Mammary-tumour incidence in Sprague-Dawley rats treated with 7,12-dimethylbenz(a)anthracene: effect of pregnancy and lack of effect of unilateral lactation.

Mammary-tumour incidence in Sprague-Dawley rats treated with 7,12-dimethylbenz(a)anthracene: effect of pregnancy and lack of effect of unilateral lactation.