Purpose There is increasing interest to use patient-reported outcome (PRO) measures to evaluate symptomatic adverse events (AEs) in cancer treatment trials. However, there are currently no standard recommended approaches for integrating patient-reported AE measures into trials. Methods Approaches are identified from previous trials for selecting AEs for solicited patient reporting, administering patient-reported AE measures, and analyzing and reporting results. Findings Approaches for integrating patient-reported AE measures into cancer trials generally combine current standard methods for clinician-reported AEs and established best practices for using PRO measures. Specific AEs can be selected for a PRO questionnaire based on common and expected reactions in a given trial context, derived from literature review and qualitative/mixed-methods evaluations and should be the same set administered across all arms of a trial. A mechanism for collecting unsolicited patient-reported AEs will also ideally be included. Patients will preferably report at baseline and at the end of active treatment as well as on a frequent standardized schedule during active treatment, such as weekly from home, with a recall period corresponding to the frequency of reporting (eg, past 7 days). Less frequent reporting may be considered after an initial intensive monitoring period for trials of prolonged treatments and during long-term follow-up. Electronic PRO data collection is preferred. Backup data collection for missed PRO reports is advisable to boost response rates. Analysis can use a combination of approaches to AE and PRO data. If a high proportion of patients is experiencing baseline symptoms, systematic subtraction of these from on-study AEs should be considered to improve reporting of symptoms related to treatment. More granular longitudinal analyses of individual symptoms can also be useful. Implications Methods are evolving for integrating patient-reported symptomatic AEs into cancer trials. These methods are expected to further evolve as more data from trials become available