Breast cancer risk

At age 85 women stand a one in 11 chance of developing breast cancer Up to 40 the risk is one in 220 From 20 to 30 the risk is one in 2,165 Around 33,000 women in the UK develop breast cancer each year More than 14,000 deaths each year

Most also said surgery had no impact on sexual relationships, emotional stability or stress levels.

A majority of the women also said they worried less about developing breast cancer and that they would likely make the same choice again.

However, the survey did find that one in five of the patients were dissatisfied or very dissatisfied - most often because of adverse symptoms or complications.

Breast cancer affects about one woman in every nine in the UK.

Up to 10% of cases occur in women with an inherited risk.

The study, published in this week's Journal of the American Medical Association, is related to one released more than a year ago, based on the same group of women, which found that preventive mastectomy was 90% effective for women facing a moderate to high risk for the disease.

Significant findings

My personal experience is that considerable numbers of women who opt for prophylactic mastectomy end up running into problems

Dr James MacKay, Cancer Research Campaign

Lead researcher Marlene Frost said: "These new findings are significant in that they provide needed social and psychological information for women considering a prophylactic mastectomy, enabling them to make more informed decisions about the procedure."

Delyth Morgan, Chief Executive, Breakthrough Breast Cancer said the decision to have a prophylactic mastectomy was a very personal and difficult one.

She told BBC News Online: "This is an interesting study. But we need to know how many women are taking this option each year so that we can support them appropriately and provide the necessary follow-up."

However, Dr James MacKay, a Cancer Research Campaign specialist working at Addenbrooke's Hospital in Cambridge, said the women who took part in the study might not be representative of the population as a whole.

He said they were more likely to be self-motivated, driven individuals, and that more vulnerable people were likely to have refused to take part.

Dr MacKay told BBC News Online: "My personal experience is that considerable numbers of women who opt for prophylactic mastectomy end up running into problems, either with psychological adjustment or with relationships."

Dr MacKay said prophylactic mastectomy was a sensible option for some women, but should only be offered by experts.

"This operation is being done all over the place, and nobody is evaluating it or following it up to see whether people are running into trouble."

Long-term follow up

The women in the study underwent the procedure between 1960 and 1993.

On average, they were asked about how they had coped more than ten years after surgery.

Only 9% to 17% of women who express an interest in prophylactic surgery actually end up going ahead with it.

Most of the women in the study had a subcutaneous mastectomy in which the nipple is left in place, for reconstruction purposes.

Today most women electing to undergo the preventive surgery would have a total mastectomy, in which the entire breast is removed.

However, this has been balanced by advances in surgical reconstruction techniques.

Alternatives to prophylactic mastectomy include regular screening.

Dr MacKay is also conducting trials into the effectiveness of giving women at risk drugs which lower levels of the female sex hormone oestrogen, thought to be linked to breast cancer.