Prostate cancer is the commonest non-skin cancer in men, with more than 40,000 new cases diagnosed in the UK each year. Development of prostate cancer depends upon testosterone (the male hormone), and medications that block testosterone (eg Androgen Deprivation Therapy, ADT) can help men to survive for many years. Men with metastatic prostate cancer are also treated with ADT, but recent evidence has demonstrated that there are survival benefits when chemotherapy given as well as ADT. Many patients now receive chemotherapy as first line treatment along with ADT in the context of newly diagnosed metastatic disease.