Measures of cutaneous human papillomavirus infection in normal tissues as biomarkers of HPV in corresponding nonmelanoma skin cancers

Abstract

Cutaneous human papillomavirus (HPV) may be associated with the development of nonmelanoma skin cancer (NMSC), as suggested by reports of HPV DNA in NMSC tumors. HPV has also been investigated as an NMSC risk factor in epidemiologic studies, although findings vary across studies that used different biomarkers of HPV infection in normal tissues. To identify appropriate biomarkers for use in future epidemiologic studies, we conducted a sampling validation study. NMSC tumor tissue was obtained from 20 patients with pathology-confirmed basal or squamous cell carcinoma of the skin, in addition to several normal tissues, including eyebrow hairs, normal skin swabs obtained using multiple techniques, normal skin punch and shave biopsies, and serum for antibody measurement. Presence of cutaneous HPV DNA in tissues was measured with multiplex PCR using HPV type-specific primers and array primer extension (APEX) for HPV typing. Antibody detection was based on glutathione-S-transferase capture ELISA in combination with fluorescent bead technology. Using HPV DNA in tumor tissues as a gold standard, sensitivity and specificity were calculated for each measure of HPV infection in normal tissues. beta-Papillomavirus DNA was observed in tumor tissues in 60% of patients. The normal skin punch biopsy demonstrated optimal sensitivity (75%) and specificity (75%). Biomarkers obtained using less-invasive techniques demonstrated poor specificity when considered individually, although specificity improved when biomarkers were combined. Based on the current case series, the combinations of antibodies+eyebrow hairs or antibodies+eyebrow hairs+Dacron swabs are the optimal, minimally invasive markers of cutaneous HPV infection for use in epidemiologic studies.