Women diagnosed with early breast cancer are 66% less likely to die from the disease than they were 20 years ago, and most can expect to become “long-term survivors”, according to the largest study of its kind.

Research from the University of Oxford reveals that the risk of death within five years of diagnosis was 14.4% for women diagnosed between 1993 and 1999.

This fell to 4.9% for women diagnosed between 2010 and 2015, according to the findings published in the BMJ.

For some women the risk of death within five years is as low as 0.2%, according to the large-scale research.

The proportion of women who survive the disease has improved substantially since the 1990s, experts found.

Cancer Research UK, which funded the study, said the figures were “heartwarming” and would come as reassuring news to women with breast cancer.

Researchers, led by academics at the University of Oxford, tracked survival rates in half a million women diagnosed with breast cancer in England between 1993 and 2015.

The authors mostly examined cases where breast cancer had not spread beyond the breast.

They then tracked the cases to assess their risk of death five years after their diagnosis – when the risk of death from breast cancer was found to be highest.

“The prognosis for women diagnosed with early invasive breast cancer has improved substantially since the 1990s,” the authors wrote.

“Most can expect to be long-term cancer survivors.”

Dr Carolyn Taylor, a professor of oncology at Oxford Population Health and lead author of the paper, said: “Our study is good news for the overwhelming majority of women diagnosed with early breast cancer today because their prognosis has improved so much.

“Their risk of dying from their breast cancer in the first five years after diagnosis is now 5%.

“It can also be used to estimate risk for individual women in the clinic. Our study shows that prognosis after a diagnosis of early breast cancer varies widely, but patients and clinicians can use these results to predict accurate prognosis moving forward.

“In the future, further research may be able to reduce the breast cancer death rates for women diagnosed with early breast cancer even more.”

Some of the potential drivers in the improvement in survival rates could include new treatments, improved radiotherapy, better detection and breast screening and studies which have uncovered varying characteristics of breast cancer, experts said.

Cancer Research UK said this was the first study of this size with an extended follow-up to not only track which women died from their disease, but map out characteristics of the patients and their cancer.

The charity said that meant doctors would be able to use it to provide an accurate prognosis for women.

The paper states that among 15,533 women aged 50 to 70 with “screen-detected cancer that was HER2 negative, oestrogen receptor positive, medium grade, size 1-20 mm, and node negative” the average risk of death in five years was just 0.5%.

And the estimated five-year breast cancer mortality risk for a 60-year-old woman diagnosed with a “screen-detected tumour, (less than) 20mm (in size), low grade, oestrogen receptor positive, HER2 negative, and node negative” would be only 0.2%.

The researchers analysed different characteristics of the disease and found that for 63% of women, the risk of dying within five years was lower than 3%. But for 4.6% of women, the risk was 20% or higher.

Cancer Research UK’s chief executive, Michelle Mitchell, said: “It’s heartwarming news that women today have more time with their families and loved ones after an early breast cancer diagnosis.

“Receiving any cancer diagnosis is an extremely worrying time, but this study can give patients a more accurate prognosis and offer reassurance for many women.

“Through the power of science, research, clinical trials and screening over the last 20 years, huge improvements have been made in cancer diagnosis and treatment. However, the UK lags behind other countries when it comes to cancer survival.

“The governments across the UK must show political leadership in cancer by taking action to help diagnose and treat cancers earlier and ensure the NHS has enough staff and equipment to meet the growing demands of the future.”