Animal models for hormone-dependent human breast cancer. Relationship between steroid receptor profiles in canine and feline mammary tumors and survival rate.

The present study shows that canine and feline mammary tumors, like human breast tumors, can be polyreceptive, i.e., they can contain estrogen (ER), progestin (PR), androgen, glucocorticoid, and/or mineralocorticoid cytosol receptors. Furthermore, a follow-up of 45 bitches with mammary carcinoma has indicated that the survival rate is significantly higher in animals with receptor-rich (ER and/or PR) tumors. This indicates that these canine mammary tumors should be evaluated further for their suitability as an animal model for hormone-dependent human breast carcinoma.