Detection of mucosal type human papillomavirus in cutaneous squamous cell carcinoma in Iran

Squamous cell carcinoma (SCC) is the second most common non-melanoma skin cancer. The oncogenic role of human papilloma virus (HPV) in cutaneous SCC has been suggested by several studies performed on immunosuppresed patients. However, the role of mucosal type HPV in SCC patients with normal immunity has not been studied extensively. Sixty skin biopsies from immunocompetent SCC patients and 60 benign skin specimens were evaluated for mucosal type HPV DNA using polymerase chain reaction (PCR) and immunohistochemistry (IHC). Mucosal type HPV DNA was detected in 18 of 60 cases (30%) and in 7 of 60 controls (11.6%) using PCR. HPV immunostain was positive in 16 of 60 cases (26.6%) and in 15 of 60 controls (25%). Mixed infection with HPV 18, 11, 6 was found in half of the SCC cases. The most prevalent subtype was HPV 18 followed by HPV 6 and 11. The frequency of HPV DNA was significantly elevated in our cases compared to controls (P value <0.01, OR=16.8, 95% CI: 3.3-74.9). Our findings suggest an association of mucosal type HPV, especially HPV 18, with skin SCC in Iranian patients with normal immunity.