Human papillomavirus DNA in oesophageal carcinomas in South Africa

Using morphological criteria, the presence of human papillomavirus (HPV) in oesophageal carcinomas has been inferred in patients from Finland and South Africa. However, studies to demonstrate the viral antigen in tissue sections of these tumours have proved disappointing. This study investigates 48 archival oesophageal carcinoma biopsies from South Africa for the presence of HPV DNA using non-isotopic in situ hybridization (NISH) with HPV DNA probes to HPV 6, 11, 16, 18, 31, and 33. HPV DNA sequences were detected in 25/48 (52 per cent) oesophageal cancers. HPV 16 was present in 84 per cent of the HPV-positive cancers. A NISH type 2 signal pattern (punctate/dot) was present in all HPV-positive tumours. This signal pattern was previously shown to represent integrated HPV DNA within host chromosome. Integrated HPV DNA in oesophageal cancers has also been demonstrated in patients from China and Japan. In addition, the prevalence of HPV DNA in oesophageal cancers from high-risk countries like South Africa (52 per cent) and China (49 per cent) would appear to be consistent.