Outcomes After Multidisciplinary Treatment of Inflammatory Breast Cancer in the Era of Neoadjuvant HER2-directed Therapy

Objectives: We previously reported survival trends among patients with inflammatory breast cancer (IBC) over a 30-year period before 2005. Here we evaluated survival outcomes for women with IBC diagnosed before or after October 2006, in the era of HER2-directed therapy and after opening a dedicated multidisciplinary IBC clinic. Methods: We retrospectively identified and reviewed 260 patients with newly diagnosed IBC without distant metastasis, 168 treated before October 2006 and 92 treated afterward. Most patients received anthracycline and taxane-based neoadjuvant chemotherapy, mastectomy, and postmastectomy radiation. Survival outcomes were compared between the 2 groups. Results: Median follow-up time was 29 months for the entire cohort (39 and 24mo for patients treated before and after October 2006). Patients treated more recently were more likely to have received neoadjuvant HER2-directed therapy for HER2-positive tumors (100% vs. 54%, P=0.001). No differences were found in receipt of hormone therapy. Three-year overall survival rates were 63% for those treated before and 82% for those treated after October 2006 (log-rank P=0.02). Univariate Cox analysis demonstrated better overall survival among patients treated after October 2006 than among those treated beforehand (hazard ratio [HR] 0.5; 95% confidence interval [CI], 0.34-0.94); a trend toward improved survival was noted in the multivariate analysis (HR = 0.47; 95% CI, 0.19-1.16; P= 0.10). Significant factors in the multivariate model included HER2-directed therapy (HR = 0.38; 95% CI, 0.17-0.84; P=0.02) and estrogen receptor positivity (HR = 0.32; 95% CI, 0.14-0.74; P=0.01). Conclusions: Survival improved in the context of the IBC clinic and prompt initiation of neoadjuvant HER2-directed therapeutics.