Patients who received neoadjuvant chemotherapy within 30 days prior to breast cancer surgery did not appear to be at increased risk for overall postoperative complications, according to a study presented at the 2015 Breast Cancer Symposium.¹

“Although on unadjusted analysis there were more complications in the neoadjuvant-chemotherapy cohort, this difference was negated when controlling for baseline differences with a propensity-score adjusted multivariate model,” said Erin Cordeiro, MD, a surgeon at The Ottawa Hospital in Ontario, Canada. “There was no difference in the overall 30-day postoperative complication rate between patients treated with neoadjuvant chemotherapy vs not.”

“Surgeons should not feel that they have to wait more than 4 weeks following chemotherapy to perform breast cancer surgery safely,” she added.

Conventionally, neoadjuvant chemotherapy has been directed at advanced, inoperable breast cancers; however, in modern times, its use has expanded to include even small, early-stage cancers.

“The indications for neoadjuvant chemotherapy are increasing,” Dr. Cordeiro explained. “Patients with triple-negative disease as well as HER2-positive disease have increased rates of pathologic complete response, and many clinicians are increasing their use of neoadjuvant chemotherapy to these populations.”

A recent study of the National Cancer Database indicated that in 2011, 20% of all patients with breast cancer received neoadjuvant chemotherapy (up from 14% in 2006). And yet, as Dr. Cordeiro noted, there are still concerns among surgeons regarding the toxic side effects of chemotherapy.

“Many surgeons feel that there may be an increase in postoperative complications when patients undergo surgery in the neoadjuvant chemotherapy setting,” said Dr. Cordeiro. “For this reason, some surgeons are waiting 4 to 6 weeks following chemotherapy before performing surgery.”

Study Design

To determine whether there is a difference in the proportion of overall 30-day postoperative complications, researchers analyzed data from the American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP), a large database incorporating over 600 hospitals in the United States, Canada, and ­Europe.

All patients undergoing surgery for invasive breast cancer from 2005 to 2012 were included in the study, excluding those with high-risk comorbidities, metastatic disease, synchronous high-risk nonbreast surgery, or a missing neoadjuvant chemotherapy variable.

After performing univariate and bivariate analyses, a propensity score was calculated based on the probability of the patient receiving neoadjuvant chemotherapy. Variables included in the propensity score were patient age; whether the patient had diabetes, chronic obstructive pulmonary disease, or hypertension; whether the patient underwent bilateral surgery; and the year of the surgery.

Results

Of the 67,685 patients who underwent breast cancer surgery between 2005 and 2012 (and met inclusion criteria), 3,624 received neoadjuvant chemotherapy (5.4%). “Interestingly,” said Dr. Cordeiro, “a significant proportion of patients who received neoadjuvant chemotherapy had bilateral surgery, as compared to those who did not.”

“It should also be noted,” she added, “that the utilization of neoadjuvant chemotherapy increased from just over 5% in 2005 to just over 10% in 2012.”

Although an unadjusted analysis of overall postoperative complication rate revealed a significantly higher percentage of complications in patients receiving neoadjuvant chemotherapy compared with those who did not (5% vs 3.7%), this discrepancy was resolved after controlling for differences in initial baseline demographics.

“When looking at the independent effect of neoadjuvant chemotherapy, there actually was no difference in the group that received neoadjuvant chemotherapy vs surgery upfront,” Dr. Cordeiro concluded. “Neoadjuvant chemotherapy did not turn out to be an independent predictor of postoperative complications.”

However, other well-known predictors of postoperative complications were statistically significant, such as having a higher body mass index, being a smoker, having a higher American Society of Anesthesiologists classification, having a bleeding disorder, and having a longer operative time. ■

Disclosure: Dr. Cordeiro reported no potential conflicts of interest.

Reference

1. Cordeiro E, Arnaout A, Cil T: The effect of neoadjuvant chemotherapy on short-term outcomes in breast cancer surgery: A propensity score adjusted analysis of NSQIP data. 2015 Breast Cancer Symposium. Abstract 115. Presented September 25, 2015.