Amy Lord1,2, Gina Brown2, Muti Abulafi2, Adrian Bateman3, Wendy Frankel4, Robert Goldin5, Purva Gopal6, Richard Kirsch7, Maurice B Loughrey8, Bruno Märkl9, Brendan Moran10, Giacomo Puppa11, Shahnawaz Rasheed1, Yoshifumi Shimada12, Petur Snaebjornsson13, Magali Svrcek14, Kay Washington15, Nicholas West16, Newton Wong17, Iris Nagtegaal18. 1. Royal Marsden NHS Trust, London, UK. 2. Croydon University Hospital, London, UK. 3. University Hospital Southampton, Southampton, UK. 4. Ohio State University Wexner Medical Centre, Ohio, USA. 5. Imperial College, London, UK. 6. University of Texas Southwestern Medical Centre, Dallas, USA. 7. Mount Sinai Medical Centre, Toronto, Canada. 8. Royal Victoria Hospital, Belfast Health and Social Care Trust, Belfast, UK. 9. Klinikum Augsburg, Augsburg, Germany. 10. North Hampshire Hospital, Basingstoke, UK. 11. Geneva University Hospital, Geneva, Switzerland. 12. Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan. 13. Netherlands Cancer Institute, Amsterdam, the Netherlands. 14. Hôpital Saint-Antoine, Paris, France. 15. Vanderbilt University Medical Centre, Nashville, USA. 16. University of Leeds, Leeds, UK. 17. University of Bristol, Bristol, UK. 18. Radbound University Medical Centre, Nijmegen, the Netherlands.
Abstract
AIMS: Tumour deposits (TDs) are an important prognostic marker in colorectal cancer. However, the classification, and inclusion in staging, of TDs has changed significantly in each tumour-node-metastasis (TNM) edition since their initial description in TNM-5, and terminology remains controversial. Expert consensus is needed to guide the future direction of precision staging. METHODS AND RESULTS: A modified Delphi consensus process was used. Statements were formulated and sent to participants as an online survey. Participants were asked to rate their agreement with each statement on a five-point Likert scale and also to suggest additional statements for discussion. These responses were circulated together with anonymised comments, and statements were modified prior to carrying out a second online round. Consensus was set at 70%. Overall, 32 statements reached consensus. There were concerns that TDs were currently incorrectly placed in the TNM system and that their prognostic importance was being underestimated. There were concerns regarding interobserver variation and it was felt that a clearer, more reproducible definition of TDs was needed. CONCLUSIONS: Our main recommendations are that the number of TDs should be recorded even if lymph node metastases (LNMs) are also present and that nodules with evidence of origin [extramural venous invasion (EMVI), perineural invasion (PNI), lymphatic invasion (LI)] should still be categorised as TDs and not excluded, as TNM-8 specifies. Whether TDs should continue to be included in the N category at all is controversial, and did not achieve consensus; however, participants agreed that TDs are prognostically worse than LNMs and the N1c category is suboptimal, as it does not reflect this.
AIMS: Tumour deposits (TDs) are an important prognostic marker in colorectal cancer. However, the classification, and inclusion in staging, of TDs has changed significantly in each tumour-node-metastasis (TNM) edition since their initial description in TNM-5, and terminology remains controversial. Expert consensus is needed to guide the future direction of precision staging. METHODS AND RESULTS: A modified Delphi consensus process was used. Statements were formulated and sent to participants as an online survey. Participants were asked to rate their agreement with each statement on a five-point Likert scale and also to suggest additional statements for discussion. These responses were circulated together with anonymised comments, and statements were modified prior to carrying out a second online round. Consensus was set at 70%. Overall, 32 statements reached consensus. There were concerns that TDs were currently incorrectly placed in the TNM system and that their prognostic importance was being underestimated. There were concerns regarding interobserver variation and it was felt that a clearer, more reproducible definition of TDs was needed. CONCLUSIONS: Our main recommendations are that the number of TDs should be recorded even if lymph node metastases (LNMs) are also present and that nodules with evidence of origin [extramural venous invasion (EMVI), perineural invasion (PNI), lymphatic invasion (LI)] should still be categorised as TDs and not excluded, as TNM-8 specifies. Whether TDs should continue to be included in the N category at all is controversial, and did not achieve consensus; however, participants agreed that TDs are prognostically worse than LNMs and the N1c category is suboptimal, as it does not reflect this.