The friend: Alexander Masters

I was just putting the finishing touches to an explanation of mathematical group theory for my biography of mathematical prodigy Simon Norton when Dido Davies – the wizard who advises me on all my writing, an editor of genius, without whom I wouldn't feel confident about a single page – rang up to tell me she was going to die in six weeks' time.

"My shit was yellow. Nothing else. A small gall bladder problem, the doctor said, and sent me for an ultrasound." Dido has a peculiar love for hospitals and so it was "with jollity" that she'd lain down on the bed and chatted with the young man as he smeared Vaseline over her abdomen and began snapping watery shots of her innards.

"Then I noticed that he had stopped chatting back, and he was concentrating his gadget on a place I knew wasn't my gall bladder."

He left the room and returned with another man. They began to nod and whisper.

"When I was 10 years old and hanging was legal," she told me a few days later, sitting in the Cambridge University Library, "I'd occasionally come across a remark in the newspapers: 'The judge sentenced him to death.' I understood this to mean that the poor prisoner, weak from months of bread and gruel, standing in the dock, had so many sentences hurled at him by the outraged judge – Why did you break into her flat? What caused her to annoy you? You were there, admit it! How long had you known her? Why did you strangle her? – that he collapsed and died from the exhaustion of answering them."

She paused, and gathered breath. "My sentence has been delivered in a single sentence: 'You have a 10cm tumour on your pancreas.'"

We'd both seen the effects of pancreatic cancer. Dido had met our friend Adrian coming down the library steps earlier that year, blinking at the sunlight, muttering about a slight pain in his side. Five weeks later, he was laid out in his mother's sitting room, in a coma. The day before Adrian died, I drove up from London, to touch him and say goodbye. His skin was draped across the bones of his face like a sheet.

There aren't that many times I've seen real courage: the sort that makes you start with admiration each time you remember it. Top of my list for biblical chutzpah is Dido's bemused calm during those days in which she was waiting for the pain to begin. "Well, I've had a nice life," she said, scooping up the pages I'd brought with me. "Now, shall we go through these in Waitrose cafe? It's cooler there."

We first met at St Edmund's College, Cambridge (Dido was an English research fellow; I was making an inane attempt at a physics PhD). She was finishing her award-winning biography of the comic novelist William Gerhardie.

"I need someone," she said one night in the bar, after clambering through the window because the doors were bolted, "to edit the manuscript."

"Me!" I jumped.

After Gerhardie, she had an idea for some sex books. We wrote these together in rented apartments in Ireland, India, Australia, New Zealand; set up computers at either ends of a room and raced through the chapters alternately: if she worked on Macho Does Not Prove Mucho, I tackled Can A Woman Tell Your Size Without Undressing You? The next day we swapped over, tore out each other's weaknesses, added a pile of new stuff, and flung the section back.

Dido fronted them under the pseudonym Rachel Swift. Two became bestsellers. One sold in 17 languages. For a while Dido was an amused agony aunt on the Sunday Sport.

Nothing is certain – that's the number one cancer cliché. I went with Dido to the doctor's surgery to hear the details of the diagnosis. The GP seemed quite chirpy. Further tests had revealed it was pancreatic neuroendocrine cancer – still cancer, still frequently fatal, but a whistle of relief. It's what Steve Jobs had, and why he invented the iPad, the iPhone, Apple TV. If he'd had the ordinary pancreatic cancer, he'd have been dead before the MacBook. Neuroendocrine tumours can be very slow-growing, and Dido's are small. Some people last the rest of their natural life with them. After two weeks of thinking she was going to die before Christmas, apparently she wasn't.

Immediately, the glorious NHS had Dido on the operating table. The surgeon explained the high mortality rate. "Eight hours in theatre. No one else booked in for today – it's only you."

They almost cut her in half.

Then pinned her together again with 45 staples.

I went to visit the next day, bringing a chapter of hers I'd just edited. Her bed was in the intensive-care unit, at the far end of a hushed corridor.

