The effect of neoadjuvant chemotherapy on short-term outcomes in breast surgery: A propensity score adjusted analysis of NSQIP data.

Abstract

115 Background: Neoadjuvant chemotherapy (NAC) is increasingly used in the treatment of breast cancer. The primary objective of this study was to determine whether administration of NAC increased the proportion of overall 30-day post-operative complications among patients undergoing surgery for invasive breast cancer. Methods: An analysis of the American College of Surgeons, National Surgical Quality Improvement Program (ACS-NSQIP) participant user files from 2005-2012 was performed. Patients undergoing surgery for invasive breast cancer were included; those with high-risk comorbidities or concurrent surgery were excluded. The primary outcome was a composite of overall 30-day post-operative complications. A propensity score was calculated and a propensity score adjusted multivariable logistic regression model was used to determine the independent effect of NAC on overall 30-day complications. Results: In the study period67,685 patients having surgery for invasive breast cancer were identified; of those, 3,624 (5.5%) received NAC. The rate of NAC use within this cohort increased from 5.5% to 10.2%. Patients who received NAC were: younger and had fewer medical comorbidities, but, were more likely to receive neoadjuvant radiation and undergo bilateral surgery. On unadjusted analysis, patients receiving NAC had significantly more post-operative complications than those not receiving NAC (4.9% vs. 3.7%, p = 0.0003) mainly due to infection and bleeding. However, after adjusting for confounders by propensity score adjusted multivariable regression, there was no longer a significant difference in overall 30-day post-operative complications between those receiving NAC versus not (odds ratio 1.16 [95%CI: 0.98, 1.36]). Conclusions: This is the largest study to examine the effect of NAC on post-operative complications in patients undergoing surgery for invasive breast cancer. The receipt of NAC does not impart a significantly increased risk of post-operative complications in this patient population.