Is adipose tissue metabolic activity a predictor of pathological responses to neoadjuvant treatment in breast cancer

Prediction of the pathologic response to neoadjuvant chemotherapy (NAC) in patients with locally advanced breast cancer is essential for optimal treatment strategy. The current approach of adjuvant or neoadjuvant treatment is based on the molecular subtype. Obesity may have affected chemotherapy response. This study aims to evaluate the relationship between metabolic activity of adipose tissue (AT) and pathological responses to NAC. And to define the association with body mass index (BMI) and metabolic parameters of standardized uptake value (SUV) of adipose tissue measured by positron emission computed tomography (PET/CT).

One-hundred and sixteen consecutive patients with stage II and III breast cancer who underwent PET/CT before receiving NAC, were evaluated in the study. Metabolic parameters of visceral adipose tissue (VAT-SUV), subcutaneous adipose tissue (SAT-SUV), and calculated SUV of visceral-to-subcutaneous ratio (V/S-ratio) were regarded. The relationship between SUV of AT and pathologic response was evaluated from medical records retrospectively.

Univariate-analysis revealed that good pathological response was significantly associated with clinical stage (P<.001), HER-2 positivity (P<.001), VAT-SUV (P=.037), VAT-density (P=.043) and V/S-ratio (P=.003). In multivariate-analysis clinical stage, HER-2 positivity and V/S-ratio were found to have statistically effect on pathological response. VAT-volume (P<.001), VAT-SUV (P=.016), SAT-volume (P<.001) and SAT-SUV (P<.001) has positive correlation with BMI value. On the other hand, V/S-ratio (P=.039) and SAT-density (P=.003) has negative correlation with BMI.

Metabolic activity of AT is associated with BMI and effected chemotherapy responses. LowV/S ratio was associated with high BMI and poor pathological response to NAC. V/S ratio may be a useful marker for the prediction of NAC responses.