Abstract P1-14-03: Overall survival results of a multicenter randomized phase II study in locally advanced breast cancer patients treated with or without neoadjuvant Trastuzumab for HER2 positive tumor (Remagus 02 trial)

Background: Trastuzumab is indicated in neoadjuvant setting in locally advanced HER2 positive breast cancer patients (Gianni L. Lancet 2010). There is no data on the impact of the use of neoadjuvant Trastuzumab (T) compared to adjuvant T on survival. Patients and methods: From May 2004 to October 2007, 341 stage II-III breast cancer patients were included in a phase II randomized trial and received 4 cycles (c) of epirubicin (75 mg/m2 d1)–cyclophosphamide (750 mg/m2 d1) q 3 w followed by 4 (c) of docetaxel (100 mg/m2 d1) q 3 w. Pts with HER2+++ tumor (120 pts) were randomized to receive or not neoadjuvant T combined with docetaxel. From September 2005, all pts with HER2+cancer received adjuvant T for a total of 18 c (106 pts). All pts with hormone receptors positive tumor received hormonal treatment according to menopausal status (Pierga et al BCRT 2010). We report here overall survival (OS) and disease free survival (DFS) data at 5 year and associated prognostic factors. Results: At a median follow up of 49 months, the median DFS was not reached for the whole population and was statistically superior for the HER2 positive cancer patients treated with chemotherapy plus neoadjuvant T compared to the other groups, p = 0.018. The median OS is not reached for the whole population and is statistically higher in HER2 positive tumor group compared to HER2 negative group (p = 0.00077). For 106 HER2 positive breast cancer patients who had received one year of complete trastuzumab treatment, there was no significant difference in OS and DFS between pts who started T in neoadjuvant setting versus in adjuvant setting. DFS and OS were not significantly influenced by pathological Complete Response rate (pCR) (respectively, p = 0.22 and p = 0.56). At multivariate analysis including 6 factors (age, tumor size, clinical lymph node, ER, PgR), factors which influenced OS were tumor size (p = 0.03) and ER expression (p = 0.06) and for DFS, clinical lymph node status (p = 0.049) and PgR expression (p = 0.046). Conclusion: pCR is not a surrogate of survival in the HER2+subgroup. HER2 positive breast cancer pts receiving trastuzumab have a significant higher OS than those with HER2 negative tumors. OS and DFS do not seem to differ between the neoadjuvant T group and the T adjuvant group. Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P1-14-03.