Human Papillomaviruses in transplant-associated skin cancers

BACKGROUND. Human papillomavirus (HPV) infection has been suggested to be involved in the development of nonmelanoma skin cancer, the Most common malignancy after solid-organ transplantation. OBJECTIVE. The objective of this study was to analyze the prevalence of different HPV types in squamous cell carcinomas (SCC) and basal cell carcinomas (BCC) of transplant recipients and nonimmunosuppressed patients. METHODS. To include the complete spectrum of HPV types in skin lesions, a comprehensive polymerase chain reaction assay with five different primer combinations was used. RESULTS. For SCC, HPV DNA was detected more frequently in tumors of transplant recipients (12/16, 75%) than of nonsuppressed patients (7/19, 37%). In contrast, the HPV detection rate was similar in BCC specimens (4/8 or 50% in transplanted patients; 27/56 or 48% in nonimmunosupressed patients). Overall, 22 different HPV types were identified. HPV types 5 and 8 were detected predominately in SCC from transplant recipients. The amount of viral DNA was slightly higher in SCC of transplanted than in nonimmunosuppressed patients, but much lower than in both cutaneous and genital warts. CONCLUSIONS. Cutaneous infections with HPV5 and HPV8 may represent an increased risk for SCC development in transplant recipients. The mechanisms by which these viruses may contribute to skin cancer development still remain unclear.