Prevalence of human papillomavirus in skin tumors from repair deficient xeroderma pigmentosum patients

The predisposition to skin cancers in childhood is the hallmark of xeroderma pigmentosum (XP), a rare autosomal recessive disorder, deficient in DNA repair and hypersensitive to ultraviolet irradiation. Human papillomavirus (HPVs), are common infections of the skin which are often found associated to benign lesions and non-melanoma skin cancers (NMSC), mainly squamous cell carcinomas (SCC) and basal cell carcinomas (BCC). Our study is the first to analyse 40 SCCs, 27 BCCs and nine normal skin biopsies from XP patients for HPV DNA which are found more frequently in SCCs (20/40) than in BCCs (4/27) or normal skin (2/9). The HPV spectrum includes 22 different epidermodysplasia verruciformis (EV) HPV types, which predominate in SCCs (48%) compared to BCCs (15%) and normal skin (22%). Our data, showing an association between EV HPV and SCCs from young XP patients is comparable to that found for NMSC from adult immunosuppressed organ transplant patients and raises the question of the importance of HPV infection in skin carcinogenesis.