title: Hyponatremia as a powerful prognostic predictor for Japanese patients with clear cell renal cell carcinoma treated with a tyrosine kinase inhibitor.
abstract: BACKGROUND
  We aimed to evaluate the prognostic significance of hyponatremia in patients with metastatic clear cell renal cell carcinoma (RCC) treated with a tyrosine kinase inhibitor (TKI).
  
  
  METHODS
  This study included a total of 209 consecutive Japanese patients undergoing radical nephrectomy who were subsequently treated with either sunitinib or sorafenib as a first-line therapy for metastatic clear cell RCC. In this series, normal natremia and hyponatremia prior to the introduction of TKI was defined as a serum sodium level >136 and ≤136 mEq/L, respectively.
  
  
  RESULTS
  Patients were classified into 165 (78.9 %) with normal natremia and 44 (21.1 %) with hyponatremia. Progression-free survival (PFS) in the hyponatremia group (median 10.0 months) was significantly poorer than that in the normal natremia group (median 28.4 months). Overall survival (OS) in the hyponatremia group (median 20.9 months) was significantly poorer than that in the normal natremia group (median 38.5 months). Multivariate analyses identified hyponatremia, in addition to the existence of sarcomatoid components in radical nephrectomy specimens, high serum C-reactive protein levels, and low serum albumin levels, as poor prognostic factors for both PFS and OS. There were significant differences in both PFS and OS according to the number of these 4 independent risk factors that were positive (negative for any risk factors vs positive for 1 or 2 risk factors vs positive for 3 or 4 risk factors).
  
  
  CONCLUSIONS
  Hyponatremia appears to be one of the most powerful prognostic predictors in Japanese patients treated with a TKI as a first-line agent against metastatic clear cell RCC.
authors.affiliation: Division of Urology, Kobe University Graduate School of Medicine, 7-5-1 Kusunoki-cho, Chuo-ku, Kobe, 650-0017, Japan.
authors.forename: Junya
authors.initials: J
authors.lastname: Furukawa
authors.forename: Hideaki
authors.initials: H
authors.lastname: Miyake
authors.forename: Yuji
authors.initials: Y
authors.lastname: Kusuda
authors.forename: Masato
authors.initials: M
authors.lastname: Fujisawa
mesh_terms: D000368:Aged; D000970:Antineoplastic Agents / Q000627:therapeutic use*; D002097:C-Reactive Protein / Q000378:metabolism; D002292:Carcinoma, Renal Cell / Q000150:complications / Q000556:secondary / Q000628:therapy*; D017024:Chemotherapy, Adjuvant; D018572:Disease-Free Survival; D005260:Female; D006801:Humans; D007010:Hyponatremia / Q000097:blood / Q000150:complications*; D007211:Indoles / Q000627:therapeutic use*; D007564:Japan; D007680:Kidney Neoplasms / Q000150:complications / Q000473:pathology / Q000628:therapy*; D008297:Male; D008875:Middle Aged; D009392:Nephrectomy; D009536:Niacinamide / Q000031:analogs & derivatives* / Q000627:therapeutic use; D010671:Phenylurea Compounds / Q000627:therapeutic use*; D047428:Protein Kinase Inhibitors / Q000627:therapeutic use; D011758:Pyrroles / Q000627:therapeutic use*; D012189:Retrospective Studies; D012307:Risk Factors; D012709:Serum Albumin / Q000378:metabolism; D012964:Sodium / Q000097:blood; D000077157:Sorafenib; D000077210:Sunitinib; D015996:Survival Rate
chemical_list: D000970:Antineoplastic Agents; D007211:Indoles; D010671:Phenylurea Compounds; D047428:Protein Kinase Inhibitors; D011758:Pyrroles; D012709:Serum Albumin; D009536:Niacinamide; D002097:C-Reactive Protein; D012964:Sodium; D000077157:Sorafenib; D000077210:Sunitinib