The lithium salt of gamma-linolenic acid (Li-GLA) is growth inhibitory to pancreatic cancer cells in vitro and is reported to prolong the survival of patients with pancreatic cancer. The effect of Li-GLA on the growth of human pancreatic carcinoma in vivo is not known. In this study the effect of parenterally administered Li-GLA on the growth of human pancreatic carcinoma in nude mice was tested. Pancreatic tumours were produced in nude mice by subcutaneous implantation of MIA PaCa-2 cells. This cell line is sensitive to Li-GLA in vitro. Mice were randomly treated with intraperitoneal, intravenous or intratumoral Li-GLA. Each group also had controls. Both intravenous and intraperitoneal administration of Li-GLA had no significant effect on tumour growth or tumour phospholipid fatty acid composition. Intratumoral administration of Li-GLA was, however, associated with a significant antitumour effect. Within the limitations of this tumour model, the benefit seen with intravenous Li-GLA in patients with pancreatic carcinoma cannot be explained by tumour growth inhibition. Local administration appears to be more effective than intravenous or intraperitoneal therapy.
