A 2005 study concluded that soy increases colon epithelial cell proliferation measures in the sigmoid colon a common location of colon cancer. In the cecum and sigmoid colon the proliferation count increased as the serum soy concentration increased. Cells that multiply indiscriminately can encourage the cause of colon cancer.
In 2004, a study suggested that DNA damage by soy isoflavone metabolites plays a role in tumor initiation and that cell proliferation by soy isoflavones via estrogen receptors induces tumor promotion and or progression, resulting in cancer of estrogen-sensitive organs.
More Information On How Eating Soy Is Linked To Several Cancers. Sources: