362P CYBERNEO trial: Update of results at 14 years of follow-up

The purpose of the phase I “CYBERNEO” trial was to define the efficacy of the CyberKnife®(CK) for locally advanced (stage III) breast tumors combined to a neo-adjuvant treatment with chemotherapy for patients for whom a conservative surgery could not be considered at the onset. Neoadjuvant chemotherapy (NAC) consisted of 6 cycles: 3 cycles of docetaxel and 3 cycles of 5-fluorouracil-epirubicin-cyclophosphamide (FEC). CK was performed during the second cycle of chemotherapy. Breast surgery was performed six to eight weeks later and conventional breast irradiation without boost, afterwards. The main objective was to define the maximum tolerated dose of hypofractionated radiotherapy concurrent with NAC.We present an updated survival data for patients included in this trial and we evaluate the late toxicities of this combination. We updated the survival data of 25 patients treated for a stage III breast cancer between 2007 and 2009 at the Antoine Lacassagne Center in Nice and included in the CYBERNEO trial by recording late toxicities and esthetic results. With a median follow-up of 12 years, 95% CI [10-14], 19 patients (76%) were in remission, 1 patient had a controlled axillary lymph node relapse (4%) band 5 patients (20%) died due to metastatic progression within a median of 5 years after treatment (min: 1, max: 9). Nine patients (36%) had a complete histological response (pCR). The highest percentage of pCR was in the group of patients treated in the 4th stage (28.5 Gy in 4 fractions). Overall survival at 14 years was 71%, 95% CI [53%-94%]. Two patients developed chronic radiation toxicity during follow-up with a fibrosis (8%), of which one was in the 4th stage and one in the 5th stage (31.5 Gy). Three patients (12%) had a change of prosthesis after treatment which for one patient was 24 months after the end of support. The updated results of the CYBERNEO trial with 14 years of follow-up confirm the satisfactory results in terms of local control with an excellent long-term safety profile.