title: Evaluation of tumor burden after sequential molecular-targeted therapy in patients with metastatic renal cell carcinoma.
abstract: BACKGROUND
  To evaluate the effect of tumor burden on survival in patients with metastatic renal cell carcinoma who are administered sequential molecular-targeted therapy.
  
  
  METHODS
  A total of 68 patients were recruited. Baseline tumor burden at the time of second-line therapy initiation was calculated according to the Response Evaluation Criteria in Solid Tumors v. 1.1. Patients were divided into two subgroups according to the median tumor burden: greater than the median as the high group, lower than the median as the low group. Progression-free survival and overall survival after second-line therapy were analyzed. The effect of tumor burden changes on survival during sequential targeted therapy were also evaluated.
  
  
  RESULTS
  Median second-line tumor burden was 57.7 cm. The patients with high tumor burden had significantly poorer progression-free survival and overall survival, compared to those with low tumor burden (median progression-free survival = 4.36 vs. 8.19 months, P = 0.0119; overall survival = 9.6 vs. 23.5 months, P = 0.0107). For progression-free survival, multivariate analyses revealed that second-line objective response was an independent predictor (P < 0.0001), but second-line tumor burden was not (P = 0.0826). For overall survival, second-line tumor burden and objective response were independent predictors (P = 0.0300 and <0.0001, respectively). Moreover, there was a positive correlation between first- and second-line tumor burden (r2 = 0.460, P < 0.0001), although tumor burden changes between first- and second-line therapies did not affect survival (median progression-free survival, P = 0.812; overall survival, P = 0.415).
  
  
  CONCLUSIONS
  Second-line tumor burden was an independent predictor of overall survival among patients with metastatic renal cell carcinoma after second-line therapy.
authors.affiliation: Department of Urology, Kidney Center, Tokyo Women's Medical University, 8-1 Kawada-cho, Shinjuku-ku, Tokyo162-8666, Japan.
authors.forename: Hiroki
authors.initials: H
authors.lastname: Ishihara
authors.affiliation: Department of Urology, Kidney Center, Tokyo Women's Medical University, 8-1 Kawada-cho, Shinjuku-ku, Tokyo162-8666, Japan.
authors.forename: Tsunenori
authors.initials: T
authors.lastname: Kondo
authors.affiliation: Department of Urology, Kidney Center, Tokyo Women's Medical University, 8-1 Kawada-cho, Shinjuku-ku, Tokyo162-8666, Japan.
authors.forename: Kazuhiko
authors.initials: K
authors.lastname: Yoshida
authors.affiliation: Department of Urology, Kidney Center, Tokyo Women's Medical University, 8-1 Kawada-cho, Shinjuku-ku, Tokyo162-8666, Japan.
authors.forename: Kenji
authors.initials: K
authors.lastname: Omae
authors.affiliation: Department of Urology, Kidney Center, Tokyo Women's Medical University, 8-1 Kawada-cho, Shinjuku-ku, Tokyo162-8666, Japan.
authors.forename: Toshio
authors.initials: T
authors.lastname: Takagi
authors.affiliation: Department of Urology, Kidney Center, Tokyo Women's Medical University, 8-1 Kawada-cho, Shinjuku-ku, Tokyo162-8666, Japan.
authors.forename: Junpei
authors.initials: J
authors.lastname: Iizuka
authors.affiliation: Department of Urology, Kidney Center, Tokyo Women's Medical University, 8-1 Kawada-cho, Shinjuku-ku, Tokyo162-8666, Japan.
authors.forename: Hirohito
authors.initials: H
authors.lastname: Kobayashi
authors.affiliation: Department of Urology, Kidney Center, Tokyo Women's Medical University, 8-1 Kawada-cho, Shinjuku-ku, Tokyo162-8666, Japan.
authors.forename: Kazunari
authors.initials: K
authors.lastname: Tanabe
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002292:Carcinoma, Renal Cell / Q000188:drug therapy*; D018572:Disease-Free Survival; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D058990:Molecular Targeted Therapy / Q000379:methods*; D012189:Retrospective Studies; D016896:Treatment Outcome; D047368:Tumor Burden / Q000235:genetics*
keywords: biomarker; metastatic renal cell carcinoma; molecular-targeted therapy; predictor; second-line; tumor burden