Obesity and alcohol linked to record breast cancer cases

Cases of breast cancer in Britain have reached a record high, with the number of women diagnosed with the disease passing the 40,000 mark for the first time.

Experts for the charity Cancer Research UK blamed part of the rise on soaring rates of obesity and increased alcohol consumption. But there is a continuing fall in deaths from the disease because of early detection and better treatment.

Cases of breast cancer rose from 34,441 in 1993 to 40,089 in 1999, the last year for which figures are available. Even when extra cases picked up by the NHS's recent screening programme are taken into account, there has been a real rise in cases. At the same time, deaths from the disease fell from 14,615 in 1993 to 13,019 in 1999.

Professor Jack Cuzick, head of epidemiology at Cancer Research UK, said cases of the disease appeared to be rising by 2 per cent a year, while deaths were falling at the same rate. "The reasons behind the increase in incidence are more complex and we are only just beginning to understand the risk factors," he said. "Rates of obesity are increasing dramatically and there is concern that that may be contributing to the rise in breast cancer. Weight is the new thing we are focusing on."

Professor Cuzick said that for women who were overweight, every kilogram they put on represented a 1 per cent increased risk of breast cancer. So, a woman who is 20kg over her recommended weight is 20 per cent more likely to contract the disease.

One in five women in the UK is classed as obese and a further third is overweight.

The link between obesity and breast cancer is partly because most cases of the disease occur in older women who have gone through the menopause and are more likely to be overweight. After the menopause, the ovaries stop producing oestrogen, the female hormone that also helps cancerous cells in the breast to grow. But fat also produces oestrogen, meaning obese women are at higher risk. Alcohol is another risk factor in breast cancer, although experts are less sure about why it affects rates.

Professor Cuzick said that women who drank two units of alcohol a day were 20 per cent more likely to develop breast cancer than teetotallers. In non-drinkers, by the age of 80, there will be 8.8 cases per 100 women, compared with 10.5 for those who drink.

The proportion of women drinking more than the recommended maximum of 14 alcohol units a week has risen from 10 per cent in 1988 to 15 per cent in 1998. Half of all women drink at least once a week, and 13 per cent have alcohol on five days out of seven.

Experts believe the incidence of breast cancer is also rising because women are waiting longer to have children, as well as having smaller families. Having a child before the age of 30 and having more children protect against the disease.

Scientists are still working to identify the genes that cause breast cancer. They have already pinpointed the BRCA 1 and 2 genes, which, if carried, mean a woman has an almost 50 per cent chance of developing the disease, but these only account for 5 per cent of cases.

"Most of the genetic risk of breast cancer is down to genes which we have yet to understand," Professor Cuzick said. "Lifestyle factors are important and women need to be aware of them, but the biggest risk is family history of the disease."

Researchers are trying to focus on ways of preventing women at high risk of breast cancer from developing it. About 10 per cent of women are considered high risk because of their family history.

A new international trial is being set up to test whether the drug anastrozole, currently used to treat breast cancer, could prevent the disease.

How early detection saved a life

Barbara Gibbs is living proof of the way detection and treatment of breast cancer has improved in the past 20 years. She had no family history of the disease and felt fit and well when called for a routine breast screening in 1997.

"I didn't think anything of it ­ it was just a slight inconvenience," she said. Aged 56 at the time and a mother of adult children, Mrs Gibbs was shocked when the mammogram showed a cancerous tumour. "Within a week I was on the operating table," she said. "It was the most awful shock. The cancer was so deep that it would only have been picked up by the mammogram."

After surgery to remove the lump, Mrs Gibbs, a former flight attendant from Sunningdale, Berkshire, had six months of radiotherapy. She then took a daily dose of tamoxifen for five years, along with regular check-ups. "Now I just see my doctor once a year," she said. "Waiting for the diagnosis and treatment was hell, but life is great now ... I would say to any woman, just go for the screening, however inconvenient, because it could save your life."