TARGIT-A trial: Updated results for local recurrence and survival for the German centers.

Abstract

1121 Background: In 2010, we reported data on local control and early toxicity for the TARGIT-A trial of intraoperative radiotherapy after lumpectomy for early breast cancer. The updated results and first analysis of survival of the whole cohort (n = 3,451) were presented at San Antonio Breast Cancer Symposium in December 2012. We analysed the German cohort of patients, which was supposed to be more homogeneous (prepathology IORT only, homogeneous treatment in EBRT arm) and lower risk (older, smaller tumors, larger margin) than the international cohort of patients due to legal restrictions for radiotherapy studies in Germany. Methods: TARGIT-A was a randomised trial in patients >=50 years with invasive ductal carcinoma (<= 2cm) undergoing breast conserving surgery comparing standard fractionated whole breast EBRT (56 Gy) with single dose TARGIT (20 Gy) immediately after tumor excision / at the time of the primary operation. The experimental arm mandated additional EBRT (46 Gy, excluding a boost, n = 126) if adverse features were detected on final pathology (EIC, N+, margin < 1 cm) making this a “risk-adapted policy”. Median follow-up was 2 years and 5 months. Results: 734 patients recruited from 7 centres in Germany. Patient’s ages were <=50y 3%, 51-60y 33%, 61-70y 51%, >70y 12%. Tumour sizes were 0-1cm 35%, 1.1-2cm 55% and >2cm 11%. Grade I 29%, II 59%, III 12% and nodes negative 81%, 1-3 nodes 16%, >3 nodes 3%. At 5-years, the absolute number of events in TARGIT vs. EBRT were as follows: Primary outcome: IBR 4 vs. 1, Exploratory outcome: All recurrences (breast +axilla+contralateral+distant recurrence) 11 vs. 7, Secondary outcome: All deaths 6 vs. 12, Breast Cancer deaths 3 vs. 5, Non-Breast Cancer deaths 3 vs. 7. Conclusions: Patients in the TARGIT-A trial have excellent 5 year outcomes (local control > 97%, overall survival >= 94%) in both arms of the trial. Clinical trial information: protocol 99PRT/47.