The proportion of women who survive breast cancer has improved dramatically since the 1990s, say researchers, who found, in the largest study of its kind, that 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”.
The 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, which dropped to just 4.9% for women diagnosed between 2010 and 2015.
The findings, published in The BMJ, also showed that for some women, the risk of death within five years was as low as 0.2%, reports The Guardian.
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, mostly examining cases where the 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.
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.
“In the future, further research may be able to reduce, even more, the death rates for women diagnosed with early breast cancer.”
Some reasons for 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 them and their cancer.
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.
Study details
Breast cancer mortality in 500 000 women with early invasive breast cancer in England, 1993-2015: population based observational cohort study
Carolyn Taylor, Paul McGale, Jake Probert, John Broggio, Jackie Charman, Sarah Darby, Amanda Kerr, Timothy Whelan, David Cutter, Gurdeep Mannu, David Dodwell.
Published in The BMJ on 13 June 2023
Abstract
Objectives
To describe long term breast cancer mortality among women with a diagnosis of breast cancer in the past and estimate absolute breast cancer mortality risks for groups of patients with a recent diagnosis.
Design
Population based observational cohort study.
Setting
Routinely collected data from the National Cancer Registration and Analysis Service.
Participants
All 512 447 women registered with early invasive breast cancer (involving only breast and possibly axillary nodes) in England during January 1993 to December 2015, with follow-up to December 2020.
Main outcome measures
Annual breast cancer mortality rates and cumulative risks by time since diagnosis, calendar period of diagnosis, and nine characteristics of patients and tumours.
Results
For women with a diagnosis made within each of the calendar periods 1993-99, 2000-04, 2005-09, and 2010-15, the crude annual breast cancer mortality rate was highest during the five years after diagnosis and then declined. For any given time since diagnosis, crude annual breast cancer mortality rates and risks decreased with increasing calendar period. Crude five-year breast cancer mortality risk was 14.4% (95% confidence interval 14.2% to 14.6%) for women with a diagnosis made during 1993-99 and 4.9% (4.8% to 5.0%) for women with a diagnosis made during 2010-15. Adjusted annual breast cancer mortality rates also decreased with increasing calendar period in nearly every patient group, by a factor of about three in oestrogen receptor positive disease and about two in oestrogen receptor negative disease. Considering just the women with a diagnosis made during 2010-15, cumulative five-year breast cancer mortality risk varied substantially between women with different characteristics: it was <3% for 62.8% (96 085/153 006) of women but ≥20% for 4.6% (6962/153 006) of women.
Conclusions
These five-year breast cancer mortality risks for patients with a recent diagnosis may be used to estimate breast cancer mortality risks for patients today. The prognosis for women with early invasive breast cancer has improved substantially since the 1990s. Most can expect to become long term cancer survivors, although for a few the risk remains appreciable.
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