Disparities in receipt of adjuvant radiation therapy after breast‐conserving surgery among the cancer‐reporting regions of California

Abstract

Incidence and mortality of breast cancer vary according to demographic factors such as age, race/ethnicity, socioeconomic status (SES), and geographic region. This study assesses the variation of these factors in the use of adjuvant radiation therapy (RT) after breast-conserving surgery (BCS) among 8 regions of California. The authors identified 85,574 cases of first primary female invasive breast cancer with complete data diagnosed between January 1, 2000 and December 31, 2007. Logistic regression was used to determine the association between race/ethnicity, age, SES, and receipt of RT after BCS within each of the regions of California. Odds ratios (ORs) and 95% confidence intervals (CIs) were computed. Age was a significant predictor of receipt of RT after BCS in all regions. In Los Angeles (LA), lower SES was associated with decreasing odds of RT. Racial disparities were evident only in LA, where black (OR, 0.85; 95% CI, 0.74-0.97) and Hispanic (OR, 0.86; 95% CI, 0.78-0.96) women were about 15% less likely to receive RT than white women. Racial disparities in the receipt of RT after BCS exist only in LA, where African American and Hispanic women are less likely to receive this form of adjuvant treatment. Lower SES was also associated with a reduced likelihood of receipt of RT in LA. Women age 70 years and older are less likely to receive RT after BCS in all regions of California.