PATIENTS AND METHODS: We retrospectively examined serial bone scans from patients with castration-resistant metastatic prostate cancer (CRMPC) enrolled in four clinical trials. We calculated BSI at baseline and at 3 and 6 months on treatment and performed univariate and bivariate analyses of PSA, BSI, and survival.
RESULTS: Eighty-eight patients were scanned, 81 of whom have died. In the univariate analysis, the log percent change in BSI from baseline to 3 and 6 months on treatment prognosticated for survival (hazard ratio [HR], 2.44; P = .0089 and HR, 2.54; P < .001, respectively). A doubling in BSI resulted in a 1.9-fold increase in risk of death. Log percent change in PSA at 6 months on treatment was also associated with survival (HR, 1.298; P = .013). In the bivariate analysis, change in BSI while adjusting for PSA was prognostic at 3 and 6 months on treatment (HR, 2.368; P = .012 and HR, 2.226; P = .002, respectively), but while adjusting for BSI, PSA was not prognostic.
CONCLUSION: These data furnish early evidence that on-treatment changes in BSI are a response indicator and support further exploration of bone scintigraphy as an imaging biomarker in CRMPC.
Written by:
Dennis ER, Jia X, Mezheritskiy IS, Stephenson RD, Schoder H, Fox JJ, Heller G, Scher HI, Larson SM, Morris MJ. Are you the author?
Memorial Sloan-Kettering Cancer Center; Weill Medical College of Cornell University, New York, NY.
Reference: J Clin Oncol. 2012 Jan 9. Epub ahead of print.
doi: 10.1200/JCO.2011.36.5791
PubMed Abstract
PMID: 22231045
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