The influence of weight change on the response to neoadjuvant chemotherapy (NAC) among adult Filipino patients with breast cancer remains unclear. Currently, there has been increasing evidence that weight gain during NAC is associated with increased recurrence risk and decreased survival. This study aimed to investigate this relationship and identify significant predictors of pathologic complete response (pCR), overall survival (OS) and disease-free survival (DFS).

This is a retrospective study using data from 52 female patients who received NAC for stage II or III breast cancer and had complete records of weight before and after NAC. Significant predictors of pCR such as host factors and tumor characteristics and associations between weight change and pCR, OS and DFS were examined using univariate and multivariable logistic regression analyses.

The average weight of all patients before NAC was 57.0 kg while the average weight of all patients after NAC was 59.5 kg. The average BMI of all patients before NAC was 25.8 kg/m2. In total, 29 patients (55.8%) were classified in the overweight/obese (OW/OB) group, and the rest were classified in the normal weight/underweight (NW/UW) group. The pCR rate was 51.3% in the OW/OB group versus 48.7% in the NW/UW group (p = 0.11). Initial BMI was a significant factor for achieving pCR (hazard ratio, 3.85; 95% confidence interval [CI], 1.72-8.60, p = 0.001), suggesting that a higher initial BMI was associated with an increased likelihood of achieving pCR. Initial BMI was also an independent prognostic factor for OS (p = 0.0006) and DFS (p = 0.0005). On the other hand, no significant correlation was seen between pCR rates as well as OFS and DFS (p = 0.0551) among patients whose weight changed during the course of treatment.

These findings suggest that while initial weight may significantly predict pCR rates and affect DFS and OS, weight change during treatment may not be as influential. Further research is needed to validate these findings in more diverse and larger patient populations.