“…It is difficult to diagnose in a stage at which conventional therapy is likely to be effective, and is almost inevitably fatal. Laboratory studies of this tumour have been limited, by the lack of experimental models, to analysis of surgically excised tissue (Grant et al, 1978), pancreatic and duodenal juice (Allan & White, 1977) or other body fluids from cancer-bearing patients (Chu et al, 1977;Gelder et al, 1978). There is a need for detailed in vitro studies, but the difficulty of establishing the tumour in primary culture or as xenografts in immunedeficient animals is reflected by the limited number of successful reports in this field (Lieber et al, 1975;Owens et al, 1976;Yunis et al, 1977;Akagi & Kimoto, 1977;Schmidt et al, 1977;Courtenay & Mills, 1978).…”