"I'm dizzy with how wonderful this National Health Service of ours is," she muttered through her morphine. Then, noticing my bag: "Are those pages I see? Literature? How horrid. I'd rather you'd brought me whisky."

She drew a self-portrait in bed, vividly illustrating the yellow, red, green and cloudy fluids the tubes transported. "I'm marvellously multi-coloured," she texted, with photomessages.

A couple of weeks later, her first day home, she reported: "There are many blissful moments in this process. I was making coffee when I realised that the roof was leaking: I could hear the sound of water pouring from a height. But I couldn't find where the leak was, until I realised it was me. It didn't hurt. I tipped myself over the sink, got all the liquid out, slapped a plaster across the staples, went back to bed." She made a lively recovery.

Nothing is certain. Two years after that, at a routine consultation, Dido was told that she needed chemotherapy.

"We return to the soar and the plunge," she said. "You're not going to die, yes you are, no you're not. Whoops, sorry, yes you are."

LTRDSW: that's Dido's favourite editorial mark. It means: don't coerce, don't spoon-feed, stop telling readers what to think every time you describe something; Let The Reader Do Some Work. Those blasted six letters have chased me across hundreds of drafts. But LTRDSW can turn the tables on you.

After an important scan, the specialist announced in a neutral voice, "I'm still optimistic."

Still? Still? What exactly does still mean? This is what LTRDSW is all about: the beautiful imprecision of language; its unclear subtleties of interpretation. Did he mean: "Your case is so promising that it'll take much more than a setback like this to make me gloomy"? Or did he mean: "There's still just, just barely, a tiny, weeny little bit of room left for optimism"?

Dido and I split up 11 years ago, but we still batter at each other's work. If one of us is getting close with a proposal or a manuscript, we go through pages almost every day, by phone, by email, by meeting in Cambridge or London or in Great Snoring – wherever I'm living at the time.

We've evolved an excellent system of encouragement and damnation over the past 25 years. Half-ticks, ticks, double ticks, quarter-ticks, doodles in the margin to make fun of embarrassing mistakes, the rare and coveted triple tick, mocking tones of voice on the phone when the other is getting petulant about having full paragraphs, complete pages, sometimes entire chapters torn out and dumped in the bin.

I like to spend seven hours fussing over three words to describe a hedge. ("Must you use all these summarising adjectives? If the infernal hedge is magnificent, describe it with magnificence, not by saying 'magnificent' five times.") By contrast, Dido is drawn to sensitive sentences. She loves the poignancy of history, reflections on the omnipresence of ancestors, and slips the word "whisper" into her pages whenever my back is turned. In revenge I scribble in her margins "Waft ahoy!"

Neuroendocrine tumours are among the rarest of rare cancers, but a lot of people have them. Around 3,000 cases are diagnosed each year in Britain (compared with 48,000 for breast cancer) but, because of the long survival times, this trickle fills a large pool. There are often no symptoms: it sneaks about you on tiptoe. It is (appropriately for Dido) a whispering disease.

When there are symptoms, GPs frequently misdiagnose irritable bowel syndrome, Crohn's disease, peptic ulcers or fussing.

Dido began chemotherapy. Every three weeks for five months we met outside the Royal Free hospital, bearing packed lunches and manuscripts. Our day – and her three poisons – began at 8am. I was finishing The Genius In My Basement. A murder mystery she was writing was galloping to completion; but a second book on Thomas More had run aground. She'd lost her appetite for his wilful, self-imposed martyrdom. Her snappy style had become silted in waft. For 11 hours, with faultless good humour, the hospital staff swapped drips, extracted blood samples and attended to the beeping fluid pumps as Dido and I haggled over paragraph changes and lost pens under the bedclothes. We did not limp out till gone 7pm.

