Clinician-reported symptomatic adverse events in cancer trials: are they concordant with patient-reported outcomes?

We investigate the concordance, in terms of favoring the same treatment arm, between clinician-reported symptomatic adverse events (AEs) and information obtained via patient-reported outcomes (PRO) measures in cancer randomized controlled trials (RCTs). We conducted a systematic literature search to identify all RCTs conducted in breast, colorectal, lung and prostate cancer, published between 2004 and 2017. We identified 207 RCTs. In the majority of RCTs (n=133, 64.2%) a discordance between PROs and AEs was found. In 104 studies (50.2%), PRO data favored the experimental arm when AEs did not, while the opposite situation was found in 29 trials (14.0%). Frequently, information obtained via PRO measures and clinician-reported AEs do not favor the same treatment arm in RCT settings.