Botanical formula improves effect of tamoxifen drug in ER+ human breast cancer

Researchers at the Cancer Research Laboratory, Methodist Research Institute, Indiana University Health found that a botanical formula for breast health inhibited the growth of estrogen receptor-positive (ER+) human breast cancer cells. More importantly, the researchers also found that the formula enhanced the anti-cancer benefits of the drug tamoxifen in the treatment of breast cancer. These results were presented today at the American Association for Cancer Research Annual Meeting 2015.

The study, "BreastDefend enhances the effect of tamoxifen in estrogen receptor-positive human breast cancer in vitro and in animal models in vivo," tested the effects of tamoxifen and the botanical formula alone, and together in combination against ER+ human breast cancer in an orthotopic model (human breast tumor cells implanted into mammary pads of mice). In this in vivo model, tumor growth was induced with the hormone estradiol. Results demonstrated that the formula significantly enhanced the effects of tamoxifen against the growth of human breast tumors. In vitro model analysis demonstrated that alone, the formula worked as well as tamoxifen against ER+ breast cancer cells; combined with tamoxifen, the formula increased apoptosis (cell death) with favorable effects on the expression of genes associated with specific molecular mechanisms in cancer.

The breast formula has been shown in 3 previous studies to suppress the growth and migration of human breast cancer cells, through downregulation of specific genes involved in breast cancer growth and metastasis. A 2012 orthotopic study on the formula, published in Oncology Reports, demonstrated that the formula significantly inhibited the growth and breast-to-lung metastasis of triple-negative breast cancer. However, this recent study is the first to indicate the formula's ability to enhance breast cancer treatment when used in conjunction with the anti-estrogen hormone therapy drug tamoxifen.

"These results showing that the botanical compound enhanced the effects of tamoxifen on breast cancer cells and inhibited tumor growth are very encouraging," concludes principle investigator, Dan Sliva, PhD. "The findings support the potential of the compound to be an important adjuvant for clinical use in conjunction with tamoxifen against aggressive breast cancer. The genetic mechanisms for these effects were shown in the cancer cells in vitro, and in the tumors in vivo."

The formula incorporates eight researched ingredients into a single supplement designed to promote breast cellular health and support the immune system. The key compounds in this formula are an enhanced bioavailable form of turmeric; diindolylmethane (DIM), an active byproduct of cruciferous vegetables known for promoting healthy estrogen metabolism; extracts of the medicinal herbs, Astragalus membranaceus and Scutellaria barbata; the bioflavonoid quercetin; and a blend of several species of botanically-grown mushrooms.

"As a dietary supplement, this formula offers a safe and effective approach to enhancing the anti-cancer benefits of a well-known hormonal therapy for breast cancer," states Dr. Isaac Eliaz, MD, MS, LAc, developer of the formula and one of the study's co-authors. "We're excited by the potential of this formula as demonstrated now in multiple preclinical studies. Progression to human clinical trials is urgently needed."