controversial. OBJECTIVES: To evaluate the relationship between HPV infection and oral squamous cell carcinomas, and to estimate the incidence of this infection in these patients. METHODS: Four electronic databases were searched to find studies that met the following inclusion criteria: i) performed in humans; ii) were cohort, case-control or cross-sectional; iii) assessed the HPV oncogenic activity by the E6 and E7 mRNA; iv) included primary oral squamous cell carcinomas which; v) diagnosis had been confirmed by biopsy. Information about the country; study period; sample obtainment; sites of oral squamous cell carcinomas; number, gender and age range of the population; the prevalence of HPV infection and subtypes detected; use of tobacco or alcohol and oral sex practice were extracted. The methodological quality of included articles was assessed using 14 criteria. RESULTS: The search strategy retrieved 2129 articles. Assessment of the full text was done for 626 articles, but five were included. The total of participants included was 383, most of them male with mean age between 51.0 and 63.5 years old. Seventeen patients were HPV/mRNA-positive, being the subtypes 16 and 18 detected more frequently. Nine of the HPV/mRNA-positive oral squamous cell carcinomas occurred on the tongue. The quality score average of included articles was five points. CONCLUSIONS: Among the 383 oral squamous cell carcinoma patients included, 17 (4.4%) were HPV/mRNA-positive, nevertheless it was not possible to assess if HPV infection was associated with oral squamous cell carcinomas because none of the studies included was longitudinal and cross-sectional investigations do not have control group.