Abstract
BACKGROUND: The reasons for variation in survival in breast cancer are multifactorial. METHODS: From 1999 to 2003, the vital status of 9051 cases of invasive breast cancer was identified in the Eastern Region of England. Survival analysis was by Cox proportional hazards regression. Data were analysed separately for patients aged <70 years and those older due to differences in treatment policies. RESULTS: Overall 5-year survival was 78%. In patients aged <70 years, significant differences in survival lost their formal significance after adjustment for detection mode and node status, although this remained close to statistical significance with some residual differences between relative hazards. There was significant negative ecological correlation between proportion with nodes positive or not examined and 9-year survival rates. Patients with estrogen receptor (ER) status unknown were at significantly higher risk of dying than ER-positive patients. There was a clear trend of increasing hazard of dying with increasing deprivation. Survival differences in women aged > or =70 years were related to whether surgery was included as part of treatment. CONCLUSION: This variation in treatment and survival may be attributed to lack of information, in particular nodal and ER status, thereby impacting on staging and prescription of adjuvant therapy.