Background: Four percent of breast cancer patients present with metastatic disease. To date, no one has examined whether these patients are at higher risk of postoperative complications. The objective of this study was to determine morbidity and mortality associated with breast surgery in the metastatic setting.
Methods: We analyzed the American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) database, including breast cancer patients undergoing primary breast surgery from 2005 to 2012. Patients with bilateral surgery or severe comorbidities were excluded. Multivariable logistic regression was performed to determine the independent effect of metastatic breast cancer on postoperative morbidity and mortality.
Results: We identified 68,316 patients who underwent breast surgery for invasive breast cancer; 1,031 (1.5 %) had metastatic disease. The 30-day unadjusted morbidity was significantly higher in the metastatic cohort (7.5 vs. 3.7 %; p < 0.001), as was the all-cause 30-day mortality (1.8 vs. 0.06 %; p < 0.001). The metastatic cohort was more likely to experience an: infectious, respiratory, thromboembolic, cardiac, or bleeding complication than non-metastatic patients. However, preoperative chemo- and radiation therapy did not contribute to an overall increased complication rate. The adjusted odds ratio for postoperative complications in the setting of metastatic disease was 1.6 (95 % confidence limit 1.2-2.1).
Conclusions: This is the first study documenting the morbidity and mortality associated with breast surgery in metastatic breast cancer. The 30-day morbidity and mortality in this population is higher than in patients with stage I-III disease. Although the complication rate is increased, operating on the primary in metastatic breast cancer is relatively safe.