Why did you decide to write a "biography" of cancer?
I didn't want to over-anthropomorphise an illness. The book was originally entitled A History of Cancer, but as I took a step back I felt as if I was drawing a portrait over time of something very deeply examined, something very personal and something that keeps changing in its form and shape. "Biography" seemed to be a more accurate description.
You refer to cancer as a "modern illness". What do you mean?
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.
How do you explain the shame surrounding the disease for so long?
Part of it was that we knew so little about it. The modern idea of cancer doesn't even come about until the mid-19th century. And then breast cancer, for instance - a cancer that affects a sexual organ in women - was multiply shrouded in secrecy and shame. Also, the idea that it came from within, with no understandable cause, and had no clear treatment, made it very difficult to talk about. There's a phrase in Shakespeare: he refers to it as the "hidden imposthume", and this idea of a hidden swelling is seminal to cancer. But even in more contemporary writing it's called "the big C".
You depict the horror of how cancer can affect a patient, but you also describe it as beautiful. Can it be both?
There is a duality in recognising what an incredible disease it is - in terms of its origin, that it emerges out of a normal cell. It's a reminder of what a wonderful thing a normal cell is. In a very cold, scientific sense, I think a cancer cell is a kind of biological marvel. The stories of your patients are central to the book.
Was it difficult to write about people you were treating?
I anonymised all of them. So that was quite simple. The more difficult thing was to come to terms with moments of conflict. The stories are quite unsparing of both my patients and myself. There are times when I reach complicated conflicts with patients, when I feel as though I've let them down. All of that had to get into the book, because that is the experience of taking on cancer.
One of the things I was trying to get into the book was what the historical experience was like - as a breast cancer patient in 1890 or 1980, or as a breast cancer doctor in 1980 versus 2010. To write as a doctor was complex, because you are trying to be clinically accurate but also psychically accurate in your descriptions, and psychically honest with yourself. That was very hard to do.
Practically, how did you write the book while practising as a doctor?
I wrote it in short bursts, ten minutes, 20 minutes. For almost three or four years the book was a conversation that went on in my head - even while I was riding a bus, I was wondering about the connection between the way we imagine leukaemia in this day and age against the way we imagined it a hundred years ago. Every time I went to see my patients, I would ask myself: "What is the connection between this story of my interaction with this particular patient, and the much larger canvas of history that stretches across thousands of years?"
How do you deal with the endless hope, from patients and readers alike, for a cure?
One thing you learn is that hope is in fact a malleable thing. When you immerse yourself in medicine you realise that hope is not absolute. It's not that simple. A woman who has stage four metastatic breast cancer might have adjusted her hopes - what she really might be hoping for is a pain-free death, or a dignified death, or watching her daughter graduate from school or college in four months.
Patients are constantly reconciling themselves with their illness, and your job as a doctor is to facilitate that with truth and with honesty. And I think hope turns out to be much more complicated than we imagine when we think about it in absolute terms. Just as there is no archetypal cancer, there is no archetypal patient, and therefore there is no archetypal hope. l
Interview by Sophie Elmhirst
Siddhartha Mukherjee's "The Emperor of All Maladies: a Biography of Cancer" is published by Fourth Estate (£25)