engleski

Impact of increased body mass index on neoadjuvant treatment outcome in breast cancer patients

Obesity is a major health issue. It has been associated with increased risk of breast cancer (BC) and poorer prognosis. There is evidence that obese patients are less likely to achieve pathological complete response (pCR) to neoadjuvant chemotherapy (NCT). Although the underlying mechanism is unknown, it is suggested that increased circulating levels of estrogen, insulin, insulin-like growth factor and other hormonal factors in obese patients may promote proliferation of breast cancer cells. The aim of this study was to determine the impact of increased body mass index (BMI) on pathological complete response in patients with primary BC treated with neoadjuvant chemotherapy. Retrospectively we identified 117 patients with breast carcinoma treated with NCT at University Hospital for Tumors in Zagreb. 79 patients fi nished neoadjuvant chemotherapy and underwent surgery so theirs data were further analyzed. Patients were categorized according to BMI: normal weight (<25 kg/m2), overweight (25-30 kg/m2) and obese (>30 kg/m2). Pathological complete response (pCR) was defined by absence of invasive cancer in resected breast and axillary tissue. Pathological complete response (pCR) was achieved in 24% breast cancer patients treated with NCT (47% luminal B, 53% hormone receptor negative BC). 65% of patients had BMI> 25 kg/m2, from which 29% had BMI >30 kg/m2. pCR was achieved in 14% of patients with BMI >25 kg/m2, in group with s BMI <25 kg/m2 pCR was achieved in 43% of patients. Subgroup analysis showed that patients with BMI> 25 kg/m2 were mostly postmenopausal (90%) and they presented more frequently with luminal B cancer (65%). Patients with BMI>25 were less likely to achieve a pCR to NCT compared with patients with BMI<25. Obese patients present more frequently with larger, locally advanced breast tumors, so they are more frequently candidates for NKT. Further investigation of mechanism of infl uence of BMI on treatment outcome is needed. Suboptimal dose of chemotherapy for obese patients may also contribute to diminished efficacy of NCT.

obesity, breast cancer, neoadjuvant chemotherapy, outcome

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