International Agency for Research on Cancer (IARC) - Summaries & Evaluations


VOL.: 24 (1980) (p. 59)

5. Summary of Data Reported and Evaluation

5.1 Experimental data

Dapsone has been tested by oral administration in mice and rats, by intraperitoneal administration in mice and by prenatal and lifetime oral exposure in mice and rats. In three different studies in rats, high doses of dapsone induced mesenchymal tumours of the spleen in males (and of the peritoneum in two studies). An increased incidence of tumours of the thyroid was found in rats of both sexes in one study and in males in another study.

In mice, the experiment involving intraperitoneal administration of dapsone could not be evaluated. The other two experiments did not provide evidence of carcinogenicity.

Dapsone and its acetylated metabolites were not mutagenic to Salmonella typhimurium. Attention is drawn to the absence of studies on the teratogenicity of this compound.

5.2 Human data

Dapsone is used mainly in the treatment of leprosy.

Several cases of cancer have been reported in patients with dermatitis herpetiformis treated with dapsone. There was no evidence of an increased rate of cancer in patients with leprosy, many of whom would also have been treated with the drug.

5.3 Evaluation

There is limited evidence for the carcinogenicity of dapsone in experimental animals. The epidemiological data were insufficient. No evaluation of the carcinogenicity of dapsone to humans can be made.

For definition of the italicized terms, see Preamble Evaluation.

Subsequent evaluation: Suppl. 7 (1987)

Last updated: 7 April 1998

    See Also:
       Toxicological Abbreviations
       Dapsone (PIM 167)
       Dapsone  (IARC Summary & Evaluation, Supplement7, 1987)