Monday 18 February 2019

Where does cancer come from? We must talk about preventable risk

Most people know about the link between smoking and cancer but few are aware of the other major and controllable lifestyle factors

Although my patient constantly and laughingly referred to himself as a “vegetable”, I never got used to it. I cringed at the expression, often wondering how he really felt beneath the smiles. Short in height and morbidly obese, he hated moving and told everyone how much he loved fat and sugar, preferably together. The first time I met him he struggled to walk the few metres to my room before crashing into a chair and clutching its sides as he regained his breath. He was only 57 years old.

Just before starting chemotherapy he developed a urine infection. His symptoms settled quickly but even I was surprised at the way he became deconditioned. Previously able to get to the bathroom, now he would collapse in bed with each attempt to get up. Then he developed a hospital-acquired pneumonia and nearly died. It was assumed that cancer caused his deterioration, but the real culprit was his dismal lack of fitness. Ultimately, I witnessed my patient’s treatment, and then his life, compromised by habits encompassed by the benign-sounding term “lifestyle factors”. Unfortunately he was neither the first nor the last patient of this kind.

Recently,  to a growing body of evidence that a large proportion of cancers are preventable. The researchers studied known groups of cancer risk factors including smoking, diet, weight, physical inactivity and infections such as hepatitis C and human papillomavirus and estimated that of the 44,000 cancer deaths annually in Australia, 17,000, or nearly 40%, are potentially preventable. This figure mirrors those stated by Cancer Research UK, the American Cancer Society and the World Health Organisation.

‘It’s tricky at the best of times to tell someone to lose weight or drink less but it’s
even harder to tell a patient that a cancer diagnosis might have been preventable if
not for a host of lifestyle decisions’ Photograph: Mark Bowden/Getty Images/iStockphoto
Reflecting on the “untold grief and heartache” that cancer causes, the researchers remind us that even small improvements in our lifestyle have the capacity to translate into important health gains. On current trend, one in two people will be diagnosed with cancer by age 85. To reduce this risk, they suggest we make better dietary choices, eat a little less, move a little more, don’t smoke, curb drinking, and lose some weight. They’re right, of course. The frustration lies in seeing knowledge translated into action.

Every cancer clinic is witness to the end result of a series of lifestyle choices gone wrong. The middle-aged truck driver with lung cancer who has spent 20 years on the roads, with cigarettes, soft drinks and fast food for company. The obese, sedentary office worker suddenly diagnosed with advanced bowel cancer. The scores of men and women with obesity, emphysema, diabetes, heart and kidney disease, before facing cancer as a final insult. Everyone seems surprised that these chronic health conditions can imperil just as much as cancer.

Listening to patients provides insights into how their lifestyle came to be so. Some people can’t afford the cost premium of fresh fruit and vegetables and their living or working conditions make regular exercise difficult, if not impossible. Some people smoke because that’s what their whole family does. They drink because to refrain would be considered abnormal among their friends. Everyone in their family is on the large side, so they haven’t thought of themselves as overweight.

Smoking impairs response to cancer treatment. Obesity increases recurrence risk. Lack of fitness portends hazardous complications. Poor diet hampers immunity. There is common awareness of the link between smoking and cancer but few people are aware of the other major and controllable risk factors. Mostly, they think that cancer happens due to bad luck and bad genes.

Oncologists are no strangers to the plentiful associations between lifestyle and cancer but while I have no illusions about changing human nature in the course of a few appointments, it never fails to strike me how seldom we broach lifestyle. For one, it’s easier to prescribe chemotherapy than to counsel patients about their habits. In the short time available, it is expedient to stick to the necessary conversations which tend to be about diagnosis and management. It is increasingly challenging to adopt a long-term and holistic view of the person behind the cancer but this shortcoming undoubtedly hurts patients.

Giving chemotherapy is the easy part. Linking a patient into accessible, publicly funded, sustainable harm reduction programs, whether related to diet, exercise, smoking, drugs or alcohol is surprisingly difficult. There is enormous geographic and socioeconomic variation in access to such services – the employed executive with generous leave arrangements can find several options within easy reach but things aren’t so easy for the unemployed single mother who is also the carer for her disabled son. She is much more likely to retain all the factors that led to cancer development in the first place that will now claim her life.

One might ask if we shouldn’t take personal responsibility for getting healthy but recidivism rates are high because poor health habits are addictive and people need more structured help than simply being told to quit. The result of gaps in public health policy is a failure of primary prevention that leads to expensive hospital-based care, which is ill-equipped to change long-term health indicators.

When it comes to communicating risk, cancer occupies a unique and unfortunate space. Societies are aware about the dangers of unprotected sex. Mothers know why childhood vaccination matters. Public transport carries the warning features of a stroke. But the origin of cancer remains shrouded in mystery even as researchers peel back the layers.

It’s tricky at the best of times to tell someone to lose weight or drink less but it’s even harder to tell a patient that a cancer diagnosis might have been preventable if not for a host of lifestyle decisions. By sidestepping a conversation about risk factors we miss an important opportunity for educating the patient, concerned relatives and the broader community.

The conversation about cancer has always been framed as a battle. With its powerful imagery of productive lives laid to ruin cancer evokes fear, powerlessness and devastation like none else. It is widely perceived as a mysterious, insidious, and ultimately hopeless condition. For a disease where the patient never feels in charge, what the Australian researchers provide us is hope. Hope that knowing the risk factors is a step towards modifying them. Hope that like other diseases we have demystified, there are things we can do to prevent cancer.

While some of us have heard of someone who never smoked or drank, ran marathons and still got cancer, we all know someone who was obese or smoked or drank excessively who got cancer. Everyone deserves our sympathy and understanding but it would be even better if their experiences taught us something. A striking proportion of cancers are preventable. We ought to be grateful to the Australian researchers for showing us the way.

(Source: The Guardian)

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