To pep up her immune system, I ordered tablets by the Titanic-load: shark liver oil (rich in immune-boosting alkylglycerols); Coral Legend (keeps Japanese islanders alive to the age of 105); Green Defence ("pre-digested supergreens in a probiotic powder"); Three Immortals (no idea, sounded promising). When Dido protested that she couldn't swallow them all, I suggested there was something wrong with her willpower. Once, I came up to visit her in Cambridge, bringing blueberry juice concentrate (antioxidants) and nanotechnology curcumin powder (cell-profusion suppressant), dumped the bag on her table in the library, and started pestering her about a drawing I'd done (critical to chapter 17) of Simon-the-prodigy being turned upside down in a bath. "Is that the only reason you want me to stay alive," she exploded, "so I can do your fucking editing?" All around us there was a temporary hush of pens, then the scratching of scholarship returned.

Words play a vital part in her recovery. She calls her tumours "the bores" – lower case because "they are silly, empty things which must not be given too much attention". The three drugs infused during chemo were "The Thugs" – permitted upper case because they had been invited in.

"If you hire three heavies," she remarked on days when she felt ghastly, "to whack and kick and pummel at the bores, you've got to expect that in their enthusiasm they will inflict a bit of inadvertent damage, too."

Meanwhile, the chemo work is paying off. Dido, recovered from the side-effects ("And kindly put in that I have not lost one strand of my hair – in fact, it's even better than it was"), is throwing herself at her two books with a vigour like ("Oi, oi, you swine, not 'like', that's a 'such as'") I've never seen before. The interrupted murder mystery, Raven Black, has got "even more contortionously devilishly devious". Thomas More has shaken off waft and returned to the splendid voice of healthy Dido Davies – the voice I am so much in debt to in my own writing.

"I gather you are an author?" the consultant announced when Dido sat down for her appointment at the Royal Free, having assessed all the details of her case. "Good. I expect to read many of the books you have left to write."

The husband: Nicholas Blincoe

My wife was diagnosed with breast cancer last February, so close to the beginning of the year that blocking off her treatment on a calendar felt like planning a sabbatical. This was our career break – the year of cancer – and I found comfort in knowing that the treatment had become so routine, we could diarise it. By autumn, however, I would have liked a sign that things were going well. Unfortunately, a new biopsy revealed cancer on a lymph node. The question now was, should Leila have more surgery? Or should she keep to the old schedule, as though the discovery was unimportant? A nurse explained that the choice ultimately depended upon her perception of risk.

"Some people would never dream of crossing a road except at a proper crossing," she said. "Others wait for a quiet gap in the traffic and then cross. And some people just walk straight out into traffic without looking."

"Hang on, who walks into traffic without looking?" I interrupted. "I understand choices can be subjective. But, sometimes, people don't evaluate risk because they're stupid."

The nurse had been talking to Leila, but now turned to me. "People have made that observation before. Mostly men, actually."

In a thousand different ways, breast cancer reinforces the differences between men and women. It is the most common form of cancer, with 48,000 cases diagnosed each year, and 99% of its victims are women. On the most accepted projections, one in eight women will develop it in their lives. Unless they are fortunate enough to be single or lesbian, their primary carer is likely to be a man. Now, the nurse seemed to be saying, my effectiveness as a carer was limited by an ultra-masculine grasp of mathematics. If so, she had the wrong couple. If either of us could get our heads around the calculus of risk, it was Leila. I struggled through my O-level while she won a maths scholarship to the Sorbonne.

But, to be fair, the nurse was trying to make a slightly different point. She was asking what kind of choices Leila could live with, when cancer means thinking about unbearable possibilities every day.

When Leila was first diagnosed, it was the last time we knew anything with certainty. Everything that has happened since has happened deep inside her body. In this fog of unknowing, I had trusted completely in the treatment calendar. When the calendar broke down, I felt a wave of helplessness.

The nurse was right that men think differently about their health from women. Twenty years ago, soon after Leila and I met, she telephoned to tell me she was ill with a temperature of 39C. I said, "Well, I won't bother you then." She spent a feverish night expecting me to turn up with medical supplies and an apology, and was amazed that I never did. At the time, my attitude was: if you're ill, who needs an audience? I would have said I was being stoical, but I wonder. What looks like stoicism might just be passivity dressed in heroes' clothes. It may even reflect something darker: a kind of fatalism.

