Up to 20 percent of invasive breast cancers are classified as triple negative, which refers to the fact that the cancer is estrogen receptor negative (ER-), progesterone receptor negative (ER-), and HER2/neu negative (ER-/PR-/HER2-). In other words, triple negative breast cancers do not express receptors for estrogen or progesterone and do not overexpress HER2. Triple negative breast cancer is also classified as basal-like breast cancer by some researchers.
Women diagnosed with triple negative breast cancer are more likely to be premenopausal than women with hormone receptor positive breast cancer. Treatments or foods that reduce the production of estrogen or block its effects in the body are not useful for this type of breast cancer.
Women with metabolic syndrome are more likely to have triple negative breast cancer upon diagnosis than women without it. A high cholesterol diet has been shown to induce angiogenesis and accelerate mammary tumor growth in a mouse model of triple negative breast cancer. On the other hand, use of lipophilic statins such as Zocor might reduce recurrence. The type 2 diabetes drug metformin has been shown to reduce the metastatic potential of triple negative breast cancer cells.
The studies concerning diet or specific foods that relate to triple negative cancer focus on hormone receptor status; HER2/neu status tends to be studied separately. However, the information concerning ER-/PR- breast cancer and diet is likely to be relevant to triple negative breast cancer since HER2- is the normal state (see also our web page on HER2+ breast cancer if you have ER-/PR-/HER2+ breast cancer). There are specific foods that have been found to be associated with lower risk of this type of breast cancer and some that are associated with higher risk.
Foods that reduce the risk of triple negative or ER-/PR- breast cancer
The following foods and spices have been found to be associated with reduced risk of triple negative or ER-/PR- breast cancer:vitamin D were three times more likely to develop triple negative breast cancer than patients with optimal levels. In other words, low vitamin D appears to increase the aggressiveness of breast cancer that develops.
Supplements for triple negative or ER-/PR- patients and survivors
There is no supplement or combination of supplements that has been shown to reduce the risk of triple negative or ER-/PR- breast cancer recurrence. Attempting to take advantage of the apparent treatment effects of micronutrients and other dietary components by using supplements carries the risk of adverse and paradoxical effects, including promoting breast cancer growth and metastasis.
What is known is that when a beneficial micronutrient is administered at low doses by consuming food, it is likely to have subtle chemopreventive effects, whereas when the same micronutrient is administered at high doses, it is more likely to have pharmacological effects, with mostly unknown results. It is best to obtain beneficial compounds by consuming food, if possible. The role of supplements is to make up for deficiencies that are difficult to correct through diet.
The following supplements generally been found to be safe and beneficial for triple negative or ER+/PR+ patients and survivors:
Supplement → Approximate dosage
Please consult your oncology team for advice concerning your situation and dosages. It might make sense to de tested for deficiency in vitamin D and plan for follow up to determine if your reading has reached a desirable level.
Foods to limit or avoid for triple negative or ER-/PR- breast cancer
The following foods have been specifically linked to increases in the risk of triple negative or its progression:
- Apricots, dried, non-US — potential for high cadmium levels
- Bacon and other processed meats
- Beef and veal, especially liver
- Corn oil
- High fructose corn syrup
- Indian mustard or black mustard
- Lamb, especially lamb liver
- Milk, full-fat
- Peanuts and peanut oil
- Pork and lard
- Rice from Louisiana, Thailand or India — potential for high cadmium levels
- Safflower oil
- Highly salty foods
- Products made from defatted soy flour, such as soy protein isolate & textured soy protein
- Soybean oil
- Sunflower seeds and sunflower oil
Fructose has also been shown to induce changes in triple negative breast cancer cells that may increase their aggressiveness, suggesting that patients should avoid concentrated sources such as agave nectar and processed foods sweetened with fructose, including beverages. Exposure to bisphenol A (BPA) has also been shown to increase proliferation of triple negative breast cancer cells.
Cadmium has been shown to promote the growth of triple negative cells. Copper has been shown to contribute to angiogenesis and metastasis of breast cancer, especialy in women with triple negative disease. Copper jewelry and jewelry made from copper alloys, such as red, rose or pink gold, are another potential source of copper exposure. Cigarette smoking is associated with significantly poorer outcomes for triple negative patients.
Supplements & vitamins to be avoided for triple negative or ER-/PR- disease
The supplements below have the potential to increase the risk of triple negative or ER-/PR- disease or its progression. That is not to say that most other supplements are safe to take; there are no relevant scientific studies concerning the interactions between most supplements and triple negative breast cancer.
It is important for triple negative breast cancer patients and survivors to eat a wide variety of the foods on our recommended food list and limit or avoid those on our avoid list, in addition to paying particular attention to the foods on the lists above. See also our article on how to optimize your breast cancer diet for information on what to eat during all stages of treatment and recovery.
Food for Breast Cancer triple negative breast cancer articles
Below are links to all of the other articles concerning triple negative breast cancer.
To see all of the news stories and studies concerning triple negative breast cancer, click on the tripleNegative tag in the list of tags directly below.