Very long term follow-up of high dose chemotherapy followed by autologous stem cell transplantation in high risk locally advanced triple negative breast cancer.

Abstract

e13094 Background: The role of High Dose Chemotherapy (HDC) with Autologous Stem Cell Transplantation (ASCT) in treatment of high risk locally advanced breast cancer remains unclear. This modality stopped being used for breast cancer treatment when trials in early 2000s reported Disease Free Survival (DFS) benefit but no Overall survival (OS) benefit. However, subgroup analyses of these studies reported OS benefit in young and Triple Negative Breast Cancer (TNBC). We report very long-term outcomes of high risk locally advanced TNBC treated with HDC-ASCT at our institution between 1995 and 2001. Methods: We reviewed our BMT database for women with stage IIB or III TNBC treated with HDC-ASCT. We excluded women with hormone positive, Her2/Neu positive/Unknown and metastatic disease prior to transplant per updated AJCC 7th edition. The majority of patients underwent surgery followed by adjuvant Anthracycline and Taxane based induction chemotherapy followed by HDC-ASCT for consolidation. The HDC regimen consisted of Carmustine 600 mg/m2, Cyclophosphamide 5.6gm/ m2 and Cisplatin 165mg/ m2 (STAMP 1 regimen). Four patients received induction regimen as neoadjuvant and HDC-ASCT as adjuvant treatment per the same protocol. All patients received loco-regional radiation after ASCT. Results: 29 patients had locally advanced TNBC treated with HDC-ASCT. Median age at diagnosis was 43 years (IQR 40-51). 28 had at least 4 positive lymph nodes. Median time from diagnosis to ASCT was 5 months. Median overall survival was 17 years (95% CI, 3-19 years), and median DFS was 14 years (95% CI, 1-19). There was no treatment related mortality (TRM) at 30- and 100-days post ASCT. 12 patients (41%) were alive at median of 16 years (95% CI, 12-19) post ASCT. Conclusions: This single institution study of locally advanced high risk TNBC patients who received HDC-ASCT as part of treatment demonstrates a high long term OS exceeded historical controls. This supports a potential role for HDC-ASCT in this cohort of high risk TNBC. Considering the low TRM associated with this approach, prospective evaluation of this strategy is warranted.