title: Is the eGFR formula adequate for evaluating renal function before chemotherapy in patients with urogenital cancer? A suggestion for clinical application of eGFR formula.
abstract: BACKGROUND
  Accurate evaluation of renal function is required before cancer chemotherapy. Various kinds of formula have been developed for estimating creatinine clearance (Ccr) or glomerular filtration rate (GFR) conveniently. We retrospectively examined the reliability of the GFR estimating formula using the renal function data in cancer chemotherapy.
  
  
  METHODS
  Clinical data of 12 patients with urogenital cancer from 1998 to 2013 in Saga University Hospital were reviewed. Patients were treated with 6-21 (median 10.5) courses of chemotherapy and those patients underwent 9-29 (median 14.5) times of 24hrCcr tests before and during chemotherapy. We compared estimated GFR (eGFR) with 24hrCcr. In addition, we developed a novel method to estimate the Ccr using the patient-inherent 24hrCcr/eGFR ratio, which is calculated from initial 3 or 4 determinations of 24hrCcr and the corresponding eGFR. Those estimated Ccrs were also compared with 24hrCcr.
  
  
  RESULTS
  The dissociation between 24hrCcr and eGFR was not constant, and a large dissociation was observed in some cases. The newly devised estimated Ccr demonstrated less dissociation from 24hrCcr compared with eGFR.
  
  
  CONCLUSIONS
  The eGFR formula is not adequate for the clinical use in cancer chemotherapy. The absolute value of eGFR is not reliable, but clinical use of eGFR as relative value seems to be acceptable. To avoid troublesome 24hrCcr measurement in long-term cancer chemotherapy, eGFR formula can be used for estimating Ccr in combination with the specific inherent 24hrCcr/eGFR ratio, which is obtained from 3 or 4 times of actual 24hrCcr measurements.
authors.affiliation: Department of Urology, Faculty of Medicine, Saga University, 5-1-1 Nabeshima, Saga, 849-8501, Japan, uozumi@cc.saga-u.ac.jp.
authors.forename: Jiro
authors.initials: J
authors.lastname: Uozumi
authors.forename: Mitsuru
authors.initials: M
authors.lastname: Noguchi
authors.forename: Yuji
authors.initials: Y
authors.lastname: Tokuda
authors.forename: Shohei
authors.initials: S
authors.lastname: Tobu
authors.forename: Kazuma
authors.initials: K
authors.lastname: Udo
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Kakinoki
authors.forename: Saya
authors.initials: S
authors.lastname: Kurata
authors.forename: Maki
authors.initials: M
authors.lastname: Nanri
authors.forename: Yuka
authors.initials: Y
authors.lastname: Ichibagase
authors.forename: Kohei
authors.initials: K
authors.lastname: Takahara
mesh_terms: D000328:Adult; D000368:Aged; D000970:Antineoplastic Agents / Q000009:adverse effects*; D003404:Creatinine / Q000097:blood / Q000652:urine; D005260:Female; D005919:Glomerular Filtration Rate; D006801:Humans; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D014565:Urogenital Neoplasms / Q000188:drug therapy*; D055815:Young Adult
chemical_list: D000970:Antineoplastic Agents; D003404:Creatinine