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


VOL.: 24 (1980) (p. 259)

5. Summary of Data Reported and Evaluation

5.1 Experimental data

Spironolactone was tested by oral administration in two experiments in rats. An increased incidence of thyroid and testicular tumours was reported in one experiment but not in another experiment of longer duration with lower doses.

Attention is drawn to the absence of studies on the teratogenicity and mutagenicity of this compound.

5.2 Human data

Spironolactone is an aldosterone antagonist commonly used as a potassium-sparing diuretic.

Five cases of breast cancer were reported in women who had used a drug containing spironolactone. Four analytical studies, however, showed no consistent evidence of an association.

5.3 Evaluation

The experimental studies, while providing limited evidence of a carcinogenic effect, were difficult to interpret because of inadequacies and inconsistencies in reporting. Epidemiological studies have not confirmed the suspicion raised by case reports that spironolactone may cause breast cancer in humans. The data are insufficient, however, to permit confident exclusion of such an effect.

For definition of the italicized terms, see Preamble Evaluation.

Subsequent evaluations: Suppl. 7 (1987); Vol. 79 (2001)

Last updated: 7 April 1998

    See Also:
       Toxicological Abbreviations
       Spironolactone  (IARC Summary & Evaluation, Supplement7, 1987)
       Spironolactone  (IARC Summary & Evaluation, Volume :79, 2001)