Comparisons of postoperative outcomes after breast cancer surgery in patients with and without renal replacement therapy: a matched-pair cohort study using a Japanese nationwide inpatient database

Background: Although patients receiving renal replacement therapy (RRT) have more comorbidities and higher mortality and morbidity risks than the general population, surgery during breast cancer treatment is crucial because of limitations in anticancer agents for patients with renal insufficiency. We aimed to compare the short-term postoperative outcomes between patients with and without RRT.

Methods: Patients who underwent surgery for stages 0-III breast cancer between July 2010 and March 2017 were retrospectively identified in a Japanese nationwide inpatient database and divided into those with RRT (RRT group, n = 1547) and those without RRT (control group, n = 364,047). We generated a 1:4 matched-pair cohort matched for age, institution, and fiscal year at admission. We conducted multivariable regression analyses to compare postoperative complications, 30-day readmission, and anesthesia duration between the two groups.

Results: The RRT group was more likely to have comorbidities (95.0% vs. 24.1%) and undergo total mastectomy (64.2% vs. 47.0%) than the control group. The RRT group was not significantly associated with complications (odds ratio 1.18; 95% confidence interval [CI] 0.89-1.56) and 30-day readmission (odds ratio 0.88; 95% CI 0.65-1.18), but was associated with shorter anesthesia duration (difference, - 6.8 min; 95% CI - 10.7 to - 3.0 min) compared with the control group.

Conclusions: The matched-pair cohort analyses revealed no significant differences in postoperative complications after breast cancer surgery between patients with and without RRT. Breast cancer surgery in patients with RRT may be as safe as that in patients without RRT, if comorbidities other than chronic renal failure are adequately addressed.