Colorectal cancer staging using TNM 7: is it time to use this new staging system?
- Department of Cellular Pathology, University Hospital Southampton NHS Foundation Trust, Southampton, UK
- Correspondence to Dr A C Bateman, Department of Cellular Pathology, Southampton General Hospital, MP002, Level E, South Block, Tremona Road, Southampton SO16 6YD, UK;
Contributors ACB developed the original idea for the audit, reported many of the cases, helped to analyse the data, wrote the first draft of the manuscript. VJD gathered and tabulated the data, performed much of the data analysis, commented on the first draft of the paper and discussed/finalised the script with ACB.
- Accepted 15 November 2011
- Published Online First 7 January 2012
The authors audited pathological colorectal cancer staging according to tumour node metastasis (TNM) 7 and using TNM 5 as a gold standard. 144 consecutive colorectal cancer resection specimens were staged prospectively using both TNM 5 and TNM 7 criteria during routine reporting by specialist gastrointestinal pathologists within a single institution. The pN stage remained the same under both systems apart from the required subclassification of pN1 and pN2 under TNM 7. The TNM 7 pN1c category was used in only 3% of cases. All cases staged as pT4 underwent reversal of pT4 subclassification using TNM 7 compared with TNM 5. A previous study revealed stage migration from pN1 to pN2 in 32.6% of cases under TNM 7 compared with TNM 5. The difference in frequency of pN stage migration between this study and our audit suggests that the application of TNM 7 to the assessment of discontinuous/satellite tumour foci is subject to significant inter-observer variability.
- Colorectal cancer
- gut pathology
- gastric pathology
- gastric cancer
- autopsy pathology
- liver disease
Competing interests ACB is a member of the UK TNM committee.
Ethics approval This is an audit and hence ethics approval was not obtained.
Provenance and peer review Not commissioned; externally peer reviewed.