Mutagenicity of cisplatin and carboplatin used alone and in combination with four other anticancer drugs.

Mutagenicity of cisplatin and carboplatin was compared by using the drugs alone and in combination with bleomycin, 5-fluorouracil, vincristine and methotrexate in the Ames Salmonella assay employing the tester strains TA98, TA100 (excision deficient) and TA102 (excision proficient). Cisplatin showed the maximum yield of histidine revertants in TA98 and TA100 at 2 micrograms/plate followed by a decrease in the number of mutants/plate with increasing concentrations. In the excision proficient strain TA102, there was no decline in the number of mutants/plate even at a concentration of 8 micrograms/plate. Basically, similar results were also obtained with carboplatin but using higher concentrations of the drug. When cisplatin or carboplatin was combined with other anticancer drugs, there was no differential modification of mutagenicity of the 2 platinum compounds in any of the bacterial tester strains.