A link between poverty and the mutation of a gene may be the reason women from poor backgrounds are less likely to survive breast cancer, according to new research.
Scientists at the University of Dundee compared survival rates from the cancer with a patient's socio-economic status.
They also looked at the number of the p53 breast cancer mutation - a change which reduces the body's ability to suppress tumours.
The study, published this month in the British Journal of Cancer, found women in the lowest socio-economic groups were "significantly more likely" to have a relapse and die from breast cancer compared with those in more affluent categories.
The survey, funded by Breast Cancer Research Scotland and the Tayside Tissue Bank, looked at a total of 246 women who underwent treatment for breast cancer between 1997 and 2001.
Researchers examined frozen tissue and carried out tests to determine the p53 mutation status.
The patients' postcodes were used to calculate a "deprivation score" for each and compared whether they made a full recovery from the disease, suffered a relapse or died.
Results suggested the p53 mutation was associated with the worst survival rate and shorter disease-free interval in breast cancer.
Women from deprived backgrounds were more likely to experience a mutation of p53, and this linked to higher relapse and mortality rates, the study found.
Doctor Lee Baker, of the Department of Surgery and Molecular Oncology at the University of Dundee, said smoking, drinking and poor diet were more common in women from lower socio-economic groups, who are also more likely to experience a recurrence of the disease and to die as a result of breast cancer.