I have been using a test with some of my patients who have had breast cancer called the ION profile from the lab, Metametrix. It is an awesome, though expensive comprehensive blood and urine test. What I have discovered is that these women consistently have a candida overgrowth in the gut and heavy metal toxicity - this is far too common. 

Heavy metal toxicity and Candida infection often occur simultaneously, and ideally are treated together. It will take at least 3 months and up to several years to clear these with proper diet and supplementation. Patients should have naturopathic guidance to both diagnose and treat both conditions.

In my experience, the best anti-candida substance is caprillic acid, followed by grapefruit seed extract and olive leaf extract. Sometimes all three need to be used together in difficult cases, along with an alkaline diet that restricts yeast, sugars, alcohol, peanuts, pistachios, vinegar, fermented foods, mushrooms, dairy and corn. Psyllium seed powder or other fiber would be taken with caprillic acid to increase bowel movements so that the body is not overwhelmed with the yeast die-off. Liver support is also beneficial, along with a good probiotic. For studies on the relationship between candida and breast cancer, see: www.mammalive.net/research/candida-and-breast-cancer

Mercury, copper, cobalt, nickel, lead, tin, and arsenic are know as metalloestrogens and are capable of binding to estrogen receptors, causing increased cell division in breast cells. We therefore need to remove sources of mercury from the body to deter cancer growth. The two major sources of mercury toxicity are fish consumption and dental fillings. For evidence on the effects of heavy metals on breast cells, see www.mammalive.net/research/breast-cancer-and-mercury