If they were diagnosed at the same stage as those who lived in affluent areas, hundreds of women with breast cancer living in England's most deprived areas would have better survival rates.
A new study led by the University of Leicester, working with colleagues from Public Health England and the University of Cambridge, investigated how much of a difference late-stage diagnosis had on women from deprived areas.
The team calculated how many deaths would be postponed beyond 5 years from diagnosis if as many women in the more deprived areas were diagnosed at an earlier stage as those in most affluent areas.
The research team consisted of:
At the University of Leicester, Department of Health Sciences: Dr Mark Rutherford, Sally Hinchliffe and Professor Paul Lambert.
At the University of Cambridge, Centre for Health Services Research, Institute of Public Health: Dr Gary Abel, Dr Georgios Lyratzopoulos and Dr David Greenberg.
Dr Mark Rutherford, of the Department of Health Sciences at the University of Leicester, said: "A number of previous studies have shown poorer breast cancer survival for women who live in more deprived areas. Our study looks at how much of these differences are due to later stage disease at diagnosis for women who live in more deprived areas."
"We found that for a typical yearly cohort of breast cancer patients in England, 450 deaths could have been postponed beyond 5 years of diagnosis if the stage distribution for all women matched that of the most affluent."
The teams from the University of Leicester and University of Cambridge used data from the Eastern Cancer Registry who have good information on stage at diagnosis, but made some assumptions when estimating figures for the whole of England.
Dr Rutherford added: "Our research highlights that important and significant improvements could be made in terms of the number of early deaths that are observed for women living in more deprived areas by concentrating on making sure these women are diagnosed earlier."
"The findings suggest that policies aimed at reducing inequalities in stage at diagnosis between women with breast cancer are important to reduce inequalities in breast cancer survival."
"Being diagnosed with earlier stage disease has a significant impact on survival chances. It is clear from the results of the study that women from more deprived areas are more likely to be diagnosed with advanced stage disease. Removing these deprivation inequalities in stage at diagnosis can substantially reduce the number of deaths in the short-term for more deprived women."
Dr Martine Bomb, head of early diagnosis at Cancer Research UK, said: "There is already good evidence that breast cancer survival is poorer among more deprived women, and this research helps us understand more about why that might be. More needs to be done to tackle this inequality to ensure everyone has the same chance of surviving breast cancer, no matter where they live."
"Cancer Research UK is working in partnership with others to help people get to know their bodies, know what signs to look out for that could be cancer and see their doctor sooner rather than later if they have noticed something out of the ordinary. Spotting breast cancer at an early stage makes a real difference to women's chance of surviving the disease, and we must ensure this is a reality for all."