Long term follow up of patients with locally advanced triple negative breast cancer treated with adjuvant high dose chemotherapy and autologous stem cell transplantation: A single center experience.

Abstract

e12590 Background: Adjuvant high dose chemotherapy (HDC) with Autologous Hematopoietic Stem Cell Transplantation (AuSCT) as part treatment of high risk locally advanced breast cancer has remained controversial. Multiple trials reported disease free survival (DFS) without Overall survival (OS) resulting in its abandonment in early 2000s. However, post hoc analysis of these trials consistently reported DFS and OS benefit in young and triple negative breast cancer (TNBC) subgroups. This has not been re-evaluated till date. Recent European registry reports coupled with improved transplant related mortality (TRM) and still poor out-come of standard of care in TNBC subgroup has generated renewed interest. We report long term out-come of locally advanced high risk TNBC treated with HDC and AuSCT treated in Karmanos Cancer Institute from 1995 to 2001 Methods: Majority of the patients were treated with Adriamycin and Taxane based induction chemotherapy. Patients without evidence of metastatic disease proceeded to HDC and AuSCT using Carmustine 600mg/sqm Cyclophosphamide 5.6gm/sqm and Cisplatin 165mg/sqm (STAMP 1 regimen). This is followed with loco- regional radiation per protocol. Results: 72 hormone negative patients with Lymph Node(LN) > 4 or inflammatory breast cancers were selected from 576 treated for advanced or metastatic breast cancer. 33 patients were TNB with HER2 status of 39 patients unknown. Median time from diagnosis to stem cell transplantation was 6 months. Median age at diagnosis was 47yrs. Mean LN involvement was 9 with 90% having (4-20) LN positivity. With median follow up of 16 years,10yrs DFS and OS were both 62.5%. Median follow up for DFS and OS was not reached.TRM was 9% mostly from pulmonary toxicity. Conclusions: This study of locally advanced high risk TNBC treated with adjuvant HDC and AuSCT have high 10yr OS of 62.5% compared to current standard of care. With the current improvement in TRM, reevaluation of this strategy through clinical trials in this subgroup whose outcome remain poor is reasonable.