I heard this fatalism in the answer Danny Baker gave on Desert Island Discs to a question about his fight with throat cancer. "You don't fight cancer," he said. "You're the battleground. Science is fighting it. You're Normandy beach, Hastings in 1066." Baker was claiming to be a warzone and I understood why that was comforting: I am blasted heath, oh yes! I am nuclear winter, hoo hah! But I also knew this would be no comfort to Leila. She'd gone through months of chemotherapy, was looking at daily radiotherapy, and had now been told she should consider more surgery. She was ready to accept that it was science's war. But she was being zapped and cut and swilled with poison and, frankly, when the results seemed so uncertain, it was perverse to say: yes, life can be cruel and barren, bring it on!

Before we knew our year of cancer had even begun, on the bus ride to the hospital for Leila's very first operation, I had amused myself doing a magazine quiz to calculate my emotional intelligence. I failed: it seems I have disastrously low levels of fellow-feeling. It was an ominous start to my career as a carer. While Leila was in surgery, I consulted a guide for carers published by Macmillan Cancer Support, entitled Hello, And How Are You? One chirpy section offered tips on how to organise a funeral, but the overall message appeared to be that carers should look out for themselves. A friend whose wife had just completed a course of chemotherapy had warned me about this. "People talk the most incredible guff about how, if you're a carer, you should care for yourself." He thought it was mad. "The fact is, you just have to do your best to care for her."

At this point, we thought Leila's tumour was pre-cancerous, so I assumed I could keep my caring levels at a low simmer. Even when the operation took longer than expected, I had no particular worries as I wandered down to the local patisserie to buy a bun. Later, I did wonder if I should have bought Leila a bun, too. When she surfaced from the anaesthetic, the senior surgeon used the empty patisserie bag to sketch a diagram of the operation. She had overrun because the tumour was larger than expected. On her diagram, she showed how she had removed a triangular piece of flesh, maintaining a margin around the tumour so that the biopsy could check for any stray cancer cells in the surrounding tissue.

With the biopsy came the diagnosis of cancer. Worse, there were signs of aggression that meant it would be categorised as a Grade 3. In retrospect, this became the pattern for the entire year: the news was always worse than we expected.

Modern cancer hospitals such as the one treating Leila have embraced a form of democracy in which oncologists, surgeons, pathologists and specialist nurses debate individual cases and agree upon a treatment. This was how our original cancer calendar was drawn up: around a table, with the entire team chipping in. The only person missing is the patient, which adds yet another layer to the many levels of helplessness that cancer induces. As the year passed, I learned my chief job as a partner-carer was to help Leila cope with her distance from the team treating her.

The hospital's own attempts to bridge this gap could be comical. Waiting to meet the senior oncologist, we sat in a curtained booth listening to him moan tetchily that he was in a hurry, before he pulled back the curtain and swept through, as handsome and imperious as any fictional doctor. Other team members were prickly in plain sight. When Leila detailed some of her most persistent symptoms, a young registrar responded by asking why she wanted to look at "the black side". She might have told him, with a life-threatening disease, the black side comes free.

We asked for lifestyle advice and found the hospital was disinclined to recommend anything but eating and sleeping – even frowning on exercise in case a sports injury caused their calendar to be suspended. Leila was asked to provide a list of the supplements and vitamins she took in her pre-cancer life, in case any interfered with her treatment, but received contradictory advice from the doctor, the pharmacist and the hospital's own nutritionist. It was a relief when the Scottish oncologist solved the issue by airily proclaiming that he could see no problem with Leila taking anything she wished, but only because he could not believe anything could withstand his aggressively toxic chemo regime.

Throughout, I kept returning to the quiz that scored my empathy levels. A friend suggested I had failed because I'm "spectrumy". This seemed to chime with the nurse's accusation that my attitude towards risk was too rational and masculine. The irony is that cancer hospitals are ultra-rational. Cancer therapy is as much about treating statistics as people; in fact, rather more so. Because cancer's movements are so unknowable, only the statistics provide a way to predict its moves, stymie its operations and burn its fields, to use Danny Baker's war analogy.

