Therapeutics in Active Prostate Cancer Surveillance

The numbers of men diagnosed with prostate cancer in the United Kingdom (UK) and worldwide is increasing. In the UK 46,690 men were diagnosed in 2014 alone and it is estimated this figure will be closer to 70,000 by 2030. A significant proportion of these men will present with organ confined and low or intermediate risk disease. There is increasing recognition that many men with low and intermediate risk prostate cancer do not need immediate radical therapy. There is sufficient evidence that pharmacological intervention used as short-term therapy in men with low to intermediate-risk disease can inhibit the growth of prostate tumours and delay or remove the need for radical therapy in men managed by active surveillance. Given the irrefutable role of the androgen receptor in prostate cancer pathogenesis it is logical to target this pathway as a method of inhibiting or delaying disease progression. This window study will be built on the known anti-androgen effects of apalutamide and investigate the efficacy of using it as a short intervention strategy to cause a physiological change in the tumour by reducing its volume. Tumour volume can be measured using the well-established place of mpMRI defined tumour volumes as a surrogate of disease presence and change. The rationale for a short duration treatment is that it will not have the long term debilitating effects of androgen deprivation on general health and prevent the onset of androgen resistance. It is anticipated that if successful, this approach could be a new therapeutic strategy for these men who otherwise are living and waiting for their disease to progress or not.