Animal models of breast cancer: experimental design and their use in nutrition and psychosocial research.

This is the second Special Issue addressing the diversity and use of animal models of breast cancer. The previous issue (Breast Cancer Res Treat 39:1-135, 1996), dealt with a variety of topics such as the characteristics of chemically- and virally-induced rodent models, immunobiologies of immunedeficient mice, transgenic mouse models, and models of metastasis. In the first part of this second Special Issue, the articles address animal models for studying life-style factors, including psychosocial, exercise, and nutritional research in breast cancer. In the second section, there is emphasis on the controversial area of dietary fat, with other authors addressing caloric restriction and dietary isoflavonoids, retinoids, and monoterpenes in the third part. In the final section, a series of authors provide suggestions for approaching various issues involving experimental design, including nutritional studies, drug screening models, statistical considerations, quantitation of tumor growth kinetics, and animal husbandry. These articles, and some additional issues raised during the previous Special Issue, are briefly discussed in this overview. They include a further evaluation of the relative merits of 7,12-dimethylbenz(a)anthracene and N-nitroso-N-methylurea as carcinogens, and of the use of the AIN76 and AIN93 semipurified diets in studies of mammary carcinogenesis.