For a hundred years, the only response to breast cancer has been over-treatment. Most women with Grade 3 cancer lose one or more breasts as well as their lymph nodes. Leila is lucky in that her team is acting on statistics that show when a cancer is caught early, as hers was, it is possible to under-treat and get the same results. In this sense, her treatment is experimental, which brings new anxieties but also unexpected moments of power. The discovery that the cancer hasn't been entirely cleared by chemo is bad news, but it also means she is no longer caught in a system that prefers her passivity. She has a choice to make: should she break with the calendar and undergo a new round of surgery, or should she continue with scheduled radiotherapy?

It is not a decision she can make alone, however. She and I talk late into every night, while she has long telephone calls to her brother and sister. We go to a Harley Street consultant, and we spend hours discussing the issue with a friend who is a doctor. Our discussions go backwards and forwards and round and round.

I don't know how good a carer I have been. Most of the time, I feel I am guarding my private portion of fear and resisting taking on any more. I swear I can actually feel my mind repressing emotion. If I needed proof, it comes when I hear Mary Berry describe a perfect brioche on TV and my eyes start to prick. If I have learned anything from this brush with cancer, it is that patisserie play an important role in my psyche. But however poor I am as a carer, this is why Leila needs a carer: to help her keep her strength while she asks questions.

Leila decides against a further operation. There may be tough decisions down the line, but this one feels right and comes with an overwhelming sense of relief. Maybe no one ever really fights cancer, but with luck and support, we begin to feel there will always be a good chance of out-thinking it.

The mother: Amanda Brooke

Nathan was a healthy 10lb 6½oz when he was born, and as I charted my son's growth in his baby development book, I was expecting him to reach over 6ft tall. As I'm a single mum, he was going to be the man of the house, the one who would vet his sister Jessica's prospective boyfriends and the one who would take my arm as I teetered into my dotage. What I know now is that as I held that newborn baby in my arms, his skin still damp and wrinkled, he may already have had leukaemia and those development charts were going to be nothing more than a work of fiction.

It would be 21 months later when my growing unease would be given a name, juvenile myelomonocytic leukaemia (JMML). Nathan was diagnosed after a precautionary blood test for a virus revealed abnormal blood counts, but I already knew more than I should about this rare and awful disease. Six months earlier he had been diagnosed with a benign skin condition, a condition very rarely associated with JMML, so my first question was, "That's a really bad one, isn't it?" The oncologist replied, "No leukaemia is good" but he couldn't deny that, with a 40% survival rate, it was going to take "heroic measures" to save my son, a bone marrow transplant that would have significant risks of its own. Perversely, this deadly disease was indolent, so while the monster slept, there was time for Nathan to grow bigger and stronger for the fight that lay ahead.

We were sent home with no immediate plans for treatment and I was numb with shock. How could Nathan be so ill, yet look so well? I didn't know how to begin to pick up the pieces of our lives, or even if I could. One of my first tasks was to break the news to Jessica, who was nine at the time. I told her as much as I thought she could deal with and, while we faced our worst nightmares, Nathan remained blissfully unaware, untouched by the horrors he would one day have to face. He was still the same cheeky little boy who, when an elderly lady asked him his name, replied, "Sexy."

For 18 months, we lived in a torturous limbo where regular blood tests became the barometer for my hopes and fears, but not a day went by when I wasn't acutely aware of how blessed I was to have both of my children in my life. As we watched and waited, Nathan continued to grow and occasionally I could see glimpses of the man he was meant to become. Not many three-year-olds would have cheered as they approached the gates of the hospital or sat quietly on their mum's knee waiting for blood to be drawn. He was happy and trusting, but mischievous, too – when the nurse one day asked him which finger to prick, he pointed to one of mine. He took everything in his stride, it was his kind of normal and the best I could do for him was make him feel safe and secure and loved; in fact, it was all I could do. I couldn't fight his cancer for him or take it from him.

