Researchers found that carrying out a lumpectomy - removing just the diseased tissue - could save as many lives as a total breast removal in women with small tumours.

The results confirm data from the 1970s and 1980s which showed that mastectomies were often unnecessary.

But some doctors had predicted that the less radical treatment would, over the long term cause more deaths.

Radical

This was why at least 29% of women who were eligible for the less radical treatments were not told about them by their doctors.

Over 50,000 breast cancer operations were performed in England in 2000-2001 and 15,000 of theses involved mastectomies.

It is time to declare the case against breast-conserving therapy closed and focus our efforts on new strategies for the prevention and cure of breast cancer

Dr Monica Morrow

The study, published in the New England Journal of Medicine, was carried out by the University of Pittsburgh and Italy's European Institute of Oncology and studied more than 2,500 women.

Dr Monica Morrow, a breast cancer specialist said the findings had been quite conclusive and should convince " even the most determined sceptics that mastectomy is not superior to breast conservation."

In an editorial Dr Morrow said doctors must now focus on a cure for breast cancer.

Survival

"It is time to declare the case against breast-conserving therapy closed and focus our efforts on new strategies for the prevention and cure of breast cancer."

Both studies showed that whether they had a lumpectomy or mastectomy the women had similar chances of survival.

Researchers in Italy studied 701 women over two decades and found that a quarter of both groups died from breast cancer.

Small tumours can be treated by lumpectomies

The US researchers also found little survival differences between the 1,851 women they studied.

They said that this is because breast cancer is fundamentally systemic and not one that simply spreads from an initial site.

Breast-conserving surgery is therefore the treatment of choice for women with relatively small breast cancers

Dr Umberto Veronesi

Dr Umberto Veronesi of the European Institute of Oncology in Milan said women with small tumours should have breast-conserving surgery.

"Breast-conserving surgery is therefore the treatment of choice for women with relatively small breast cancers.

"These results should dispel any lingering doubts about the safety and efficacy of breast-conserving surgery as a treatment for breast cancer."

Choice

Delyth Morgan, chief executive of the charity Breakthrough Breast Cancer, told the BBC that the new research underlined the importance of choice for women and added that British surgeons had been advocating breast-conserving surgery for years.

"In this country the tradition is very much for breast reconstruction and breast conservation surgery so what this is doing is it should be reassuring us thta we are doing the right thing."

But she stressed that in some cases mastectomy was still the best option for some women.