Risk Factors for Postoperative Bleeding Following Breast Cancer Surgery: A Nationwide Database Study of 477,108 Cases in Japan.

ABSTRACT

BACKGROUND: Although postoperative bleeding is a common and serious complication in breast cancer surgery, the risk factors remain unclear. Therefore, we examined the risk factors using a Japanese nationwide database. METHODS: Patients who underwent breast cancer surgery between July 2010 and March 2020 were identified from a Japanese nationwide database. Multivariable analyses for 47 candidate risk factors (4 patient characteristics, 32 comorbidities, 5 tumor characteristics, 3 preoperative drug uses, and 3 surgical procedures) were conducted to investigate risk factors associated with postoperative bleeding requiring reoperation. Two sensitivity analyses were conducted an analysis for postoperative bleeding with or without reoperation and an analysis for patients who underwent total mastectomy without breast reconstruction. RESULTS: Among the 477,108 patients included, 7048 (1.5%) developed postoperative bleeding and 2357 (0.5%) underwent reoperation for postoperative bleeding. Male sex, old age, body mass index ≥ 25.0 kg/m2, several comorbidities (deficiency anemia, cardiac arrhythmias, hypertension, liver disease, psychoses, and valvular disease), preoperative heparin use, and several procedures were identified as risk factors. Deficiency anemia showed the highest odds ratio among the risk factors (4.41 [95% confidence interval, 3.63-5.36]). High odds ratios were also observed in total mastectomy (2.32 [2.10-2.56]), flap reconstruction (1.93 [1.55-2.40]), and preoperative heparin use (1.64 [1.26-2.14]). The results corresponded with the sensitivity analyses. CONCLUSIONS: This study identified several risk factors for postoperative bleeding in breast cancer surgery, such as high body mass index, anemia, cardiovascular diseases, liver diseases, psychoses, preoperative heparin use, and surgical procedures.