Evidence for this theory was gathered from an examination of fluids that drained from the surgical sites. In these fluids, there was found to be various mitogenic factors normally associated with the wound healing process. Within these, scientist also found mitogenic factors that have been known to trigger breast cancer proliferation. In light of this discovery, further research has uncovered various mechanisms of how surgery induced cancer metastasis.
The first of these mechanisms involves cancer cell adhesion. In order to form tumors, cancer cells must attach to one another and do so through cancer cell adhesion. When tissue is exposed to a surgical environment, this adhesive ability increases. Another mechanism profits off the fact that after surgery, a woman's immune system is compromised, and the ability of white blood cells to seek out and destroy cancer cells is diminished. Because of this, cancer cells find it easier to metastasize, evade death, and spread throughout the body. A third mechanism involves angiogenesis. The primary tumor releases anti-angiogenic factors that actually prevent metastasis, and with the removal of this tumor comes to removal of these factors. In addition, synthesis of VEGF, or vascular endothelial growth factor also occurs post surgery; this growth factor is often a stimulator of tumor angiogenesis. A fourth and final mechanism of surgery induced metastisis is through the inflammation caused by surgery. Surgery causes inflammation at the surgical site, producing certain chemicals that trigger the activity of an enzyme called COX-2. This enzyme has been known to influence cancer cell growth as well as metastasis.