Seropositivity for human papillomavirus and incidence of subsequent squamous cell and basal cell carcinomas of the skin in patients with a previous nonmelanoma skin cancer

Background Infection with human papillomaviruses (HPVs) is a risk factor for several epithelial cancers, but its relationship with keratinocyte tumours has not yet been established. Objective In this prospective study we investigated the possible role of different HPVs in the incidence of a subsequent nonmelanoma skin cancer (NMSC). Methods One hundred and fifty-three patients with squamous cell carcinoma (SCC) and basal cell carcinoma (BCC) enrolled in a previous case-control study were re-contacted, and a follow-up visit was offered. Demographic and clinical data, date of first NMSC presentation, Fitzpatrick skin type and history of NMSC during the follow-up period were ascertained. Recurrences and new second cancers were considered together as 'outcomes' in time-to-event analyses and in Cox proportional hazard models. Results Clinical data were obtained in 107 patients. HPV seropositivity at baseline was strongly associated with the risk of developing a second SCC after 5 years for a number of beta and gamma HPV types. For example, HPV-24-seropositive patients with an SCC at baseline had a 4-fold increased risk of developing a subsequent SCC (hazard ratio 4.35, 95% confidence interval 1.2-15.6, P = 0.024). No association between serological status for any HPV type tested and an increased risk of BCC was found. Conclusions We observed a consistent pattern of a positive association between seropositivity for beta and gamma HPV types and the risk of a subsequent SCC in patients with a previous SCC. Our data corroborate the results of previous case-control studies and may spur further prospective studies on the causal role of HPVs in NMSC.