High-risk and low-risk human papillomavirus in esophageal squamous cell carcinoma at Mazandaran, Northern Iran

Cancers are the second most common cause of non-accidental deaths in Iran, following cardiovascular deaths. Mazandaran, near the Caspian Littoral at north of Iran have identified as a several-high incidence area for Esophageal Squamous Cell Carcinoma (ESCC) in the world. Several associated risk factors, such as dietary and cultural habits, infectious agents, nutritional deficiencies, too much use of tobacco and alcohol and infection to certain DNA tumor viruses (HPVs), including environmental and genetic factors are attributed to this disease. To explore this issue, we analyzed HPV DNA prevalence and HPV types together in relation to tumor sites a high-incidence population. Archived tissue blocks from 46, 69 and 62 upper, middle and lower third of esophagus, respectively from ESCC patients were evaluated for the presence of HPV DNA by PCR using the degenerate HPV L1 consensus primer pairs MY09/MY11. The positive specimens were evaluated by Real-time PCR to determine HPV genotypes. From the 49 HPV positive cases, of ESCC patients, 5 (23.1 %), 11 (55 %) and 9 (56.3 %) of upper, middle and lower third of ESCC specimens, respectively were positive by at least one high and one low-risk HPV genotypes. In general, HPV45 and HPV11 were the most common high- risk and low-risk HPV genotypes in HPV L1 positive cases, respectively, followed by HPV6, HPV52 and HPV39. Therefore, the high prevalence of HPV DNA in different anatomical sites of ESCC patients from the Mazandaran region in North of Iran provides more evidence for a role of HPV in this cancer.