Gastric cancer in Gwynedd. Possible links with bracken

Abstract

Summary One hundred and one histologically confirmed gastric cancer patients in Gwynedd, North Wales, were matched by sex, age and social class to two hospital inpatients without cancer. Seventy-seven of the gastric cancer cases were also matched, using the same criteria, to a patient with a confirmed cancer of a different site (excluding oesophagus). A (Stocks, 1936(Stocks, , 1937(Stocks, , 1939 and although the disease is declining in the United Kingdom as a whole, the incidence in some administrative districts of Gwynedd (North-west Wales) is still substantially higher than the national average. This fact is strikingly displayed in mapped form by Howe (1970) and by Gardner et al. (1983).The high incidence in North Wales has never been satisfactorily explained although the possibility that environmental and/or dietary factors are involved has been investigated by a number of different authors (Stocks, 1957;Davies & Wynne Griffith, 1954;Howe, 1979). Furthermore, population migration studies among the Welsh (Armstrong et al., 1983) and other races (Haenszel, 1961) would seem to exclude genetic influences as a major factor in aetiology.Many parts of Gwynedd have in the past formed 'island communities' with static populations who could thus be exposed throughout life to local environmental carcinogens. Bracken (Pteridium aquilinum) is widely distributed and one of the most successful weeds worldwide (Fenwick, 1988). It is estimated that almost 7% of Wales is occupied by bracken, and in Gwynedd the coverage is substantially greater, exceeding 20% land cover in parts of the county (Taylor, 1985).Many investigators have demonstrated the carcinogenic potential of bracken in a variety of animal species. Chronic bovine enzootic haematuria, which may be followed by bladder cancer, has been reported among cattle from many parts of the world (Pamukcu et al., 1967;Jarrett et al., 1978). In all cases there is good evidence that the animals have been affected as a consequence of grazing upon growing bracken or of eating cut bracken used as bedding; and bracken feeding experiments have confirmed the association (Pamukcu et al., 1967). The earliest experimental work was performed on rats who were given bracken fronds in their diet for 2 months; all the animals succumbed to ileal adenocarcinoma (Evans & Mason, 1965). The same workers obtained bladder tumours in guinea pigs, but in mice the most frequent malignancies produced were leukaemias and gastric carcinoma (Evans, 1984). The same malignancies can also be produced by feeding bracken spores to these animals (Evans, 1986). Among the features of bracken carcinogenicity of special interest observed in these mouse experiments are the vulnerability of the young weanling animal and the relatively long latent period before gastric tumours develop (Evans, 1987

Quercetin elevates p27Kip1 and arrests both primary and HPV16 E6/E7 transformed human keratinocytes in G1

“…People exposed to bracken fern, whether as spores or in the diet, are at greater risk of developing oesophageal and gastric carcinoma (Hirayama, 1979;Galpin et al, 1990;Villalobos-Salazar et al, 1995;Alonso-Amelot et al, 1996Marliere et al, 2000). Moreover, HPV-16 has been found in up to approximately 50% of oesophageal cancers and precancers in developing countries (Chang et al, 1990;Togawa et al, 1994;Cooper et al, 1995;Suzuk et al, 1996;de Villiers et al, 1999;Syrjanen, 2002).…”

“…The highly variable geographical incidence of oesophageal cancer and of HPV detection in the cancer suggest a multifactorial aetiology and the involvement of environmental dietary cofactors (Syrjanen, 2002). Some human populations are exposed to bracken fern and this exposure has been linked epidemiologically to cancer of the upper GI tract in several parts of the developed and developing world (Hirayama, 1979;Galpin et al, 1990;Villalobos-Salazar et al, 1995;Alonso-Amelot et al, 1996;Marliere et al, 2000).…”

Geographic distribution of lung and stomach cancers in England and Wales over 50 years: Changing and unchanging patterns

“…Geographic differences have diminished since 1921-30, but it will be of interest whether they disappear in future, given the increasing homogeneity of food availability across the country. Bracken exposure has recently been suggested as a possible cause of stomach cancer in North Wales (Galpin et al, 1990), and is a factor prevalent in North Wales and the north of England, whose distribution at county level has presumably not altered greatly over time. Bracken is also similarly prevalent, however, in several areas in South and South Western England where stomach cancer risks are not high.…”

A New Facile Synthesis of D4-Pterosin B and D4-Bromopterosin, Deuterated Analogues of Ptaquiloside

“…Pta may represent a pollutant of foods derived from cattle [4]. A significant increase in gastric cancers in humans who spend their childhood in bracken-infested areas has been demonstrated [5], and milk has been proposed as the carrier, in which Pta would not be destroyed by pasteurisation. Pterosin compounds are also involved in many patented biomedical protocols for treating diabetes and obesity [6,7].…”