title: Is chronic kidney disease an independent risk factor for mortality in breast cancer?
abstract: BACKGROUND
  Chronic kidney disease (CKD) is an independent risk factor for morbidity and mortality in multiple disease processes. However, not much is known about the relationship between breast cancer and CKD. CKD is associated with increased difficulty in breast cancer screening or surveillance due to increased calcifications on mammography. In addition, there is concern regarding the optimization of serum levels of chemotherapeutics in patients with CKD or on hemodialysis. We hypothesized that CKD is an independent risk factor for mortality in patients with breast cancer.
  
  
  METHODS
  A case-matched, retrospective review of a prospectively maintained database was conducted on patients treated for breast cancer at an academic medical center between 1998 and 2011. Glomerular filtration rates (GFRs) were calculated for each patient at the time of diagnosis, and patients with CKD (GFR <60 mL/min) were matched in a 1:2 ratio with patients with GFR >60 mL/min, controlling for age, stage at diagnosis, and race. Primary end points measured were disease-free survival and overall survival. Statistical analysis was performed using Student t-test and Kaplan-Meier.
  
  
  RESULTS
  Of the 1223 total patients, 54 (4%) had CKD. One hundred five patients without CKD were matched for age, stage at diagnosis, and race. Mean GFR among patients with and without CKD were 47.6 and 83.2 mL/min, respectively (P < 0.001). The 5-y overall survival was 77% for patients with CKD and 86% for patients without CKD (P = 0.47). Disease-free survival was 64% and 81%, respectively (P = 0.45).
  
  
  CONCLUSIONS
  Based on our data, CKD does not appear to have a significant impact on outcomes in patients with breast cancer.
authors.affiliation: Department of Surgery, Louisiana State University Health Sciences Center-Shreveport, Shreveport, Louisiana 71130, USA.
authors.forename: Arielle C
authors.initials: AC
authors.lastname: Dubose
authors.forename: Quyen D
authors.initials: QD
authors.lastname: Chu
authors.forename: Benjamin D L
authors.initials: BD
authors.lastname: Li
authors.forename: Roger H
authors.initials: RH
authors.lastname: Kim
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001943:Breast Neoplasms / Q000000981:diagnostic imaging / Q000401:mortality*; D002114:Calcinosis / Q000000981:diagnostic imaging / Q000401:mortality*; D016208:Databases, Factual / Q000706:statistics & numerical data; D018572:Disease-Free Survival; D005260:Female; D005919:Glomerular Filtration Rate; D006801:Humans; D053208:Kaplan-Meier Estimate; D007676:Kidney Failure, Chronic / Q000401:mortality*; D008327:Mammography; D008875:Middle Aged; D009017:Morbidity; D016016:Proportional Hazards Models; D051436:Renal Insufficiency, Chronic / Q000401:mortality*; D012189:Retrospective Studies; D012307:Risk Factors
keywords: Breast cancer; Chronic kidney disease; End-stage renal disease