Abstract 3842: Relationship between weight change and response to trastuzumab-based neoadjuvant chemotherapy among women with operable HER2 overexpressing breast cancer

Abstract

Abstract Purpose Weight change (gain or loss) in early breast cancer patients is associated with worse survival. However, limited research investigates the impact of weight change in the neoadjuvant setting in women with HER2 overexpressing breast cancer. The goals of this study were to examine i) the relationship between weight change during trastuzumab-based neoadjuvant chemotherapy and pathologic response, and ii) determine whether weight change during post-operative trastuzumab was associated with outcome. Patients and methods From March 2004 to March 2013, 52 patients diagnosed with invasive non-metastatic HER2 overexpressing breast cancer were recruited from H.S. Kaplan Cancer center, France. They received trastuzumab-based neoadjuvant chemotherapy (NAC) before surgery, followed by adjuvant trastuzumab. Patients were distributed in the “weight loss” or “weight gain/stable” categories according to their relative weight change after NAC, and after adjuvant trastuzumab. Logistic regression was used to examine associations between weight change and pathologic response. The Kaplan-Meier method and Cox proportional hazards regression analysis were used to evaluate the relationship between weight change and progression free survival (PFS). Results Median age was 50 years (range 21 to 71 years); 25% of women experienced body weight loss during NAC, 40% had stable body weight, and 35% gained weight. In multivariate analysis, weight loss was significantly associated with worse pathologic complete response (pCR) in tumor compared with the weight gain/stable group (OR = 0.18; 95% CI, 0.04 to 0.84). There was no difference in pCR in nodes according to weight change (OR = 0.34; 95% CI, 0.06 to 1.76). Body mass index was not associated with pCR. At a median follow up time of 3 years, PFS was not associated with weight change during NAC but with weight change during adjuvant trastuzumab. PFS was worse in patients loosing weight during adjuvant trastuzumab (OR = 0.05; 95% CI, 0.01 to 0.34). Conclusion Weight loss was associated with worse pCR to trastuzumab-based neoadjuvant chemotherapy. In addition, weight loss during adjuvant trastuzumab was associated with worse PFS. These results suggest that weight control and promotion of weight maintenance in women with HER2 overexpressing breast cancer should be integrated within cancer treatment to optimize patient outcomes. Citation Format: Nawale Hajjaji, Dorothee Chocteau, Sylvie Gerard, Marie Brigitte Orgerie. Relationship between weight change and response to trastuzumab-based neoadjuvant chemotherapy among women with operable HER2 overexpressing breast cancer. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 3842. doi:10.1158/1538-7445.AM2014-3842