Major surgical postoperative complications and survival in breast cancer: Swedish population-based register study in 57 152 women

BACKGROUND: Postoperative complications may activate prometastatic systemic pathways through tissue damage, wound healing, infection, and inflammation. Postoperative complications are associated with inferior survival in several types of cancer. The aim was to determine the association between postoperative complications and survival in breast cancer. METHODS: This population-based cohort included women operated for T1–3 N0–3 M0 invasive breast cancer in Sweden from 2008 to 2017. Only major surgical postoperative complications leading to readmission and/or reoperation within 30 days were considered. Main outcomes were overall survival (OS) and breast cancer-specific survival (BCSS). Prospectively collected nationwide register data were used. Multivariable Cox models were adjusted for clinical and socioeconomic confounders and co-morbidity. RESULTS: Among 57 152 women, major surgical postoperative complications were registered for 1854 patients. Median follow-up was 6.22 (0.09–11.70) years. Overall, 9163 patients died, and 3472 died from breast cancer. Major surgical postoperative complications were more common after mastectomy with or without immediate reconstruction (7.3 and 4.3 per cent respectively) than after breast-conserving surgery (2.3 per cent). Unadjusted 5-year OS and BCSS rates were 82.6 (95 per cent c.i. 80.8 to 84.5) and 92.1 (90.8 to 93.5) per cent respectively for women with a major surgical postoperative complication, and 88.8 (88.6 to 89.1) and 95.0 (94.8 to 95.2) per cent for those without a complication (P < 0.001). After adjustment, all-cause and breast cancer mortality rates remained higher after a major surgical postoperative complication (OS: HR 1.32, 95 per cent c.i. 1.15 to 1.51; BCSS: HR 1.31, 1.04 to 1.65). After stratification for type of breast surgery, this association remained significant only for women who had mastectomy without reconstruction (OS: HR 1.41, 1.20 to 1.66; BCSS: HR 1.36, 1.03 to 1.79). CONCLUSION: Major surgical postoperative complications are associated with inferior survival, especially after mastectomy. These results underline the importance of surgical de-escalation.