At the FCCC important translational possibilities for the BCRL were opened by using the mechanisms of initiation of cancer which led this group to develop strategies for its inhibition, capitalizing on the utilization of physiological mechanisms, such as pregnancy. This research has opened unsuspected avenues, such as the utilization of a single placental hormone, human chorionic gonadotropin (hCG), to protect the mammary gland of virgin rats from chemically induced mammary cancer. The protective effect of hCG, like that of pregnancy, is mediated by the induction of full differentiation of the gland, which eliminates the undifferentiated terminal end buds that are the targets of the carcinogen (J Natl Cancer Inst 82: 1286, 1990; Carcinogenesis 11: 1849, 1990; Br J Cancer 62: 243, 1990).
The relevance of these studies lies in the epidemiological data revealing that parous women have a four-fold lower breast cancer incidence than nulliparous women, therefore providing a physiological basis for the prevention of cancer in humans. The long lasting collaboration and partnership between Drs. Jose Russo and Irma H. Russo allowed for the demonstration that the mechanism of hCG’s action is mediated by a complex network of newly identified genes, one of which has been characterized as inhibin (Int J Oncol 4: 297, 1994). The discovery that hCG mimics pregnancy, that the protection conferred to the mammary gland from the initiation of the neoplastic process is equal or more efficient than that induced by the gestational process, and that it inhibits the progression of tumors, indicates that this model represents an ideal tool for breast cancer prevention and therapy (Cancer Epidemiol Biomarkers Prev 3: 353, 1994).
Since 1994, the Breast Cancer Research Laboratory at Fox Chase Cancer Center has grown, and currently there are 11 major research projects underway. These projects are an integral part of the laboratory, resulting in more than 180 publications, 165 published abstracts, and the publication of the book Biological and Molecular Basis of Breast Cancer, Springer-Verlag: Heidelberg, Germany (2004).