Abstract
The Patient-Reported Outcomes version of the Common Terminology Criteria for Adverse Events (PRO-CTCAE) was developed by the US National Cancer Institute to allow patients to directly report their side effects, enhancing the accuracy and patient-centeredness of cancer clinical trial adverse event reporting. Clinician-based reporting often misses the full range of patient symptoms, resulting in underreporting of side effects. The selection of adverse events for patient reporting must be defined in advance and consistently applied across all study arms. Investigators can use core symptom sets, including diarrhea, fatigue, and nausea, alongside tailored items specific to the treatments being studied. PRO-CTCAE has demonstrated similar scores across electronic, paper-based, and automated telephone administration methods. PRO-CTCAE administration typically occurs before start of treatment and regularly throughout treatment, with the administration frequency tailored to the expected trajectory of side effects. Ensuring high survey completion rates is essential for PRO-CTCAE success. Standard reporting can include tabular reporting of the proportion of patients with any (score ≥1) and high (score ≥3) levels of symptoms at the individual item level. A baseline-adjustment approach should be applied to account for symptoms before start of treatment to isolate treatment-emergent adverse events. The distribution of PRO-CTCAE scores at each time point can be visualized using stacked bar charts. PRO-CTCAE integration into cancer clinical trials is crucial for capturing a comprehensive range of treatment-related symptomatic adverse events and improving the evaluation of therapy tolerability. Ongoing research continues to refine its implementation, supported by regulatory guidance.