High-risk human papillomavirus infection and overexpression of p53 protein in squamous cell carcinoma of the esophagus from Japan.

The present study was undertaken in order to investigate the possible involvement of high-risk human papillomavirus (HPV; types 16 and 18) or the overexpression of p53 protein in 123 Japanese patients with esophageal squamous cell carcinoma (SCC) from five different institutions. We detected HPV DNA in 30.1% (37/123) by in situ hybridization (ISH). Of these 123 cases, HPV type 16 was detected in 22 cases and HPV type 18 in 23 cases. In addition, HPV types 16 and 18 were detected simultaneously in eight cases. We found an almost similar incidence of HPV infection at five different places in Japan. Then, among these patients, 24 fresh tumor samples were also examined for screening the presence of HPV DNA using dot blot hybridization (DBH) and polymerase chain reaction (PCR). We detected HPV DNA in 20.8% (5/24) by DBH and in 12.5% (3/24) by PCR. P53 protein overexpression was found in 34.1% (43/123) by immunohistochemistry (IHC). Furthermore, in 43 cases from Kochi Medical School, the group positive for p53 antibody statistically showed worse survival rate than the group negative for both HPV DNA and p53 antibody. Judging from these results obtained in the present study, HPV infection and p53 overexpression are frequently detected and involved in the carcinogenesis of esophageal SCC in Japan. We also found that no significant geographical difference of both HPV infection and p53 overexpression of esophageal SCC was seemingly present in Japan.