This Article Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Vantyghem, S. A. Articles by Chambers, A. F. Search for Related Content PubMed PubMed Citation Articles by Vantyghem, S. A. Articles by Chambers, A. F.

Dietary Genistein Reduces Metastasis in a Postsurgical Orthotopic Breast Cancer Model

Departments of ¹ Pathology and ² Oncology, University of Western Ontario; and ³ London Regional Cancer Centre and ⁴ London Health Sciences Centre, London, Ontario, Canada

Requests for reprints: Ann F. Chambers, London Regional Cancer Centre, 790 Commissioners Road East, London, Ontario N6A 4L6, Canada. Phone: 519-685-8652; Fax: 519-685-8646; E-mail: Ann.Chambers{at}Lrcc.on.ca.

Metastatic spread, not primary tumor burden, is the leading cause of breast cancer deaths. For patient prognosis to improve, new systemic adjuvant therapies that are capable of effectively inhibiting the outgrowth of seeded tumor cells after surgical treatment of the primary breast tumor are needed. To facilitate the preclinical development of such therapies, relevant animal models of breast cancer metastasis that can mimic the postsurgical adjuvant setting are required. Here we developed a preclinical xenograft model of breast cancer metastasis where the primary tumor was removed by surgical resection before systemic adjuvant treatment. We used this model to assess the antimetastatic effect of postsurgical dietary intervention with the soy isoflavone genistein. The anticancer activity of genistein has been established in vitro and in vivo, however, few studies have tested the potential of genistein as an antimetastatic therapy. Using our model, we tested the efficacy of adjuvant treatment with genistein to inhibit the outgrowth of metastases postsurgery. To establish primary tumors, human breast carcinoma cells, MDA-MB-435/HAL, were implanted into the mammary fat pad of female nude mice. Primary tumors were left to grow for 5 weeks before being surgically removed. Mice were then randomized into two diet groups: control soy-free diet versus genistein-supplemented diet. Five weeks later, metastatic burden was assessed. Genistein reduced the percent metastatic burden in the lungs by 10-fold. These results indicate that dietary intervention following cancer surgery can affect the outgrowth of seeded tumor cells. The availability of well-characterized, clinically relevant animal models for studying factors that regulate metastatic outgrowth postsurgery will provide an important tool for developing new systemic adjuvant therapies.

This article has been cited by other articles:

				A. L. Allan, R. George, S. A. Vantyghem, M. W. Lee, N. C. Hodgson, C. J. Engel, R. L. Holliday, D. P. Girvan, L. A. Scott, C. O. Postenka, et al. Role of the Integrin-Binding Protein Osteopontin in Lymphatic Metastasis of Breast Cancer Am. J. Pathol., July 1, 2006; 169(1): 233 - 246. [Abstract] [Full Text] [PDF]

				A. F. Chambers Re: Medroxyprogesterone Acetate and Metastases: Of Mice and (Wo)Men J Natl Cancer Inst, August 17, 2005; 97(16): 1225 - 1225. [Full Text] [PDF]