Abstract P1-08-22: The impact of obesity on response to neoadjuvant chemotherapy in operable breast cancer patients

Abstract

Abstract Background The association between obesity and response to neoadjuvant chemotherapy in breast cancer patients is not clear. We evaluated the impact of obesity on response to neoadjuvant chemotherapy in patients with operable breast cancer. Methods From May 2008 to December 2010, 104 patients were diagnosed with invasive breast cancer at Korea University Anam Hospital and received neoadjuvant chemotherapy before surgery. Patients were classified into those of normal (BMI of 18.5 to <25kg/m2), overweight (BMI of 25 to <30kg/m2), or Obese (BMI≥30kg/m2). The association between body mass index and pathologic response (pathologic complete response(pCR) and pathologic partial response(pPR)) to neoadjuvant chemotherapy was examined using logistic regression. Results Median age was 45 years. Mean BMI was 24.8 kg/m2; 53.8% had a normal BMI, 35.6% overweight, and 10.6% of patients was obese. BMI did not show a significant association with ER status, PR status, HER-2 status, lymph node involvement and neoadjuvant chemotherapy regimen. In univariate analysis, overweight and obese patients were significantly less likely to have a pCR compared with normal weight patients (odds ratio [OR] = 0.300; 95% CI, 0.115 to 0.784; p = 0.010). In multivariate analysis, ER negativity was significantly associated with a pCR and pPR to neoadjuvant chemotherapy (OR = 2.987; 95% CI, 1.128 to 7.907; p = 0.028), And there was significant difference in pCR for overweight and obese compared with normal weight patients (OR = 0.304;95% CI, 0.115 to 0.803; p = 0.016). Conclusion This study suggests that higher BMI should be considered to be a factor of worse response to neoadjuvant chemotherapy in patients with operable breast cancer. Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P1-08-22.