Abstract P4-10-19: Disparities in use of adjuvant radiotherapy following lumpectomy among California regions

Abstract

Abstract Background Women undergoing lumpectomy for invasive breast cancer typically receive radiotherapy (RT) to reduce risk of recurrence. Previous studies have reported disparities in the utilization of RT by race, socioeconomic status (SES), and age. In this study, we evaluate whether various sociodemographic factors are associated with use of RT in the different regions of California. Methods Utilizing data from the California Cancer Registry, the authors identified cases of women whose first primary invasive breast cancer was diagnosed between January 1, 2007 and December 31, 2012, whose primary surgery was breast conserving surgery, and for whom information was complete (n = 71,767). Multivariate logistic regression was used to determine whether demographic factors (SES, race, payer status, age) were significantly associated with use of RT following lumpectomy (p < .05), adjusting for tumor characteristics (size, stage, grade, hormone receptor status, and nodal status). Results In three out of eight regions in California, black race was associated with decreased odds of RT use (San Francisco, OR = 0.79, 95% CI = 0.68-0.92; Desert Sierra, OR = 0.72, 95% CI = 0.58-0.90; Los Angeles, OR = 0.78, 95% CI = 0.70-0.87). In Sacramento and Los Angeles regions, lower socioeconomic status was associated with declined odds of RT use. Age (70 years or older) was also associated with lower likelihood of RT use across all regions. Conclusions Even after accounting for payer status, racial and socioeconomic disparities persist in the use of RT. These disparities, previously documented in the time period of 2000-2007, have not disappeared. Hispanic race was not shown to be associated with decreased odds of RT use in Los Angeles, contrary to the results of a previous study. Women aged 70 years or older are less likely to receive RT. Citation Format: Huang RJ, Mukhtar RA, Alvarado M. Disparities in use of adjuvant radiotherapy following lumpectomy among California regions [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P4-10-19.