Evidence for the association of human papillomavirus infection and cutaneous squamous cell carcinoma in immunocompetent individuals

Objective: The aim of our study was to evaluate human papillomavirus (HPV) infection as a risk factor for cutaneous squamous cell carcinoma (SCC) in immunocompetent individuals. Design: Hospital-based case-control study. Setting: Referral center for dermatologic diseases for central and southern Italy. Participants: Consecutive patients with histologically confirmed cutaneous SCC (n = 46) and control subjects (n = 84) chosen by frequency matching (age and sex) among patients admitted with unrelated diseases. Main Outcome Measure: Infection with epidermodysplasia verruciformis-related HPV types, blindly assessed by serologic testing (viruslike particle enzyme-linked immunosorbent assay). Information was obtained on known potentially confounding risk factors (family history, history and signs of sun exposure, and pigmentary traits) and on history of HPV-related lesions and diseases, assessed by inter-view and examination by a dermatologist. Results: Positive serologic findings for HPV type 8 were associated with SCC (odds ratio, 3.2; 95% confidence interval, 1.3-7.9) independently of other risk factors, whereas positive serologic findings for HPV type 15 were negatively associated with SCC (odds ratio, 0.4; 95% confidence interval, 0.2-0.9). Other variables significantly associated with the tumor were family history of skin cancer, professional or recreational sun exposure, light eye color, high number of solar keratoses and seborrheic keratoses on the body surface, and residency in radon-emitting buildings. Conclusions: Positive serologic findings for HPV type 8 are associated with SCC occurrence in immunocompetent individuals. Viral infection could act as a cofactor in the tumor development, along with genetic predisposition, solar radiation, and other environmental exposures. if confirmed, these findings could open new perspectives for treatment and prevention of SCC.