Weight Gain during Neoadjuvant Chemotherapy is Associated with Worse Outcome among the Patients with Operable Breast Cancer

PURPOSE: This study was aimed at identifying the influence of initial weight and weight change during neoadjuvant chemotherapy (NAC) on pathologic complete response (pCR) and long-term survival in Chinese patients with operable breast cancer. METHODS: We conducted a retrospective study using data from 409 female patients who received NAC for stage II or III breast cancer and had complete record of body mass index (BMI) before and after NAC. BMI of < 25 kg/m(2) was categorized as normal weight/underweight (NW/UW); 25.0–29.9 kg/m(2) was categorized as overweight (OW); ≥30 kg/m(2) was categorized as obese (OB). BMI change was defined as the difference in BMI between day 1 of the first cycle of NAC and the day before surgery. A BMI gain or loss of > 2 kg/m(2) following NAC was considered to be significant, else was considered stable. The study end points included pCR rates, disease-free survival (DFS), and overall survival (OS). RESULTS: The median follow-up time was 43.2 (8.9–93.6) months. The average BMI was 23.40 ± 3.04 kg/m(2) before NAC and 23.66 ± 3.02 kg/m(2) after NAC (t = −3.604, p < 0.001). The pCR rate was 25.3% in the NW/UW group and 24.1% in the OW/OB group (p = 0.811), and was similar between the BMI-gain (23.3%) and the BMI-stable/loss (25.1%) groups (p = 0.787). Initial BMI was an independent prognostic factor for DFS (hazard ratio, 1.69; 95% confidence interval [CI], 1.13–2.53; p = 0.011) but not for OS, while BMI-gain was an independent prognostic factor for both DFS (hazard ratio, 2.09; 95% CI, 1.28–3.42; p = 0.003) and OS (hazard ratio, 1.97; 95% CI, 1.04–3.74; p = 0.039). CONCLUSION: BMI increased after NAC in Chinese breast cancer patients. Initial BMI and BMI change during NAC were not associated with pCR but were reversely associated with survival.