Women who take the Pill for long periods of time could be more than doubling their risk of getting breast cancer. A major new study of more than 100,000 women shows that taking oral contraceptives for many years is linked to a higher risk of breast cancer than previously thought. The research - one of the largest studies on oral contraceptives - revealed that women who have ever taken the Pill are 26 per cent more likely to develop breast cancer than those who have never used the contraceptive. Women who were taking the Pill in their 30s and 40s were 58 per cent more likely to develop the disease than those who had never used it. And among women who continued to take the Pill at 45 and over, the risk of breast cancer more than doubled. These women had a 144 per cent increased risk, which means they were almost one and a-half times more likely to develop breast cancer than non-users. Dr Merethe Kumle, the Norwegian epidemiologist who carried out the research, estimates that the Pill could be responsible for one in 20 cases of breast cancer among women in their late 40s. The findings, presented yesterday at the Third European Breast Cancer Conference in Barcelona, will raise fresh concerns about the Pill. They will be of particular concern to the thousands of women who are using oral contraceptives for long periods while they concentrate on building up their careers. The Pill is the most effective form of contraception and is the preferred method of family planning for women who want to delay childbirth until their 30s and 40s and those women who decide not to have children at all. Latest official figures show that 43 per cent of women in their late 20s and 32 per cent of women aged 30 to 34 take the Pill. By the age of 40, ten per cent of women are taking the drug. Last night, campaigners described the findings as 'extremely alarming'. Rachel Heath, from the charity Life, said: 'This is important research and extremely alarming. We have always known that the Pill has an influence on breast cancer, but this research is highly significant, particularly for older women who are delaying childbirth to get their careers underway. 'It needs to be taken very seriously and women need to be warned. This is a serious risk and women need to consider whether staying on the Pill for as long as they are at the moment is going to harm their health.'