Transforming endocrine therapy for breast and prostate cancer

Breast and prostate cancers are diseases driven by abnormal hormone receptor activity. Surgery and radiation therapy can effectively cure these cancers when the tumour is confined within the organ of origin. However, for cancers that have spread out of the breast or prostate, either locally or to other parts of the body, the major treatment strategy is to completely abolish the activity of the offending hormone receptor. This treatment strategy is called hormone deprivation therapy and has been employed for the past century. For some, this therapy can be effective for years, but often the side-effects are debilitating and patients feel miserable. For others, this therapy does not work at the outset or their cancer
rapidly becomes resistant. It is these highly aggressive therapy-resistant tumours that kill people with breast or prostate cancer. In short, the overwhelming evidence indicates that hormone deprivation therapy has run its course in providing a survival advantage to people with breast or prostate cancer. In order to make a major leap of progress towards curing these diseases and improving quality of life, new thinking is required. In this application, our outstanding team proposes
a ground-breaking new treatment strategy that aims to rehabilitate rather than abolish the offending hormone receptors that drive breast and prostate cancer, essentially changing them from tumour-promoting to benign. Importantly, we propose that this can be achieved by repurposing drugs from other medical purposes, which vastly increases the speed of translating findings from the laboratory to the clinic. Our exciting preliminary work suggests that this strategy has strong potential to significantly increase the lifespan of patients with therapy-resistant breast or prostate cancer. Another possible benefit of this approach is improved quality of life, which will be evaluated in near term clinical trials.