Investigating the Potential Role of a Novel Quadrate Combination Therapy Mifepristone(Antiprogestrone), Tamoxifen, Retinoic Acid and Cannabidiol ( Selective Cyp 26 Inhibitor) for Treating Early Breast Cancer.

Investigating the potential role of a novel quadrate combination therapy Mifepristone(Antiprogestrone), Tamoxifen, Retinoic acid and Cannabidiol ( selective cyp 26 inhibitor) for treating early breast cancer. Breast cancer is the main cause of mortality among women. The disease presents high recurrence mainly due to incomplete efficacy of primary treatment in killing all cancer cells. Therapy resistance remains a major problem in estrogen receptor-α (ERα)-positive breast cancer. Half of estrogen receptor-positive breast cancers contain a subpopulation of cytokeratin 5 (CK5)-expressing cells that are therapy resistant and exhibit increased cancer stem cell (CSC) properties. Here, we propose a testable hypothesis that treatment of breast cancer with tamoxifen or retinoic acid or a combination of the two, may result in induction or conversion of some ER-positive breast cancer cells to ER-negative cancer cells expressing the basal cytokeratin-5 (CK5) via stimulation of progesterone receptors effect, and production . Therefore, we raised an issue with the answer " Why Antiprogestrone such Mifepristone and cyp 26 inhibitors must be combined with Tamoxifen or its combination with retinoic acid in the era of oncology for treating early breast cancer" .In fact, limited evidence has indicated that induction of CK5+ cells in ERα+ breast cancer is a unique effect of progestin (Prg) but many studies have demonstrated that progesterone (P4) increases CK5+ breast cancer cells. In case-cohort study of 405 incident breast cancer cases, elevated circulating progesterone levels were associated with a 16% increase in the risk of breast cancer. A study demonstrated that tamoxifen induced progesterone receptors (PGR) in short term treatment. Another study showed that High progesterone receptor expression correlates to the effect of adjuvant tamoxifen in premenopausal breast cancer patients. These CK5-positive cells are therapy resistant and have increased tumor-initiating potential. Als