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.

• Status: Not yet recruiting
• Trial end date: 2021-12-01

Summary

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. Also, previous work has shown that retinoic acid, a chemical that results from the body's natural breakdown of vitamin A, should act against these CK5+ cells, but clinical trials of retinoids against breast cancer have been largely unsuccessful .Therefore we suggest that combination of retinoiac acid and tamoxifen was unsucssecful in treating breast cancer owing its ability to induce progesterone receptors and production leading to increasing numbers of CK5-positive cells which are therapy resistant . Although retinoid fenretinide reduced the accumulation of CK5+ cells during estrogen depletion. A study investigated the effects of all-trans-RA (atRA) on progesterone production in immature rat GCs cultured without gonadotropin. demonstrated that atRA enhanced progesterone production by upregulating the levels of steroidogenic acute regulatory protein (StAR) and cytochrome P450scc (Cyp11a1). Here, we suggest that tamoxifen or its combination with retinoic acid must be combined with anti-progesterone (Mifepristone) to achieve treatment with significant effect against early breast cancer. Moreover, Numerous studies have shown that CYP2D6 variant carriers (around 50% CYP2D6 variant carriers in Chinese population) will not benefit a lot from tamoxifen, and combined use of CYP2D6 inhibitors will further affect the efficacy of tamoxifen. In addition, All-trans-retinoic acid acts as an inducer of CYP26A1 expression. Which is the second expected cause of unsuccessful trial of Tamoxifen and retinoic acid in breast cancer treatment. Furthermore, The CYP26 inhibitor also induced expression of atRA-responsive genes. All-trans retinoic acid (ATRA) significantly inhibited aromatase activity in a concentration-dependent manner in microsomes isolated from JEG-3 human placental carcinoma cells. One study found that high retinol was significantly. associated with reduced breast cancer risk. Another found a significant trend of reduced retinol levels with more advanced disease stage. A study showed that intake of vitamin A and retinol could reduce breast cancer risk. Therefore we will take the benefit of cyp 26 inhibitor in this trial by combining Cannabidiol, a major phytocannabinoid, as a potent atypical inhibitor for CYP2D6.

• Phase: Phase 3

Details

• Lead Sponsor: Mahmoud Ramadan mohamed Elkazzaz
• Collaborator: Ministry of Health, Saudi Arabia
• Treatments: Alitretinoin; Cannabidiol; Epidiolex; Isotretinoin; Mifepristone; Tamoxifen; Tocopherols; Tretinoin