title: Tumor size is a potential predictor of response to tyrosine kinase inhibitors in renal cell cancer.
abstract: OBJECTIVE
  To investigate the correlations between the initial tumor size and size reduction rate in patients treated with targeted agents. To select the patients who can benefit the most from treatment with targeted agents, it will be necessary to find a tumor characteristic that predicts their effectiveness.
  
  
  METHODS
  The data from 139 metastatic and 16 primary lesions treated with the targeted agents were retrospectively analyzed. They consisted of 86 sunitinib-treated and 69 sorafenib-treated lesions in 54 patients with metastatic renal cell carcinoma who had undergone treatment from April 2008 to July 2010. The relationship between the longest tumor diameter at baseline and the rate of reduction in tumor size was assessed using the Spearmancorrelation test.
  
  
  RESULTS
  A linear, moderate to strong association between the initial tumor size and tumor size reduction rate was shown (correlation coefficient -0.441, P < .001). When these tumors were divided into 2 groups at the threshold value (23.95 mm), which was decided by the receiver operating characteristic curve analysis, the smaller tumors demonstrated a significantly greater size reduction than the larger tumors according to the Mann-Whitney U test (P < .001). Both univariate and multivariate linear regression analyses revealed that only the initial tumor size was associated with the rate of reduction in individual tumors (P < .001).
  
  
  CONCLUSIONS
  The initial tumor size was a good predictor of the tumor size reduction. This simple observation could be useful for physicians who treat patients with metastatic renal cell carcinoma. In addition, in assessing clinical trials of targeted agents for metastatic renal cell carcinoma using the ResponseEvaluation Criteria in Solid Tumors, perhaps this association should be considered.
authors.affiliation: Department of Urology, Cancer Institute Hospital, Japanese Foundation for Cancer Research, Ariake, Tokyo, Japan.
authors.forename: Takeshi
authors.initials: T
authors.lastname: Yuasa
authors.forename: Shinji
authors.initials: S
authors.lastname: Urakami
authors.forename: Shinya
authors.initials: S
authors.lastname: Yamamoto
authors.forename: Junji
authors.initials: J
authors.lastname: Yonese
authors.forename: Kenji
authors.initials: K
authors.lastname: Nakano
authors.forename: Makoto
authors.initials: M
authors.lastname: Kodaira
authors.forename: Shunji
authors.initials: S
authors.lastname: Takahashi
authors.forename: Kiyohiko
authors.initials: K
authors.lastname: Hatake
authors.forename: Kentaro
authors.initials: K
authors.lastname: Inamura
authors.forename: Yuichi
authors.initials: Y
authors.lastname: Ishikwa
authors.forename: Iwao
authors.initials: I
authors.lastname: Fukui
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000970:Antineoplastic Agents / Q000008:administration & dosage / Q000627:therapeutic use*; D001557:Benzenesulfonates / Q000008:administration & dosage / Q000627:therapeutic use*; D002292:Carcinoma, Renal Cell / Q000188:drug therapy* / Q000473:pathology* / Q000601:surgery; D003131:Combined Modality Therapy; D005260:Female; D006801:Humans; D007211:Indoles / Q000008:administration & dosage / Q000627:therapeutic use*; D007680:Kidney Neoplasms / Q000188:drug therapy* / Q000473:pathology* / Q000601:surgery; D008297:Male; D008875:Middle Aged; D009392:Nephrectomy; D009536:Niacinamide / Q000031:analogs & derivatives; D010671:Phenylurea Compounds; D047428:Protein Kinase Inhibitors / Q000627:therapeutic use*; D011505:Protein-Tyrosine Kinases / Q000037:antagonists & inhibitors; D011725:Pyridines / Q000008:administration & dosage / Q000627:therapeutic use*; D011758:Pyrroles / Q000008:administration & dosage / Q000627:therapeutic use*; D012189:Retrospective Studies; D000077157:Sorafenib; D000077210:Sunitinib; D016896:Treatment Outcome
chemical_list: D000970:Antineoplastic Agents; D001557:Benzenesulfonates; D007211:Indoles; D010671:Phenylurea Compounds; D047428:Protein Kinase Inhibitors; D011725:Pyridines; D011758:Pyrroles; D009536:Niacinamide; D000077157:Sorafenib; D011505:Protein-Tyrosine Kinases; D000077210:Sunitinib