Is Postoperative Supraclavicular Fossa Radiation Therapy Necessary After Neoadjuvant Chemotherapy in Yp N Stage 0-1 Breast Cancer?

Abstract

up to one year after surgery. 28 patients were triple negative (TARGIT: 16; EBRT: 12) and 42 patients were HER2 positive (TARGIT: 24; EBRT: 18). Disease free survival and overall survival were compared. Results: Median follow-up was 49 months. The 5-year Kaplan-Meier estimate of overall survival showed no significant difference in HER2 positive tumors: TARGIT 0 events 100%, EBRT 1 event 91.7%, log-rank P Z 0.22. The same was seen for disease free survival: TARGIT 2 events 83.3%, EBRT 4 events 77.0%, log rank P Z 0.38. The results for triple negative cases were similar. Overall survival: TARGIT 2 events 87.5%, EBRT 3 events 74.1%, log rank P Z 0.488. Disease free survival: TAR-GIT 2 events 87.5%, EBRT 4 events 60%, log rank P Z 0.22. Conclusion: Although trends were favorable for TARGIT-IORT, no significant differences could be shown and the significantly positive result for overall survival in the whole cohort of 116 patients could not be reproduced in this substudy on triple negative and HER2 positive tumors. The reason for this may be the small number of events, but it may also indicate that the results for the whole cohort were mainly driven by ER and/or PR positive and HER2 negative patients.