Abstract P5-14-14: Trimodality therapy for inflammatory breast cancer: The fox chase experience

Abstract

Abstract Objective: To evaluate the outcomes and toxicity of inflammatory breast cancer (IBC) patients (pts) treated with trimodality therapy. Materials and Methods: A retrospective chart review of 71 non-metastatic women with IBC treated using once daily (QD) radiation fractionation between 1990 and 2011 was performed. Eighty-six% of pts underwent ER/PR receptor status testing, and 43% underwent HER-2 testing. All pts underwent a course of neoadjuvant chemotherapy. Forty-three pts had adjuvant hormonal therapy, and 7 had adjuvant trastuzumab. All pts underwent mastectomy with axillary lymph node dissection followed by chest wall irradiation to a median dose of 50 Gy (34-50), and 46 Gy to supraclavicular region in 2-Gy QD fractions. Internal mammary nodes were treated in 3 pts (4%) and a posterior axillary boost (PAB) was added in 32 (45%) cases. Scar boosts (SB) were employed in 6 patients. A univariate (UVA) analysis using Kaplan-Meier estimation method included cN, pN, pT stage, PAB, SB, dermal lymphatic invasion, lymphovascular invasion, body mass index, response to chemo (RC), close/positive surgical margins (SM), age, and triple negative (TN) receptor status. Significant predictors on UVA were included in multivariate (MVA) analysis using the Cox proportional hazard model. Primary endpoints included local-regional recurrence (LRR), distant metastasis (DM), overall survival (OS), cause specific (CSS) and disease-free survival (DFS). Acute and chronic skin reactions and lymphedema were evaluated. Results: Median follow-up was 34 months (2-265) and the median age was 56 years (36-82). Actuarial 3 and 5 year OS was 63% and 43%, and DFS was 51% and 43%, respectively. The median time to first failure, LRR, and DM was 20 mo (1.5-147), 13.5 mo (9-18), and 21 mo (1.5-147), respectively. The first site of failure was distant for 34 (48%), and local-regional for 4 pts (6%). Twenty-five pts (35%) were without failure at the time of last follow up. UVA analysis for LRR revealed SM (p = 0.05) and RC (p = 0.002) to be significant predictors of failure, however, these were not significant on MVA. UVA for DM identified SM (p = 0.03), TN (p<0.0001), and pN (p = 0.03) to be significant predictors, with TN (p = 0.002) being the only significant variable on MVA. Significant predictors for OS on UVA were TN (p = 0.04), pN1 vs pN2 disease (p = 0.02), SM (p = 0.0008) and RC (p = 0.008). None of these remained significant on MVA. Significant predictors for CSS on UVA were TN (p = 0.008), pN (p = 0.05), SM (p = 0.0004) and RC (p = 0.002). Only SM (p = 0.01) was predictive on MVA. Significant predictors for DFS on UVA were SM (p = 0.0003), pN1 vs pN2 (p = 0.05), RC (p = 0.0006) and TN (p = 0.0001). Only RC (p = 0.005) and TN (p = 0.001) remained significant on MVA. Twelve pts developed dry, and 14 developed moist desquamation. Three pts developed CTCAE v3 G3 lymphedema, and 5 pts experienced G3 fibrosis. Conclusions: We found that TN predicted for a higher rate of DM and worse DFS. Improved CR predicted for better DFS. Age < 45, SM, pN2 disease and poor RC were not predictive of LRR. Use of SB did not improve LRR, although this cohort was small. Overall, our results show encouraging 3 and 5 year OS rates and acceptable toxicity for IBC pts treated with trimodality therapy. Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P5-14-14.