Tumorigenicity of arsenic trioxide to the lung in Syrian golden hamsters by intermittent instillations.

The tumorigenicity of arsenic trioxide was investigated in female Syrian golden hamsters which were given a total of 5.25 mg or 3.75 mg as arsenic by intratracheal instillations once a week. As controls, hamsters were treated with the vehicle, phosphate buffer solution. During the total life span, 3 lung adenomas were manifested in 10 hamsters or 2 lung adenomas in another 20 hamsters after 15 instillations of arsenic, while no lung tumor was detected among 35 hamsters in 2 control groups. The results show that arsenic trioxide is tumorigenic to the lung of Syrian golden hamsters.