Prognostic factors in women with breast cancer: distribution by socioeconomic status and effect on differences in survival

Study objective-To quantify and investigate differences in survival from br east cancer between women resident in affluent and deprived areas and defin e the contribution of underlying factors to this variation. Design-Analysis of two datasets relating to breast cancer patients in Scotl and: (1) population-based cancer registry data; (2) a subset of cancer regi stration records supplemented by abstraction of prognostic variables (stage , node status, tumour size, oestrogen receptor (ER) status, type of surgery , use of radiotherapy and use of adjuvant systemic therapy) from medical re cords. Setting-Scotland. Patients-(1) Cancer registration data on 21 751 women aged under 85 years d iagnosed with primary breast cancer between 1978 and 1987; (2) national cli nical audit data on 2035 women aged under 85 years diagnosed with primary b reast cancer during 1987 for whom adequate medical records were available. Main results-Survival differences of 10% between affluent and deprived wome n were observed in both datasets, across all age groups. In the audit datas et, the distribution of ER status varied by deprivation group (65% ER posit ive in affluent group v 48% ER positive in deprived group; under 65 age gro up). Women aged under 65 with non-metastatic disease were more likely to ha ve breast conservation than a mastectomy if they were affluent (45%) than d eprived (32%); the affluent were more likely to receive endocrine therapy ( 65%) than the deprived (50%). However, these factors accounted for about 20 % of the observed difference in survival between women resident in affluent and deprived areas. Conclusions-Deprived women with breast cancer have poorer outcomes than aff luent women. This can only partly be explained by deprived women having mor e ER negative tumours than affluent women. Further research is required to identify other reasons for poorer outcomes in deprived women, with a view t o reducing these survival differences.