Why did I write The Emperor of All Maladies? A 56-year-old woman with an abdominal sarcoma, having undergone two remissions and a relapse, asked me to describe what she was battling. By the time I had finished answering her, I realised that I had written 600 pages. 

How did the book get written? When I first began to write the book, I suffered from the fallacy, as many first-time authors do, that the trick to good writing is good equipment.

Good writers must use good instruments, I thought. Great surgeons, I imagined, must operate with the surgical equivalent of Wusthof knives. Great cardiologists probably use high-end stethoscopes. So to be a great writer, I reasoned, I must have a great writing room. I emptied a study on the top floor of our house in Cambridge, Massachussetts, and bought a beautiful high-backed chair, a minimalist desk and a fountain pen that handled like a German revolver.

Then I sat in the room every evening staring at the wall, writing nothing. Three weeks went by, and not a single worthwhile paragraph oozed out. I moved myself to the living room couch, and spent the day staring into the garden. Nothing. The dining room table, with the books spread out around me. Nothing.

I went to sleep one evening, having produced another day of nothing. I woke up at about three in the morning, lying in bed, with my pillow propped up, and wrote four pages.

The trick to my writing, it turned out, was doing so exclusively in bed. The minute I even dared to discipline myself and write at the desk, I produced mounds of nonsense. Yet, sitting in bed, I wrote easily, effortlessly, fluidly. I became the master of perfect indiscipline. If I set myself fixed hours, or forced myself to write a certain number of words, I produced complete junk.

I once set myself a deadline: half a chapter a week, 20 minutes a day. The thought froze me instantly, like literary botox. I returned to my non-schedule: sleeping, writing 20 minutes, and then back to sleep. Breakfast in bed, with juice congealing on the sill: pages and pages began to pour out again.

Extract: The Emperor of All Maladies

In a damp fourteen-by-twenty-foot laboratory in Boston on a December morning in 1947, a man named Sidney Farber waited impatiently for the arrival of a parcel from New York. The "laboratory" was little more than a chemist's closet, a poorly ventilated room buried in a half-basement of the Children's Hospital, almost thrust into its back alley. A few hundred feet away, the hospital's medical wards were slowly thrumming to work. Children in white smocks moved restlessly on small wrought-iron cots. Doctors and nurses shuttled busily between the rooms, checking charts, writing orders, and dispensing medicines. But Farber's lab was listless and empty, a bare warren of chemicals and glass jars connected to the main hospital through a series of icy corridors. The sharp stench of embalming formalin wafted through the air. There were no patients in the rooms here, just the bodies and tissues of patients brought down through the tunnels for autopsies and examinations. Farber was a pathologist. His job involved dissecting specimens, performing autopsies, identifying cells, and diagnosing diseases, but never treating patients.

Farber's speciality was pediatric pathology, the study of children's diseases. He had spent nearly twenty years in these subterranean rooms staring obsessively down his microscope and climbing through the academic ranks to become chief of pathology at Children's. But for Farber, pathology was becoming a disjunctive form of medicine, a discipline more preoccupied with the dead than with the living. Farber now felt impatient watching illness from its sidelines, never touching or treating a live patient. He was tired of tissues and cells. He felt trapped, embalmed in his own glassy cabinet.

And so, Farber had decided to make a drastic professional switch. Instead of squinting at inert specimens under his lens, he would try to leap into the life of the clinic upstairs – from the microscopic world that he knew so well into the magnified real world of patients and illnesses. He would try to use the knowledge he had gathered from his pathological specimens to devise new therapeutic interventions. The parcel from New York contained a few vials of a yellow crystalline chemical named aminopterin. It had been shipped to his laboratory in Boston on the slim hope that it might halt the growth of leukemia in children.