The importance of location in determining breast conservation rates

Abstract

This study evaluates differences in the utilization of breast conservation surgery (BCS) between major metropolitan areas in the United States (US) and the United Kingdom (UK). Surgical and staging information were obtained from the Cancer Surveillance Program for Los Angeles County (LAC), the New York State (NYS) Department of Health Cancer Registry, and the UK National Health Service (NHS) Breast Screening Program. Demographic data were obtained from the census databases from the US, UK, Northern Ireland, and Scotland. Descriptive statistics, correlation analysis, and chi-square tests were used to compare rates of BCS across the locations under study. Breast conservation rates were highest in London (79.3%) compared to New York City (NYC) (69.7%) and LAC (66.5%) (P < .0001). Both in NYS and the UK, the cities differ from the surrounding regions in population density, education levels, agricultural activities, and unemployment. BCS rates tended to increase with population density and education levels, and decrease with increased unemployment and agricultural activity, but there was no impact on BCS rates when adjustments for these variables were included in regression models. BCS rates increase with increasing hospital case volume in LAC and NYC (P < .0001). When comparing large metropolitan areas in the US and UK there are significantly different rates of BCS in different locations. These differences reflect differences in population density, socioeconomic status (SES), education levels, hospital volume, and the effects of a nationally funded screening program.