Body mass index (BMI) is a predictor for response to neoadjuvant chemotherapy in women with localized breast cancer aged 35 years or younger

Abstract

600 Objective: High BMI has been linked to poor outcome in patients with breast cancer. Evidence relating to obesity as a predictor for prognosis in premenopausal patients have been controversial. The aim of this study is to evaluate the impact of BMI on response to treatment and recurrence following neoadjuvant CT in young patients with breast cancer.> Method: In this study, we analyzed the impact of BMI on the outcome of 111 patients who received anthracycline and/or taxane-based neoadjuvant CT for localized breast cancer. Median age at diagnosis was 32 (22–35). Fifty six patients (50.5%) had stage II and 54 had stage III disease. Hormonal receptors were positive in 65 patients (58.6%) and HER-2/neu was overexpressed in 29 patients (26.1%). Pathologic evaluation revealed that 27 patients had (24.3%) had downstaging in axillary LN, while 13 (11.7%) showed complete regression both in the primary tumor and axillary LN following completion of chemotherapy. Patients were grouped in quartiles of BMI calculated prior to initiation of chemotherapy. >Results: After a median follow-up period of 26 months (3–94), 39 patients experienced recurrence (35.1%). Median overall (OS) and progression-free (PFS) survival rates at 5 years were 62.6 %±9.7 and 38.6%±8.1, respectively.Multivariate Cox regression analysis revealed pathologic response (OR:2.3, p=0.04) and recurrence (OR:108.7, p:0.047) as significant independent prognostic factors for PFS and OS, respectively. Lowest BMI quartile was significantly associated with lack of pathologic response to neoadjuvant chemotherapy compared to those with a larger body size (OR: 3.9, p=0.009). Conclusion: Obesity did not correlate with prognosis in young, premenopausal women with early breast cancer. However, patients within the lowest BMI quartile were less likely to respond to neoadjuvant anthracycline or taxane-based chemotherapy. Unresponsiveness to CT may account for the poor outcome in young premenopausal patients compared to older patients. The role of BMI on the outcome of this subset of patients should be validated further by larger prospective studies. No significant financial relationships to disclose.