1033 Background: The Cancer and Leukemia Group B (CALGB) 9343 trial published in 2004 showed no overall survival benefit from radiation in patients >70 years old with estrogen receptor (ER) positive, pT1 tumors with the use of tamoxifen. We tested the hypothesis that the use of radiotherapy decreased in this group of patients following publication of the trial, utilizing the National Cancer Data Base. Methods: 34,853 breast cancer patients 70 years or older with pT1N0/NX, ER positive tumors who underwent a lumpectomy between 2004 and 2007 were studied. Chi-square tests and logistic regression models were used to determine trends and factors related to the use of radiation. Results: The use of radiation decreased from 70.6% in 2004 to 66.4% in 2005, 66.6% in 2006, and 67.2% in 2007 (p<0.001). The use of standard external beam radiation decreased from 58.8% in 2004 to 45.8% in 2007 while the use of accelerated partial breast radiation using brachytherapy (APBI) increased from 4.5% to 10.0%, IMRT radiation from 3.1% to 5.3%, and 3D conformal radiation from 3.7% to 5.7% (p<0.001). Patients between the ages of 86+ years old were less likely to undergo radiation than patients 70-75 years old (OR=0.12, 95% CI: 0.11-0.13). Asian Pacific Islanders were more likely to undergo radiation than whites (OR=1.39, 95% CI: 1.13-1.70). In community cancer programs, 67% patients received radiation, compared to 69.1% in comprehensive community programs and 65.5% in academic programs (p<0.001). The use of radiation varied by facility location; 73.5% of facilities located in the Midwest radiated these patients as opposed to 62.6% in the South. In patients who had no nodes examined, 37% underwent radiation as opposed to 74% who did have nodes examined (p<0.001). Likewise, 79.4% of patients who received hormone therapy underwent radiation as opposed to 54.6% of patients who did not receive hormonal therapy (p<0.001). Conclusions: The use of radiation therapy decreased only slightly and remained high in women with ER+ stage I breast cancer over the age of 70, despite findings from the CALGB 9343 study. However, there was a large shift in radiation modality over the study period in the older patients.
Practice Patterns and Outcomes for Postmastectomy Radiation After Complete Pathological Response in Stage II and IIIA Breast Cancer Patients: Analysis of the National Cancer Data Base
