Nomination Summary for Ethinyl estradiol and/or mestranol (N91003)
Nomination Date: 03/11/1991
Nominator: Private Individual
Rationale: Use of oral contraceptive steroids has been associated with increased incidences of liver neoplasms in women. These compounds cause rapid increases in liver DNA synthesis at doses which are nearly equivalent to human doses. In many studies these compounds were concluded to be promoters of hepatocarcinogenesis. IARC monograph (Vol. 21) includes reviews of animal carcinogenicity studies on these compounds, but does not provide full information of strains of animals used, doses, or survival within individual dose groups.
NTP Principles: not specified