Categorical versus continuous circulating tumor cell enumeration as early surrogate marker for therapy response and prognosis during docetaxel therapy in metastatic prostate cancer patients.

Thalgott, Mark; Rack, Brigitte; Eiber, Matthias; Souvatzoglou, Michael; Heck, Matthias M; Kronester, Caroline; Andergassen, Ulrich; Kehl, Victoria; Krause, Bernd J; Gschwend, Jürgen E; Retz, Margitta; Nawroth, Roman

doi:10.1186/s12885-015-1478-4

journal article

Title:: Categorical versus continuous circulating tumor cell enumeration as early surrogate marker for therapy response and prognosis during docetaxel therapy in metastatic prostate cancer patients.
Document type:: Clinical Trial; Journal Article; Article
Author(s):: Thalgott, Mark; Rack, Brigitte; Eiber, Matthias; Souvatzoglou, Michael; Heck, Matthias M; Kronester, Caroline; Andergassen, Ulrich; Kehl, Victoria; Krause, Bernd J; Gschwend, Jürgen E; Retz, Margitta; Nawroth, Roman
Abstract:: Circulating tumor cell (CTCs) counts might serve as early surrogate marker for treatment efficacy in metastatic castration-resistant prostate cancer (mCRPC) patients. We prospectively assessed categorical and continuous CTC-counts for their utility in early prediction of radiographic response, progression-free (PFS) and overall survival (OS) in mCRPC patients treated with docetaxel.CTC-counts were assessed in 122 serial samples, as continuous or categorical (<5 vs. >=5 CTCs) variables, at baseline (q0) and after 1 (q1), 4 (q4) and 10 (q10) cycles of docetaxel (3-weekly, 75 mg/m2) in 33 mCRPC patients. Treatment response (TR) was defined as non-progressive (non-PD) and progressive disease (PD), by morphologic RECIST or clinical criteria at q4 and q10. Binary logistic and Cox proportional hazards regression analyses were used as statistical methods.Categorical CTC-count status predicted PD at q4 already after one cycle (q1) and after 4 cycles (q4) of chemotherapy with an odds ratio (OR) of 14.9 (p=0.02) and 18.0 (p=0.01). Continuous CTC-values predicted PD only at q4 (OR 1.04, p=0.048). Regarding PFS, categorical CTC-counts at q1 were independent prognostic markers with a hazard ratio (HR) of 3.85 (95% CI 1.1-13.8, p=0.04) whereas early continuous CTC-values at q1 failed significance (HR 1.02, 95% CI 0.99-1.05, p=0.14). For OS early categorical and continuous CTC-counts were independent prognostic markers at q1 with a HR of 3.0 (95% CI 1.6-15.7, p=0.007) and 1.02 (95% CI 1.0-1.040, p=0.04).Categorical CTC-count status is an early independent predictor for TR, PFS and OS only 3 weeks following treatment initiation with docetaxel whereas continuous CTC-counts were an inconsistent surrogate marker in mCRPC patients. For clinical practice, categorical CTC-counts may provide complementary information towards individualized treatment strategies with early prediction of treatment efficacy and optimized sequential treatment.
Journal title abbreviation:: BMC Cancer
Year:: 2015
Journal volume:: 15
Pages contribution:: 458
Language:: eng
Fulltext / DOI:: doi:10.1186/s12885-015-1478-4
Pubmed ID:: http://view.ncbi.nlm.nih.gov/pubmed/26051431
TUM Institution:: Institut für Medizinische Statistik und Epidemiologie; Klinik und Poliklinik für Nuklearmedizin; Urologische Klinik und Poliklinik
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