Validation of surrogate end points for overall survival in advanced colorectal cancer: further need for clarification: Letter to the editor on: Ciani et al., 2015, Meta-analyses of randomized controlled trials show suboptimal validity of surrogate outcomes for overall survival in advanced colorectal cancer. 2015, J Clin Epidemiol 68:833-842.
Institute for Quality and Efficiency in Health Care, Im Mediapark 8, Cologne, Germany. Electronic address: christoph.schuermann@iqwig.de.
Christoph
C
Schürmann
Institute for Quality and Efficiency in Health Care, Im Mediapark 8, Cologne, Germany.
Beate
B
Wieseler
D014408:Biomarkers, Tumor / Q000032:analysis*; D015179:Colorectal Neoplasms / Q000401:mortality* / Q000628:therapy*; D006801:Humans
D014408:Biomarkers, Tumor