Weight Variation during Chemotherapy and Breast Cancer Prognostic.

Abstract

Abstract Introduction: Relationships between overweight and cancer have been described for a long time. First, obesity increases the risk of cancer at several sites, including breast cancer. Furthermore, overweight has been linked to adverse outcome in women with breast cancer, which mecanisms are not completely understood. After breast cancer development, numerous studies report a weight gain due in part to the effects of some treatment regimens, most notably chemotherapy. As observed in few studies, especially in US population, weight gain after breast cancer diagnosis may have an adverse effect on survival and recurrence of breast cancer. The aim of our study was to evaluate whether weight variations during chemotherapy are predictive of breast cancer survival and recurrence in an european population.Materials and methods : between 1976 and 1989, 141 women treated at Centre Jean Perrin (Clermont-Ferrand, France) for non-metastatic breast cancer by adjuvant or neo-adjuvant chemotherapy have been included in our series to have at least 20 years of follow-up for the study. The median follow-up was 20.4 years [19.4-32.5]. Weight was measured prospectively at baseline and at each cycle of chemotherapy. Patient were included if they had received neoadjuvant or adjuvant anthracycline-based chemotherapy, and if weight assessement included at least 3 measurements with necessary one at baseline and another at the end of chemotherapy. Body mass index (BMI) and weight variation (WV) on overall survival (OS) and disease free survival (DFS) (local recurrence and distant metastasis) were explored. Threshold of WV was fixed at 5% (gain or loss) of the initial body weight.Results : Median age of patients was 54 years [32- 75] and 57% were menopaused. Patients received a median of 6 cycles [2-15] of anthracycline-based chemotherapy. Initial median BMI was of 24.4 kg/m2 [16.6 -40.5]. During chemotherapy treatment, weight was stable (median of relative WW of 0% [-10.9-15.4]), 17% of patients lost weight (WV < -5%), 68% were stable (-5 5%).In the univariate analysis, patients with a baseline BMI lesser than 24 kg/m2 had a better OS than those with initial BMI higher than 24 kg/m2 (p = 0.026). Indeed, there was a significant difference in DFS between these two groups (p = 0.027).Moreover, there was a significant difference in OS between patients whose weight varied beyond 5% compared to patients who maintained their weight (p = 0.048). This effect was also observed on DFS (p = 0.033).In a multivariate analysis, that included tumor size and node involvement, we found that WV more than 5% was associated with a significantly OS decrease (risk ratio, 1.83; 95% CI, 1.08 to 3.08; p = 0.024) and a higher risk of recurrence (DFS: risk ratio, 1.95; 95% CI, 1.14 to 3.32; p = 0.014).Conclusion : our study showed that weight variations were associated with a higher risk of death and recurrence (local and distant metastasis) in breast cancer patients. Consistent with these results, weight management should be directed to maintain weight during chemotherapy treatment of non-metastatic breast cancer in future interventional studies. Moreover, further studies are needed to explore biological mecanisms of such a clinical observation. Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 6049.