Survival from breast cancer: an analysis of Australian data by surgeon case load, treatment centre location, and health insurance status

Abstract

OBJECTIVE: Early invasive breast cancer data from the Australian National Breast Cancer Audit were used to compare case fatality by surgeon case load, treatment centre location and health insurance status. METHOD: Deaths were traced to 31 December 2007, for cancers diagnosed in 1998–2005. Risk of breast cancer death was compared using Cox proportional hazards regression. RESULTS: When adjustment was made for age and clinical risk factors: (i) the relative risk of breast cancer death (95% confidence limit) was lower whensurgeons’ annual case loads exceeded 20 cases, at 0.87 (0.76, 0.995) for 21–100 cases and 0.83 (0.72, 0.97) for higher case loads. These relative risks were not statistically significant when also adjusting for treatment centre location (P_0.15); and (ii) compared with major city centres, inner regional centres had a relative risk of 1.32 (1.18, 1.48), but the risk was not elevated for more remote sites at 0.95 (0.74, 1.22). Risk of death was not related to private insurance status. CONCLUSION: Higher breast cancer mortality in patients treated in inner regional than major city centres and in those treated by surgeons with lower case loads requires further study.