Fibrosarcomas induced by cobalt chloride (CoCl2) in rats

Hyperlipaemia persisted for more than 12 months in rats treated with cobalt chloride, 9 of 20 treated rats and 1 control rat died within the first year, and 8 of the surviving animals developed fibrosarcomas--in 4 of these the tumour was far removed from the injection sites. The results are discussed with reference to the use of cobalt chloride treatment for anaemia in patients with chronic renal failure.