Wiggers, Theo

BACKGROUND: Data registries lack a definitive classification system that distinguishes different locations of colon cancer from one another. OBJECTIVE: To establish an international consensus on the definition of primary colon cancer segment locations. DESIGN: Between December 2022 and June 2023, Delphi survey study was conducted to seek opinions from relevant international experts and eventually develop a consensus definition of each colon cancer segment. SETTING: Three-round online-based Delphi survey study. INTERVENTIONS: Online survey included 17 questions. In the first two rounds, participating experts were asked to rank each statement on a scale of 1–9 (9 is the most relevant). Consensus statements and definitions were revised according to results, obtaining a consensus score of 7–9. During the third round and online meeting, definitions and statements reached a moderate or high consensus(above 4 in more than 70% of participants) were included. MAIN OUTCOME AND MEASURE: Primary goal of our project was focused on precisely localizing the specific segment affected by primary colon cancer, rather than to identify surgical treatment or type of resection needed for particular segment. RESULTS: The first round included 331 experts, 301 (91%) completed the second round, and 295 (98%) completed the final round. Experts strongly supported the use of a “10 cm rule” to describe colon cancer sites at the flexures and anatomical landmarks for other segments. Regarding the definition of rectosigmoid cancer, experts from America and Europe reached a high consensus that the term rectosigmoid as a colon cancer location must be abolished in contrast to experts from Asia. Description of cancers overlapping segments achieved a consensus of 64%. LIMITATIONS: Subjective decisions are based on individual expert clinical experience. CONCLUSIONS: This Delphi survey, the first internationally conducted consensus study, achieved a remarkable level of consensus among a panel of global experts. Ambiguity still exists regarding overlapping lesions. See Video Abstract .

Consensus abstract Background The management of primary rectal cancer beyond total mesorectal excision planes (PRC-bTME) and recurrent rectal cancer (RRC) is challenging. There is global variation in standards and no guidelines exist. To achieve cure most patients require extended, multivisceral, exenterative surgery, beyond conventional total mesorectal excision planes. The aim of the Beyond TME Group was to achieve consensus on the definitions and principles of management, and to identify areas of research priority. Methods Delphi methodology was used to achieve consensus. The Group consisted of invited experts from surgery, radiology, oncology and pathology. The process included two international dedicated discussion conferences, formal feedback, three rounds of editing and two rounds of anonymized web-based voting. Consensus was achieved with more than 80 per cent agreement; less than 80 per cent agreement indicated low consensus. During conferences held in September 2011 and March 2012, open discussion took place on areas in which there is a low level of consensus. Results The final consensus document included 51 voted statements, making recommendations on ten key areas of PRC-bTME and RRC. Consensus agreement was achieved on the recommendations of 49 statements, with 34 achieving consensus in over 95 per cent. The lowest level of consensus obtained was 76 per cent. There was clear identification of the need for referral to a specialist multidisciplinary team for diagnosis, assessment and further management. Conclusion The consensus process has provided guidance for the management of patients with PRC-bTME or RRC, taking into account global variations in surgical techniques and technology. It has further identified areas of research priority.

Consensus abstract Background The management of primary rectal cancer beyond total mesorectal excision planes (PRC-bTME) and recurrent rectal cancer (RRC) is challenging. There is global variation in standards and no guidelines exist. To achieve cure most patients require extended, multivisceral, exenterative surgery, beyond conventional total mesorectal excision planes. The aim of the Beyond TME Group was to achieve consensus on the definitions and principles of management, and to identify areas of research priority. Methods Delphi methodology was used to achieve consensus. The Group consisted of invited experts from surgery, radiology, oncology and pathology. The process included two international dedicated discussion conferences, formal feedback, three rounds of editing and two rounds of anonymized web-based voting. Consensus was achieved with more than 80 per cent agreement; less than 80 per cent agreement indicated low consensus. During conferences held in September 2011 and March 2012, open discussion took place on areas in which there is a low level of consensus. Results The final consensus document included 51 voted statements, making recommendations on ten key areas of PRC-bTME and RRC. Consensus agreement was achieved on the recommendations of 49 statements, with 34 achieving consensus in over 95 per cent. The lowest level of consensus obtained was 76 per cent. There was clear identification of the need for referral to a specialist multidisciplinary team for diagnosis, assessment and further management. Conclusion The consensus process has provided guidance for the management of patients with PRC-bTME or RRC, taking into account global variations in surgical techniques and technology. It has further identified areas of research priority.