title: A new equation for estimating glomerular filtration rate in cancer patients.
abstract: BACKGROUND
  The accuracy of the Cockcroft-Gault (CG) equation, the Modification of Diet in Renal Disease (MDRD) equation and the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation in cancer patients was tested. An equation for estimating glomerular filtration rate (GFR) was created that was adapted to cancer patients.
  
  
  METHODS
  Data from 641 oncology patients referred for (51)Cr-EDTA measurements were included. Factors that may affect GFR, i.e. gender, hypertension, diabetes, non-steroid anti-inflammatory drugs (NSAID), exposure to chemotherapy, age, weight, height, BMI, body surface area and creatinine value were correlated to (51)Cr-EDTA-measured GFR. The significant factors were then included in a multiple regression analysis correlated to the measured GFR (mGFR).
  
  
  RESULTS
  The equation of log10 (GFR; ml/min/1.73 m2) = 2.36-0.33*log10 (age) - 0.78*log10 (creatinine) + 0.87*log10 (weight) - 0.03*NSAID*log10 (creatinine) + gender (1 = female, 0 = male)*(0.05*NSAID - 0.003*BMI) was generated. Expressed as a mean (standard deviation) of mGFR <60 ml/min/1.73 m2, this equation, the 'New Equation', overestimated GFR by 26 (33)%, while CG, MDRD and CKD-EPI overestimated GFR by 26 (40)%, 32 (42)% and 48 (47)%, respectively. For mGFR ≥60 ml/min/1.73 m2, the New Equation underestimated GFR by only 3 (16)%, while CG, MDRD and CKD-EPI overestimated GFR by 12 (25)%, 10 (26)% and 5 (23)%, respectively.
  
  
  CONCLUSIONS
  This study describes a novel equation with a higher accuracy than other commonly used GFR equations for estimating GFR in cancer patients.
authors.affiliation: Department of Oncology, Sahlgrenska University Hospital and Department of Pharmacology, Sahlgrenska Academy, Göteborg University, Göteborg, Sweden.
authors.forename: Daniel
authors.initials: D
authors.lastname: Giglio
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000465:Algorithms; D000886:Anthropometry; D019540:Area Under Curve; D002860:Chromium Radioisotopes / Q000737:chemistry; D015331:Cohort Studies; D054697:Cytostatic Agents / Q000627:therapeutic use / Q000633:toxicity; D004492:Edetic Acid / Q000737:chemistry / Q000378:metabolism; D005260:Female; D005919:Glomerular Filtration Rate; D006801:Humans; D007472:Iohexol / Q000378:metabolism; D007668:Kidney / Q000187:drug effects / Q000502:physiology; D007677:Kidney Function Tests; D008297:Male; D008875:Middle Aged; D009369:Neoplasms / Q000188:drug therapy / Q000473:pathology*; D012372:ROC Curve; D012189:Retrospective Studies; D055815:Young Adult
chemical_list: D002860:Chromium Radioisotopes; D054697:Cytostatic Agents; D007472:Iohexol; D004492:Edetic Acid