Increase in disease is down to lifestyle, not pollution
By Jasper Hamill

A FIRM link between living in western-style cities and breast cancer has been established by Scottish scientists undertaking pioneering research in China, a nation in the grip of an "epidemic" of the disease.

China is seen as a model for studying cancer because the number of women diagnosed with the illness is growing as its rural populations move into large cities and adopt the high-fat, sedentary lifestyle of the West.

Although the number of women in China who develop breast cancer is proportionally about half the number of Scottish women with the disease, researchers feel that the numbers will balance out as more and more people in China start to live the kind of unhealthy life already entrenched in Britain.

Professor Ian Kunkler is the scientist from the University of Edinburgh Cancer Research Centre that is leading the Supremo (selective use of postoperative radiotherapy after mastectomy) trial that will examine the effectiveness of radiotherapy treatments in China and Britain, hoping to find a genetic marker to identify women who will respond to the treatment. Radiotherapy is currently given to 70% of women with breast cancer in Britain although there is no clear indication of whether it works for every patient.

He said: "The incidence of breast cancer in China has been rising quite rapidly, particularly in urban areas. In fact, it's becoming an epidemic. There is a significant contribution from the move away from their traditional diet of tofu and rice to a high-fat western diet.

"If you examine China, you can actually see the effect of that lifestyle on the numbers of people with the disease. It's now the commonest cancer in Asia followed by cervical cancer and is particularly aggressive in women under the age of 40. Unfortunately, breast cancer can be seen as an inevitable consequence of a western lifestyle."

China's urban population has grown by around 3% over the last 10 years, but its breast cancer rates in urban areas have shot up by 23%, meaning that incidence of the disease is now 60 women per 100,000 in Shanghai. With a population of 630 million women in the country, any rise in breast cancer has enormous public health implications.

Kunkler expressed his hope that the results of the large-scale trials would lead to better treatments and added: "What we're hoping to find is whether women need to have radiotherapy and if there is a genetic signature for whether they will respond to it. If we do find that there is, then we can enable both Britain and China to make significant cost savings."

In China, as in Scotland, there are several risk behaviours that make a woman more likely to develop breast cancer, although in Scotland, where around 116 per 100,000 women develop breast cancer, the lifestyle is more entrenched.

Firstly, obesity caused by lack of exercise and a high-fat diet increases the risk of cancer. Smoking and drinking alcohol further increase this risk and there is also evidence that women who have few or no children are in more danger than those with many children - which is particularly relevant in China, with its one child per family policy. An ageing population also contributes to numbers, with cancer more prevalent in elderly people.

Predictions for the future make for grim reading, with the number of women predicted to develop breast cancer in Scotland expected to grow by 20% over the next 10 years.

The blame for this increase in cancer is down to lifestyle, not pollution, said Dr Emma Pennery, clinical director of the charity Breast Cancer Care.

She said: "You can traditionally associate cancers with a western style of living. If you look at countries that traditionally had a lower breast cancer rate, like Japan or China, one of the reasons is that their lifestyles are healthier, there were less people overweight because they don't have high-fat diets.

"But that divide between western and eastern diets is getting smaller. If their lifestyle continues to get worse and worse you have to accept that there will be health problems that go alongside that."

The Scottish government said that it "welcomes any initiative aimed at tackling breast cancer". The Chinese researchers collaborating with the University of Edinburgh could not be reached for comment.