I think the way we think about cancer, the way we treat cancer, has dramatically changed in the last century. There is an enormous amount of options that a physician can provide today, right down from curing patients, treating patients or providing patients with psychic solace or pain relief.

This was yet another colonial fascination: to create the conditions of misery in a population, then subject it to social or medical experimentation.

Cancer's life is a recapitulation of the body's life, its existence a pathological mirror of our own. Susan Sontag warned against overburdening an illness with metaphors. But this is not a metaphor. Down to their innate molecular core, cancer cells are hyperactive, survival-endowed, scrappy, fecund, inventive copies of ourselves.

In Paris, friend of Bequerel’s, a young physicist-chemist couple named Pierre and Marie Curie, began to scour the natural world for even more powerful chemical sources of X-rays. Pierre and Marie (then Maria Sklodowska, a penniless Polish immigrant living in a garret in Paris) had met at the Sorbonne and been drawn to each other because of a common interest in magnetism.

I began wondering, can one really write a biography of an illness? But I found myself thinking of cancer as this character that has lived for 4,000 years, and I wanted to know what was its birth, what is its mind, its personality, its psyche?

Cancer has enormous diversity and behaves differently: it's highly mutable, the evolutionary principles are very complicated and often its capacity to be constantly mystifying comes as a big challenge.

I wanted to explore cancer not just biologically, but metaphorically. The idea that tuberculosis in the 19th century possessed the same kind of frightening and decaying quality was very interesting to me, and it seemed that one could explore the idea that every age defined its own illness.