Abstract: The present invention relates to pharmaceutical compositions comprising, as an anticancer agent (a) one or more compounds having the formula NO2-A-B, wherein A is a saturated or unsaturated hydrocarbon chain of 14-26 double bonds, and B is (CH2)m(COOH)n in which n is an integer from 0 to 2 and m is an integer from 0 to 2; or a derivative thereof in which the hydrocarbon chain has one or more than one substitution selected from the group consisting of hydroxy, hydroperoxy, epoxy and peroxy; (b) one or more compounds selected from polyunsaturated fatty acids (PUFA's) having a 16 to 26 carbon atom chain and 3 to 6 double bonds, and wherein the PUFA is covalently coupled at the carboxylic acid group to an amino acid selected from glycine and aspartic acid; (c) one or more compounds selected from unsaturated fatty acids having an 18 to 25 carbon atom chain and 1 to 6 double bonds and wherein the fatty acid has one or two &bgr;-oxa, &ggr;-oxa, &bgr;-thia, &ggr;-thia substitutions; or (d) one or more compounds havin