I qualified as a doctor in 1960, but I don’t consider myself as having taken up science until about 1970. My interest in the scientific method was prompted by my interest in the natural history of breast cancer.

Simple observations in the clinic were enough to convince me that we didn’t understand the disease, and that the futility and cruelty of the radical mastectomy was based on an article of faith. I then took my dilemma to my brother Harold Baum, a distinguished biochemist. He described to me the principles of scientific philosophy, and suggested – to my horror – that medicine might not be a science. I started reading primers in the philosophy of science, and was much taken with the teachings of the philosopher Karl Popper, whom I met a couple of times.

My next deliberate move was to take myself off to Pittsburgh to work with the oncologist Bernard Fisher, who was applying the scientific method by way of the randomised controlled trial. On my return to the UK, I set up a large collaborative group and joined the network of breast cancer trialists whose contributions lead to breast conservation and adjuvant systemic therapies, which have contributed to the 30 per cent fall in breast cancer mortality since 1985.

Michael Baum is coauthor of Breast Cancer (buy this book from Amazon (UK) or Amazon (USA)), and coeditor of History and Advancement of Anastrozole in the Treatment of Breast Cancer (buy this book from Amazon (UK) or Amazon (USA)).