Development of second malignancies in rats after cure of acute leukemia L 5222 by single doses of 2-chloroethylnitrosoureas

After cure of rat leukemia L 5222 in 79 BD IX rats by single doses of 1,3-bis(2-chloroethyl)-1-nitrosourea (BCNU) or 1-(2-hydroxyethyl)-3-(2-chloroethyl)-3-nitrosourea (Hydroxyethyl-CNU) a total of 9 rats (11%) developed secondary malignomas.