Shoei-Loong Lin, Cheuk-Sing Choy, Wing P Chan und Ting-Kai Leung
Objective: In January of 2013, the National Institute of Health and Clinical Excellence of United Kingdom have announced that taking tamoxifen for five years could reduce breast cancer risk, include positive family history or chronic estrogen and phytoestrogen users. However, routinely oral intake of tamoxifen for breast cancer prophylaxis on high risk women is occasionally difficult because of its potential side effects. The intention of this study is to prove transdermal delivery by using minimal dose of tamoxifen and phytonutrients for breast protection. Methods: We retrospectively studied 2795 breast MRI images from Taiwanese women and classified them as either healthy or unhealthy according to BI-RADS categories. A subgroup of the study patients had received estrogen supplements containing estrogen components or phytoestrogen for at least 3 months. Based on breast MRI analysis, these 2 groups were compared and found significant different. The overuse of estrogen or phytoestrogen supplements can increase breast glandular tissue proliferation, as reflected in MRI images. Such proliferation may increase the risk of future breast cancer. We also studied the efficacy of tamoxifen and the phytonutrients to inhibit proliferation of mammary glandular cell, as well as their transdermal absorption in animal models. Results: We demonstrated cell proliferative change of normal breast cells (MCF-10a) under estrogen treatment. For studied of transdermal absorption by topical application, we used Franz cell with artificial skin membrane to demonstrate positive transdermal diffusion using animal urine/feces, blood samples and subcutaneous skin retention for HPLC analysis. Conclusion: We successful demonstrate the transdermal absorption of topical application of tamoxifen and phytonutrients; it may help to reduce breast cancer development in regular estrogen and phytoestrogen users.