Sodium diethyldithiocarbamate administration in nickel-induced malignant tumors

Studies were undertaken to ascertain the possible antitumorigenic effectiveness of sodium diethyldithiocarbamate (dithiocarb) on the development of tumors in rats following the muscular implantations of nickel subsulfide (Ni3S2). These tumors have histologic characteristics which suggest origin from striated muscle and have been classified as rhabdomyosarcoma. Most of the tumors metastasized. In two separate studies over a period of two years, a total of 100 four-month old Fischer rats received muscular implantations of Ni3S2. Of this total, 50 rats (25 males and 25 females) were treated with dithiocarb for a period of four to six weeks. Seventy-eight percent of the untreated rats developed sarcomas as compared to 32 percent of the treated rats. Analyses of the data revealed a striking difference in the sex responsiveness to dithiocarb. Of the 25 female rats with Ni3S2 implantations and treated with dithiocarb, only 12 percent developed sarcomas; of the male rats similarly treated, 52 percent developed sarcomas. The difference in sex response is statistically significant (p = 0.005). Therapeutic implications are suggested.