Last Monday evening, Deborah Hutton was surrounded by her family, her friends, many of those who were caring for her in her illness, many of those with whom she was conversing on the blog, and the many people she had marshalled behind her cause to celebrate the publication of her book. Debs had put the question: 'What can I do to help?' And she answered it best - by doing so much herself.

That was how Deborah Hutton responded to her own cancer. By helping in the best way she could; by telling people how they can best help.

Any serious illness, cancer especially, is hard for everyone to deal with. But for the 739 people in this country who every day, every single day, receive the worst news imaginable when they are diagnosed with cancer, dealing with it is what they - and their families and friends - have to do.

What Debs gave all those around her and now, through her writing, to many, many people she had never met, and never would meet, is the way to do it. Her book is characterised by its driving practicality. How best to make decisions about treatment, of course - the big decisions cancer sufferers have to make. And, in the next breath, advising people to bring a bottle of elderflower cordial or pink ginger with you to hospital, because it does wonders for the taste of hospital water.

Her work in the book offers so much insight into every level of the experience of being ill. And does it in a way that almost makes you feel that the book could provide the answer to the difficulties of the day.

Her book is as exceptional as she was. And it reflected her. Her truthfulness; the descriptions in the book of the experience are searingly accurate and unvarnished. Some bad experiences, many very good experiences. All told in a way which leaves the reader utterly convinced both that that was what happened, and what Debs saw and described was the essential truth of the experience. Whether it be the day of the diagnosis, or the day Maggie the palliative care nurse first arrived, the descriptions make it so much easier for others to understand and face up to their own experiences.

Her ability to learn for everybody else: not just the book, but the blog, the ability to communicate to friends and family and the wider public. To make us all see things we would never otherwise have seen or thought about ourselves. How she was able to put that super competent, I-can-handle-it-myself-thank-you-very-much persona aside, and learn to say: 'Yes, I like that, thank you' or: 'You know you said absolutely anything ... well ... do you think you could possibly...?'

Her commitment to causes: she couldn't but get hopelessly engaged in what she was doing. Helping those who suffer. Campaigning to stop the young, particularly young girls, from smoking. Preparing to embark on the cause of getting 2p from every pack of cigarettes to go directly to the underfunded cause of research into a cure for lung cancer, one of the largest killers around, particularly of younger women.

She had an NHS team who were as exceptional as she was. She had very many friends whom she described as 'part of a world-class network of friends and neighbours who were determined from the outset to save me so much as a second of unnecessary stress or strain'.

She had an amazing support team of 18 'colander girls' who ran a supper rota for Debs with the numbers ever expanding over the last six months. And, of course, her family: her mother, Danthe, her sisters, Louisa and Paris, her brother, Matthew, and their families. Her four gorgeous children - Archie, Romilly, Clemmie and Freddie. And Charlie, her husband, whom she described, in a rare bout of objectivity in the book as 'the kindest, funniest, most generous, emotionally intelligent human being in existence, who seems to have been assembled [correctly] from a new-man catalogue, and makes me laugh more than anyone I know'.

She was always able to see so much more than the rest of us, and had always been able to express it so much better, and so much more clearly.

Debs died peacefully last Friday morning. But she leaves her work, her book and her inspiration behind. I wish I had had her book available when my sister, Alice, got cancer. It has helped me so much to talk to Debs and to talk to my other sister, Victoria, who also has cancer.

But her work, her book and her life will help a million more by what it says. It will help Macmillan Cancer Relief by every copy it sells. It will help everyone who faces the challenges she faced.

She has touched the lives of so many. Throughout her life, there was nothing she got her teeth into that she didn't improve and change. The way she dealt with cancer and made it better for other people demonstrated that to a wider world.

But she had been demonstrating those talents to her family and friends all her life.

· Charles Falconer is Lord Chancellor and Secretary of State for Constitutional Affairs

Deborah Hutton's book, What Can I Do To Help?, is published by Short Books at £7.99