36PGENE EXPRESSION ANALYSIS OF TRIPLE NEGATIVE RECURRENT LYMPHANGITIC BREAST CANCER IN PATIENTS RECEIVING ANTIANGIOGENIC THERAPY

Purpose: To identify a gene signature predictive of response to treatment with bevacizumab. To assess efficacy and safety of bevacizumab in combination with oral chemotherapy in patients with inflammatory breast cancer. Patients and methods: We randomly assigned patients to receive oral vinorelbine 55 mg/m2 on days 1 and 3 and capecitabine 2000 mg/m2 from day 1 to 14 every 3 weeks either concurrent or sequential to bevacizumab 15 mg per kilogram of body weight on days 1 and 21. The primary end point was progression-free survival; the response rate and overall survival were secondary end points. We performed gene expression profiling on collected baseline tissue samples using Affymetrix HG-U133 Plus 2.0 arrays. Results: From July 2007 through October 2011, a total of 66 patients were enrolled. Concurrent oral vinorelbine and capecitabine plus bevacizumab significantly increased the objective response rate as compared to the sequential treatment (11.1% vs. 46.4%, P < 0.001). No difference in progression-free survival was observed between the two arms (median time to progression 4.3 vs. 4.7 months, p = 0.69; Hazard Ratio: 0.86, 95% CI: 0.41–1.80). Global gene expression was analyzed in tumor samples from patients bearing a triple negative phenotype. A set of 75 genes was identified, this gene signature correlates with response to bevacizumab. Conclusions: Oral vinorelbine plus capecitabine and bevacizumab (BEVIX) is an active treatment for patients with recurrent lymphangitic breast cancer. We identified a set of 75 genes whose expression levels predict the response to BEVIX. Disclosure: All authors have declared no conflicts of interest.