HPV and Oesophageal Carcinoma
from: Papillomavirus Research: From Natural History To Vaccines and Beyond (Edited by: M. Saveria Campo). Caister Academic Press, U.K. (2006)
Oesophageal squamous cell carcinoma (SCC) has a peculiar geographic distribution, with up to 500-fold variations in incidence between the low- and high-risk regions. The first reports suggesting HPV involvement in both benign and malignant squamous cell tumours of the esophagus date back to 1982. The abundant literature accumulated on this subject is summarised in this review. To date, 322 Oesophageal squamous cell papillomas (SCP) have been analysed using different HPV detection methods in 32 separate studies. HPV has been detected in 26.1% (84) of these cases. Until now, 1,485 SCCs have been examined by in situ hybridisation, of which 22.9% (341/1.485) were HPV DNA positive. This is almost identical with the 22.3% prevalence rate calculated among 2,645 SCCs analysed by PCR (589/2,645). HPV prevalence bears a close correlate to the incidence of SCC, being low (0-3%) and high (up to 80%) in the respective geographic regions. In large-scale seroepidemiological studies, the increased risk for SCC among HPV16-seropositives has reached OR (odds ratios) up to 15, even in low-incidence countries. Screening studies in high-incidence areas of China using balloon cytology sampling report high prevalence of HPV DNA among asymptomatic subjects. There are close human parallels to both SCP and SCC in the cattle, linked with BPV4 and alimentary carcinogens, present in bracken fern. in vitro experiments on HPV-positive cancer cell lines implicate similar molecular mechanisms to those involved in HPV-associated genital carcinogenesis. The current data suggest that the (multifactorial) aetiology of oesophageal cancer differs between the low- and high-incidence geographic areas. Oncogenic HPV types probably play an important causal role only in the high-incidence regions read more ...