A 50-year study of breast cancer was launched yesterday to find new ways to prevent one of the major killers of women.

A 50-year study of breast cancer was launched yesterday to find new ways to prevent one of the major killers of women.

Researchers aim to recruit 100,000 British women aged from 18 to 79, who will be studied over the course of their lives for factors affecting their risk of the disease.

It is the largest study ever launched with a specific focus on breast cancer and is backed by the charity Breakthrough Breast Cancer. It is supported - like most initiatives in this field - by a bevy of celebrities, including the former EastEnders actress Michelle Collins, the television newsreaders Fiona Bruce and Katie Derham and the well-known socialite Tara Palmer-Tomkinson.

About 40,000 women a year develop breast cancer in the UK and 13,000 die. Although the death rate has fallen in recent years thanks to improved treatments, the incidence of the disease is rising. Researchers believe that at least 30 per cent of cases of breast cancer - 10,000 to 15,000 a year - could be prevented by giving advice to women on how to reduce their risk if the causes of the disease were better understood.

Professor Anthony Swerdlow of the Institute of Cancer Research, one of the leaders of the study, said: "Breast cancer has causes that go back decades. If you want to get to the bottom of it you need to follow people from as young an age as possible to as old as possible. A study with a 30, 40 or 50-year follow-up is probably the key to this."

The researchers cite the wide difference in risk between Japanese women living in Japan, who have low rates of breast cancer, and Japanese women who emigrate to the United States, who have levels two to three times higher. The difference suggests environmental causes, probably related to changes in diet once women move to the US.

Breakthrough Breast Cancer aims to raise £12m to pay for the first 10 years of the study, including the cost of buying 7.2 million tubes to store the blood samples collected. The Institute of Cancer Research is to raise a further £5m.

Any woman in Britain can take part in the study, known as the Breakthrough Generations Study, and the researchers are especially looking for related women, including adult sisters, daughters and mothers, to study the interaction between genetic and environmental factors.

Blood samples will be taken every five years and the women will be asked to fill in questionnaires about their lifestyle to provide the most detailed information yet on the potential causes of the disease.

Few studies involving the collection of blood samples have exceeded 60,000 women, and bigger studies have been multipurpose, investigating several diseases.

Women interested in joining the study can telephone 0870 242 4485 or visit the website at breakthroughgenerations.org.uk