Standardizing the Definition of Each Colon Cancer Segment: Delphi Consensus on Clinical Decision-Making for Oncologic...

Area of Science:

• Oncology
• Surgical Gastroenterology
• Medical Informatics

Background:

• Current data registries lack a standardized classification for distinct colon cancer locations.
• This deficiency hinders accurate data analysis and comparative studies in colon cancer research.

Purpose of the Study:

• To achieve international consensus on defining primary colon cancer segment locations.
• To develop standardized definitions for each segment of the colon affected by cancer.

Main Methods:

• A three-round, online Delphi survey was conducted with international experts from December 2022 to June 2023.
• Experts ranked 17 statements on a scale of 1-9, with consensus reached for scores of 7-9 and moderate/high consensus (above 4 for >70%) in the final round.
• The study focused on precise localization of cancer segments, not surgical treatment specifics.

Main Results:

• A total of 331 experts participated, with high completion rates across all three rounds (91%-98%).
• Strong support was found for a "10-cm rule" and anatomical landmarks for defining colon cancer sites.
• Consensus was reached to abolish the term "rectosigmoid cancer" by European and US experts, contrasting with Asian experts; 64% consensus was achieved for describing overlapping cancer segments.

Conclusions:

• The Delphi survey successfully established a high level of international consensus on colon cancer segment definitions.
• A standardized approach, including the "10-cm rule," was supported for improved classification.
• Persistent ambiguity exists regarding the precise definition and classification of overlapping colon cancer lesions.