The breast specialist
Tena Walters, 51, consultant, London Breast Clinic
Just this week the papers splashed on another piece of research criticising breast cancer screening, saying that for every woman saved by the procedure, up to 10 have been treated unnecessarily. This sort of coverage is a constant annoyance. The evidence just doesn't stack up. I've worked as a breast surgeon for 16 years, and have been having mammograms myself since I was 44, six years younger than the NHS breast cancer screening programme stipulates. To my mind, it is still the strongest preventative measure one can take, and dealing with the disease on a daily basis means I'm lucid with the statistical risks: one in 250 for 40-year-olds, one in 50 for 47-year-olds and, roughly, a one-in-10 lifetime risk.
I nip down to the radiographer once every year, in a spare five minutes, to get it done. It's always on my birthday, so I don't forget. I don't particularly enjoy it, as it can be awkward exposing yourself, especially to people you work with, but you get over it.
Despite coming into contact with the disease on a daily basis, much of my job is about reassuring women they can be successfully treated – I'm often with them through most of their treatment, from diagnosis to chemotherapy and carrying out surgery. Many clinicians working in the field will tell you to do all things in moderation; I abide by this, but also think moderation itself should be done moderately, too. While I lead a generally healthy lifestyle, I drink a glass of wine three nights a week, even though I know it enhances the risk of contracting the disease. I don't live my life in a constant state of paranoia.
One of the most vivid memories I have of my training is caring for an 18-year-old boy dying of leukaemia. There was nothing he should or could have done to stop it. It was then that I was struck by how much of life is a lottery.
The tumour specialist
Kairbaan Hodivala-Dilke, 45, professor of angiogenesis, Queen Mary University, London
It's factor 50 and no less for anyone in my family, and I am obsessive about it. When I see other people's children charging about in the sun without sunblock on, I think they're mad. Even if my two are out for less than an hour, I make sure they're caked in the stuff. My husband is a bluey-skinned, caucasian type – poor him – and absolutely hates wearing it, but when we're visiting family abroad, I can't deal with him unless he's got it slapped on.
At Queen Mary I study how blood vessels grow into cancers. I see the different ways cancer forms and is fed on a daily basis. Of course, I'm viewing it at work, inside a petri dish and through a microscope, but watching it every day makes me acutely aware of any lumps or bumps I see on anyone.
I have known since the age of 14 that I wanted to work in cancer research. My neighbour died of a brain tumour, and seeing the three small children she left behind inspired me to make a change. We're at the stage now, with certain experiments in my lab, where, at a very basic level, we can control cancer growth. There's not really a way to describe how exciting the work can be.
A family friend was recently diagnosed with breast cancer, and is convinced asparagus juice is going to save her. I am unpersuaded. Working as I do in controlled, rigorous research, the constant flow of reports I see presenting new prevention methods, is something I take with a pinch of salt.
The advice I constantly give to friends and family is that if you notice anything untoward, seek expert opinions as quickly as possible.
The neurologist
Peter Rothwell, 47, professor of clinical neurology, University of Oxford and John Radcliffe hospital
I wake early, about 6am, come downstairs, tend to our three young children, then pop my daily low-dose aspirin, doing it on an empty stomach (which isn't recommended, of course), as I don't take breakfast. It has been a routine since my research into the effects of aspirin on cancer prevention really started getting interesting, around three years ago.
We had already shown, in 2007, that taking a high-dose aspirin on a daily basis for about five years reduced the long-term risk of contracting colon cancer by about 50%, but around 2009 we began to show that a low-dose pill had the same effect, as well as significantly reducing the chance of other cancers, including oesophageal.
Most of my research is clinical, but the aspirin work has been mainly paper-based, and over the years I've trawled the archives of many old trials from the 1980s onwards that looked at the effect of a daily aspirin on the risk of stroke and heart attack. We spent hundreds of hours looking through thousands of dusty case notes, extracting information on cancers. It's a lengthy process, and has also required us to trace what happened to participants after the trials finished, to see if they developed cancer subsequently.
Ironically, it has probably not helped my own health, as I conducted the work outside my day job, in spare evenings and weekends, without any funding, and completely stopped exercising because of it.
Having access to the information on people's struggles against cancer has been a great privilege. One of the trials we studied was Sir Richard Doll's British Doctors Trial, where all participants were clinicians themselves, and several were researchers I had admired and revered over the years. It's so important for researchers who advise the public to participate in research or to adopt a particular lifestyle to be willing to do the same themselves. If we don't practise what we preach, we lose a degree of our credibility.
