Abstract P4-11-04: The Influence of Radiation on Survival in Patients with Triple Negative Stage II Breast Cancer

Abstract

Abstract Background: Prospective trials of locally advanced breast cancer patients treated with adjuvant radiation (RT) have demonstrated a survival advantage; however, use of postmastectomy RT in stage II patients is controversial. This study explores the possibility that patients with aggressive variant molecular subtypes [triple receptor negative (TN)] treated with modern chemotherapy, may experience a survival benefit from adjuvant RT. Methods: Billing codes for all breast cancer patients treated with chemotherapy between 1/1998 and 5/2005 at the University of Alabama at Birmingham were reviewed to comprehensively capture all Stage II and III patients with intact data. Patient, tumor, and treatment related variables were recorded and patients were divided into 3 molecular subtypes based on receptor status: hormone receptor (HR) positive, Her2 negative; HR+/− , Her2+; and TN. Kaplan Meier curves to assess survival were performed by dividing the TN group into 2 groups: those who did or did not receive adjuvant RT. Results: 409 patients with stage II-III disease with were identified. Out of this group, 81 patients had TN breast cancer (60 Stage II and 21 Stage III). RT data was known in 79 of these patients. Median age was 49 years. Median follow-up was 72 months. Thirty-seven stage II and 18 stage III patients received adjuvant RT. Of the stage II patients who received radiation, 25 underwent lumpectomy and 11 underwent mastectomy. Stage II patients who received adjuvant RT had a statistically significant improvement in DFS (p=0.03), and had a trend towards improvement in OS (p=0.07) when compared with those who did not receive adjuvant RT. There was no significant difference in survival for the stage III patients with use of RT, however numbers in this group were small. Conclusion: Adjuvant RT was associated with an improvement in DFS and a trend towards improvement in OS in patients with Stage II, TN breast cancers treated with modern chemotherapy. Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr P4-11-04.