High Cancer Area Research Articles

Survey on levels of PCDDs, PCDFs, and non-ortho Co-PCBs in soil and sediment from a high cancer area near a batch-type municipal solid waste incinerator in Japan.

Survey on levels of PCDDs, PCDFs, and non-ortho Co-PCBs in soil and sediment from a high cancer area near a batch-type municipal solid waste incinerator in Japan.

A new papillomavirus associated with alimentary cancer in cattle.

A high incidence area of carcinoma of the alimentary tract of cattle has been reported1–4. The carcinomas are preceded by papillomas which may transform to malignancy. A papillomavirus was isolated from these warts and was shown to occur as a widespread infection of cattle in the UK2. In the high cancer area there is a marked increase in the overall incidence of this infection, an increase in the number of papillomas per animal and an increase in the number of specific sites of infection as compared with cattle from adjacent areas where cancers are not found. The papillomas are found in young animals but carcinomas do not develop until the cows are over 7yr old. There is strong circumstantial evidence1 that the factor associated with the increased multiplicity of papillomas and the subsequent malignant transformation is the ingestion of bracken fern. This plant is known to possess radiomimetic, mutagenic and carcinogenic activity. Preliminary experimental evidence supports the circumstantial data and we also have preliminary evidence of the presence of viral genome sequences, without production of virus, in the cells of carcinomas. In addition to the alimentary papillomas of the type described above, three more major patterns of bovine papillomatosis are found in the UK5 — cutaneous fibropapillomatosis, papillomatosis of the skin of the udder and teats, and papilloma of the penis. We have extracted papillomaviruses from all the above tumours, and our results, published in a preliminary form elsewhere5, indicate that the different lesions are caused by different papillomaviruses. Here we report the partial characterization of the virus involved in alimentary tract tumours and its differentiation from other bovine papillomaviruses. The system seems to present a dis-sectable model for investigating the mechanistic relationship between the viral infection and the ingestion of an environmental ‘carcinogen’.

Virus‐induced papillomas of the alimentary tract of cattle

An abattoir survey was carried out to determine the incidence and aetiology of squamous papillomas of the alimentary tract of cattle in Scotland and North England as they were suspected of being involved in the genesis of alimentary carcinoma in certain localized geographical areas. A total of 7,746 cattle of a wide age range was examined. Various subsets of this number were subjected to analyses of certain specific factors. The calculated overall incidence was 19% and the detailed site incidence and tumour multiplicity are given. The sites at which papillomas were found were identical with those at which carcinoma had been noted in animals from a high-cancer area. The number of sites affected by papilloma and the tumour multiplicity were much lower in the general population than in the high-cancer area. Inclusion bodies, identified by electronmicroscopy as virus, were found in tumour cell nuclei and a typical papilloma virus was purified from the tumours. The structure of the tumours is described and the possible plurality of bovine papilloma-viruses is discussed in the light of recent findings in the human viruses. The general interest of a naturally occurring and geographically localized oncogenic system, in which an environmental carcinogen and a virus might be involved, is extended.