The prostate specialist
Jonathan Waxman, 49, professor of oncology, Imperial College London and Hammersmith hospital
There are established studies that argue vegetarians are 50% less likely to contract certain common cancers than carnivores. Having flirted with vegetarianism at various stages of my life, I eventually gave up 15 years ago – nothing is better than a well-roasted chicken.
I am an oncologist specialising in prostate cancer, and in the early 1980s discovered a pioneering form of medical treatment for the disease, which until then was treated with surgical castration to cut hormone production. It is said a Mediterranean-style diet can be an important preventative tool against cancer of the prostate – eating lots of processed tomato products and olive oil. I do both, predominantly for their taste, and keep a keen eye on my weight.
It is my emotional lifestyle that has changed enormously as a result of working with cancer. Witnessing the effects of such a destructive disease over such a long period has meant locking your emotions away in a freezer, hardly being able to feel any more. I lost my father to cancer, and it was only years later that I came to terms with it. Letting my emotional guard down while discussing it with friends, it finally hit me. Before, I had simply glossed over the pain of my loss.
Cancer is at the forefront of my mind all the time, not simply because of work, but because I fear contracting it. In that respect, it influences my consumption of the things around me. I'm no profligate, so it means appreciating the day, sniffing the air, enjoying the sunshine, treasuring the moment. I love what is around me more as a result of this most deadly disease.
The colorectal specialist
Robert Steele, 60, professor of surgery, Ninewells hospital, University of Dundee
Over the decades spent working in oncology I've made a number of changes to my life. I gave up smoking as a junior doctor while working on a respiratory ward and seeing so many lung cancer patients, I started taking vitamin D tablets after reading research linking a deficiency (of which there is much in Scotland due to the lack of sunlight) to certain types of cancer, and have always watched my weight.
These have all been relatively painless. But in 2007, after attending the launch of the most compelling research I have read into lifestyle choices and cancer, I decided to temper my intake of red meat. As director of the Scottish colorectal cancer screening programme, I was aware of the links between excessive red and cured meat consumption with this and other forms of cancer, yet I still ate one meal a day that contained it.
I'm now down to about twice a week, and have almost completely cut out cured meat. Reneging on bacon rolls has been difficult, but I know that twice a year – new year's day and my birthday – my wife, herself a nutritionist, will cook me them as a treat. It's something to look forward to, at least.
Seeing and operating on colorectal cancers regularly is a powerful stimulus – they don't look pretty at all. But I'm not in the business of telling people certain things should be banned completely. Nor am I one to dismiss leftfield practices outright. As well as surgery and screening, I have research interests in prevention, and have seen projects on all manner of quirky methods. If people wish to use homeopathic medicine in an attempt to prevent cancer, despite there being no medical evidence for its success or any active component whatsoever, the placebo effect itself may be strong.
The lung specialist
Adam Dangoor, 42 medical oncologist, University Hospital Bristol
A while ago I was approached by a teenager outside our local grocery shop. She asked me to buy her some fags, and I had to tell her she'd asked the wrong person. I am a medical oncologist specialising in the treatment of lung cancer; seeing people smoking as young as that is a constant frustration.
Of the lung-cancer patients I deal with, around 90% of them are smokers. Fortunately, I have never taken it up. My mother was a nurse, and when you start your medical training, as a teenager in my case, meeting patients with serious illnesses, it makes you consider your own mortality and think twice about engaging in risky habits.
I recall sharing a flat with smokers a few years back, and was amused at the contradictions in their lifestyles: I'd see one go out and enjoy a heavy night of social smoking and then wake up the next morning and eat a bio-yogurt for the health benefits he thought it would provide. Going out with them could be uncomfortable; before the smoking ban, I'd sit in pubs and sometimes have to leave early as their smoke stung my eyes.
On occasion, I'll have to tell three or four people in a day they've got months to live. It's a difficult part of the job. I try not to take my work home with me or let it affect me too much, but to really empathise with your patients you have to try to see things through their eyes. If I treat someone close to my age with young children, like me, it's hard not to think about it later.
It's not uncommon to have patients approach me, clutching the latest Daily Express front cover, demanding treatment they've seen reported in the tabloids. It can be difficult to explain there's not yet sufficient evidence for offering it – and in some cases no evidence at all.
Ultimately, however, oncology is a hugely satisfying speciality. Whether it be about prolonging life, relieving pain or psychologically supporting a patient and their family through illness, I find what I do hugely rewarding.