Was the effect of E+P on breast cancer different in women who had used oral contraceptives in the past?
The analyses done so far do not suggest that use of oral contraceptives had any important influence on the breast cancer findings. Less than half of the women in this study had ever used oral contraceptives and the length of use was often relatively short (less than 5 years). With the small number of breast cancer cases that occurred in these women, these data do not provide a very clear answer to this question.
