A meta-core outcome set for randomised effectiveness trials and clinical practice for curative surgical oncology:a patient and healthcare consensus statement

Background: The development and use of core outcome sets (COS) have the potential to inform best practice in healthcare treatment options by facilitating data synthesis across studies. In surgical oncology, eight cancer-specific COS exist, and these overlap in content. The development of a meta-COS that includes the core outcomes from existing cancer datasets would be applicable, as a minimum, across all cancer types in surgical oncology for use in effectiveness trials and clinical practice.<br/><br/>Methods: The process included the identification of COS and their discussion with 3 different stakeholder focus groups (surgeons/oncologists, other healthcare professionals, and patients and carers). The outcomes identification was conducted reviewing literature, and registered clinical trials. Stakeholders representing healthcare professionals (surgeons/oncologists and others) were recruited from national societies, regional cancer networks, and local trial centres, whereas patients and carers were recruited using independent representative organisations. The aim was to include at least two individuals from each group for te 10 common cancers requiring surgery. These ten cancer-types investigated were regarded as the commonest based on global incidence on the World Cancer Research Fund data. An agreed-upon list of outcomes was scored in a two-round online Delphi survey (March-May 2025). The results of this online survey were discussed and ratified at an online consensus meeting (June 2025), by Delphi participants who completed both rounds, members of the stakeholder groups, and patients. The 80% threshold defined consensus.<br/><br/>Results: 45 participants completed both survey rounds, and 15 participated at the consensus meeting. Out of 317 outcomes initially identified, 35 were discussed with the stakeholders, 32 were scored in Delphi rounds, and consensus was achieved on eight core outcomes to include in the surgical oncology meta-COS: overall survival, disease-free survival, disease-specific survival, death-related to surgery, delay to further treatment, completeness of tumour removal, overall quality of life, and serious adverse events. <br/><br/>Conclusion: This meta-COS for surgical oncology offers a standard set of outcomes to be used in surgical oncology studies and clinical practice, irrespective of cancer type.<br/>