Department of Radiation Oncology, the Section of Health Services Research, the University of Texas MD Anderson Cancer Center, 1515 Holcombe Blvd., Houston, TX 77030, USA.
BACKGROUND: Breast-conserving surgery (BCS) followed by radiotherapy is as effective as mastectomy for treatment of early invasive breast cancer. But earlier studies report low BCS use rates of 12% to 43% nationally, especially in older patients. We sought to determine current patterns and predictors of BCS use. STUDY DESIGN: In a national Medicare database of all beneficiaries (age greater than 65 years) with incident invasive breast cancer treated with operation in 2003, claims codes identified BCS versus mastectomy and demographic, treatment, and geographic region covariates. The 2003 Area Resource File provided socioeconomic covariates. Logistic regression modeled predictors of BCS. RESULTS: In 56,725 women, 59% were treated with BCS versus 41% with mastectomy. BCS was more likely in women who were younger than 70 years (odds ratio [OR], 1.37; 95% CI, 1.31 to 1.44; p < 0.001) and had lymph node-negative disease (OR, 1.60; 95% CI, 1.52 to 1.68; p < 0.001). Socioeconomic factors influenced use, with BCS more likely in areas with low poverty (OR, 1.05; 95% CI, 1.00 to 1.09; p = 0.03), high education (OR, 1.13; 95% CI, 1.08 to 1.19), high density of radiation oncologists (OR, 1.30; 95% CI, 1.06 to 1.59), and in metropolitan areas (OR, 1.20; 95% CI, 1.14 to 1.26). Significant geographic variation existed: 70% of women were treated with BCS in northeastern New England compared with only 48% to 50% in the South (p < 0.001). CONCLUSIONS: Currently, more than half of older women across the US diagnosed with nonmetastatic invasive breast cancer treated surgically receive BCS, representing a substantial increased use compared with historical data. Lack of BCS use appears in part associated with socioeconomic disadvantage, suggesting that persistent barriers to breast conservation exist.