Development of Animal Models for Studying How Timing of Surgery During the Menstrual Cycle Can Affect Breast Cancer Metastasis and Survival
Final rept. 1 Oct 2000-30 Sep 2002
UNIVERSITY OF WESTERN ONTARIO LONDON REGIONAL CANCER CENTRE
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The idea that timing of surgery for breast cancer during a pre-menopausal womans menstrual cycle can impact on survival has been a controversial one. Some clinical studies have shown improved survival when surgery was performed during the luteal phase of the cycle, while other studies failed to find this association. We previously showed that gene expression patterns varied in human breast tumors resected in different menstrual phases, and it is also known that normal tissues respond to cyclic hormones. Tumor cells shed at surgery at different menstrual phases thus might vary in their ability to form metastases, depending on hormone-responsive variations in host tissues andor tumor cells. Our goal in this CONCEPT project was to begin to develop animal models to test this idea. To mimic possible shedding of tumor cells at surgery, we injected cells into mice intravenously during either proestrus or metestrus. Initially, as a control, we used a non-breast cancer cell line, murine B16F10 melanoma cells. We found unexpected differences in the organ specificity of metastases from these cells. Based on our initial success in developing this model system, we will continue and extend theses studies in the future, to other cell lines and to mechanistic studies. Clarification of this phenomenon and its possible mechanisms has the potential to make an impact on survival from breast cancer.
- Anatomy and Physiology
- Medicine and Medical Research