Breast cancer is driven by abnormal activity of the estrogen receptor (ER). Surgery and radiation therapy are effective treatment strategies when the tumour is confined within the breast. However, for cancers that spread out of the breast, the major treatment strategy is to completely eliminate activity of ER. This is called hormone deprivation therapy and has been employed for the past century.
For some, endocrine therapy can be very effective and has led to increased survival rates, but often the side-effects are debilitating and patients feel miserable. For others, this therapy does not work at the outset or their cancer becomes resistant. It is these highly aggressive therapyresistant tumours that kill patients with breast cancer. The overwhelming evidence indicates that hormone deprivation therapy has run its course in providing a survival advantage to people with breast cancer.
In this application, I propose a ground-breaking new treatment strategy that aims to rehabilitate rather than abolish activity of the ER, which drives breast cancer growth. This approach works by stimulating other hormonal pathways to push ER from "bad" to "good" DNA binding sites. This reverts normal cellular processes to impede ER action and halt tumour growth. I propose this can be achieved by repurposing drugs already used for other medical purposes, vastly increasing the speed of translating findings from the laboratory to the clinic. This strategy has strong potential to increase the lifespan of breast cancer patients who develop resistance to hormone deprivation therapies while improving their quality of life.