A third of all cancers in the UK are potentially preventable, finds reviewBMJ 2011; 343 doi: http://dx.doi.org/10.1136/bmj.d7999 (Published 07 December 2011) Cite this as: BMJ 2011;343:d7999
A third (more than 100 000 cases) of all cancers in the United Kingdom are caused by just four risk factors and are potentially preventable, concludes a comprehensive review of the evidence.
The researchers estimated that 106 845 cancers in the UK in 2010 were associated with smoking, poor diet, alcohol, and excess weight. And when all 14 lifestyle and environmental risk factors were included, this figure rose to 134 000 or (43% of the total).
The review, published as a supplement in the British Journal of Cancer (http://info.cancerresearchuk.org/groups/cr_common/@nre/@new/@pre/documents/generalcontent/cr_080626.pdf), found that 45% of all cancers in men and 40% in women could be prevented. The review looked at all the available evidence together with the latest (2010) estimates of cancer incidence.
The study’s lead author, Max Parkin, a Cancer Research UK epidemiologist who is based at Queen Mary college, University of London, said, “Leading a healthy lifestyle won’t guarantee you won’t get cancer, but doing so can greatly stack up the odds in your favour.” He added: “Nine out of 10 lung cancer cases can be prevented. Half of all colorectal cancers are due to the main four risk factors.”
The most important lifestyle risk factor for men and for women is smoking—causing 23% of cancers in men and 15.6% in women. Harpal Kumar, chief executive of the Cancer Research Campaign, said, “Smoking is still the biggest priority to tackle in terms of cancer prevention. The rates did come down substantially but have now plateaued, so we need to do much more. We need to get the message across that smoking is not just a risk factor for lung cancer but other cancers too.”
For women, being overweight was shown to have a greater effect than drinking alcohol. The percentage of cancers in women linked to overweight and obesity was 6.9%, double the 3.3% for alcohol. “Being overweight is a clear risk factor for breast cancer, and because breast cancer is so common, that makes it higher in the ranking,” said Professor Parkin. Infections such as human papillomavirus were linked to 3.7% of cancers in women, excessive sun exposure and sunbeds to 3.6%, and lack of fruit and vegetables to 3.4%.
For men, the next biggest risk factor, after smoking, was a lack of fruit and vegetables, at 6.1%. Occupational risks, such as exposure to asbestos, was linked to 4.9% of cancers in men. Alcohol was linked to 4.6% of cancers and being overweight or obese to 4.1%.
“Like most healthcare systems in the world we focus a disproportionate amount on treatment rather than prevention,’ said Dr Kumar. “If we could prevent 134 000 cases of cancer a year that would be an enormous saving for the NHS.”
In a foreword to the report, Richard Peto, a leading expert on deaths attributable to tobacco, writes, “Each of these four main strategies for cancer control would also substantially reduce the burden of other non-communicable diseases, particularly cardiovascular, diabetic, renal, and hepatic disease.”
Professor Peto concludes: “This supplement will help focus the attention of researchers, individuals, and policy makers on the relative importance of the currently known causes of cancer.”
Cite this as: BMJ 2011;343:d7999