Not that I sat idly by as I waited. I couldn't. I became as informed as I could be about the disease and the treatment, and I became Nathan's advocate. I knew him better than anyone. I was the one who could spot the signs when he wasn't his usual self but then, when the decision was finally taken to go ahead with a bone marrow transplant, I felt guilty. Why hadn't I noticed the change in the size of his spleen or the other subtle signs that the monster had started to wake up? But most of all, how could I feel almost relieved that the waiting was over, knowing full well that it wasn't going to be me in the firing line?

It took another six months to make all the arrangements because we were relying on the generosity of an unrelated bone marrow donor. There were lengthier stays in the oncology unit at Alder Hey children's hospital but Nathan adapted as always. He loved the place, even as the procedures became more unpleasant; the bone marrow harvest, the line insertion, blood transfusions – these were all accepted without question or complaint because he was with people he trusted and, in some cases, loved.

The only thing neither of us adjusted to easily was the loss of privacy. Even when we had a room to ourselves, there was no controlling who came through the door. Nathan started wearing his Thomas the Tank Engine sunglasses to hide behind and, if that didn't work, he would simply say, "Me too busy" when he wanted to be left alone. Occasionally he would pretend to be asleep but would give himself away, obediently lifting up his finger with his eyes still closed so the nurse could place a clip on it to check his saturation levels.

Just when we thought we were ready, the transplant had to be delayed because Nathan's spleen had grown dangerously large. An emergency operation required an 8in incision to remove it but Nathan insisted on getting out of bed the next day, sitting in a chair to play with his cars and chat up his favourite nurse. I could only hope his determination and endurance would make up for the frailties his body was revealing each day.

I knew how brave he was, but it was only when he was finally admitted for the transplant and we spent a week in the main ward that I realised how different things might have been. Not all children were so accepting and when a little boy in the next bed started crying in terror as a nurse tried to take a blood sample, I took Nathan for a little walk, pushing his IV stand towards the playroom. I didn't want him to learn to be afraid; fear was the one thing I had managed to protect him from.

After a week of intensive chemo, we were moved into the isolation unit for the transplant itself, by which point Nathan was already dealing with the side-effects. He walked into our new room, took one look around and said, "Oh, oh, no sick bowls." But the vomiting was only the start of the horrors that would follow. The chemo burned him inside and out but it didn't deter him from doing whatever was asked of him. He had been wearing nappies during the night, but when I told him to call me if he needed the toilet, not wanting the urine to lie on his skin and burn him, he had dry nights from then on.

I stayed at Nathan's bedside throughout, occasionally leaving him for an hour or two to go home, but I felt fresh guilt at being allowed a break, knowing Nathan didn't have the luxury of time off from his illness. I relied on the amazing support of family to stay with him when I wasn't there and also to look after Jessica because, no matter how much I wanted to, I couldn't split myself in two.

Nathan's condition nose-dived when, with no immunity, he developed an infection, then another. His temperature sky-rocketed, his saturation levels dropped, there was the pain from his chronic diarrhoea that the morphine couldn't reach, his liver began to fail, then his kidneys, there was fluid on his lungs and, worst of all, he lost his smile. But each time the nurse asked him if he was all right, he'd reply, "Me fine."

"You're not fine," one nurse insisted and she drew pictures of three faces on a piece of paper: happy, neutral and sad. "Which one are you, Nathan?" she asked gently. He pointed to the sad face. But while the nurse could give him extra drugs, I could only watch on, helpless.

Then one day he seemed brighter and I thought we'd turned a corner. I really didn't think he was about to die, I was too busy living on no sleep and no fresh air, intent on encouraging Nathan through his daily battles and celebrating the smallest victories. One of the last things I remember him saying to me was, "Me not happy today" and when he died, I tried to tell myself that nothing bad was ever going to happen to Nathan again, but another voice in my head told me that it wasn't just the pain that had gone. All of those dreams I'd had for my son, that towering presence he was going to have in my life, it had all gone, too. But that was five years ago and I know differently now.

Nathan changed my view of the world and he changed me. His life is a huge source of inspiration in my life and it remains a constant that his cancer cannot take away.