Utilization of post-lumpectomy radiation therapy in women 70 years of age or older: A report from the National Cancer Data Base

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