Adjuvant high-dose chemotherapy with autologous hematopoietic stem cell transplantation for breast cancer with > 3 positive nodes: 15 years results from the GITMO registry.

Background: The role of adjuvant high-dose chemotherapy (HDC) with autologous hematopoietic stem-cell transplantation for primary breast cancer (BC) at high risk of recurrence (> 3 LN+) has not been well defined yet. Recently reported trials have demonstrated that this approach could have a role in selected pts. Aim of this study is to retrospectively evaluate toxicity and efficacy of HDC with HSCT in a large cohort of pts receiving HDC in Italy between 1990 and 2005. Methods: 1294 BC pts receiving HDC for poor risk BC were identified in the Italian registry (GITMO). In 1183 pts with >3 LN, a thorough data set including biological characteristics, toxicity and follow up was available. Median age was 46 years (24-66), 62% of pts were pre menopausal at treatment, 71% had an endocrine responsive tumours and 43% had a HER2+ tumour. The median number of LN+ was 15 (4-63). 76% of pts received alkylating agents-based HDC as a single procedure while 24% received Epirubicin or Mitoxantrone-containing HDC, usually within a multitransplant program. Source of stem cells was peripheral blood in 99% of pts. Results: Transplant related mortality (TRM) at 100 days was 0.7%, while late cardiac and secondary tumour-related mortality were around 1% overall. With a median follow up of 79 months, median disease free survival (DFS) and overall survival (OS) in the entire population were 115 months and not reached, respectively. Subgroup analysis demonstrated that OS was significantly better in endocrine responsive tumours (p=0.0009), while menopausal or HER-2 status did not affect survival. Median OS was significantly better (p=0.0000) in pts receiving multiple transplant procedures. Conclusions: In our series of poor risk pts HDC with HSCT has low TRM and high efficacy. Multiple transplants seem more active than single HDC procedures. This analysis could be useful in selecting well defined patient populations in which to re-address the role of HDC as adjuvant treatment. The study was conducted on behalf of Gruppo Italiano per il trapianto di Midollo, di Cellule Staminali emopoietiche e di terapia cellulare (GITMO).