Clinical Practice Guidelines - National Health and Medical Research ...

14.4 Translation between staging systems
A matrix for translating between staging systems was developed by a working party on staging, which
reported in 1990. 12 The international comprehensive anatomical terminology (ICAT) for Colorectal
Cancer and matrix for staging conversion is shown in Table 14.4. 13
14.5 Additional information on pathology
Apart from tumour stage, the importance of including information on a range of other variables in the
histopathology report is recognised, (refer to Table 14.5). These variables include the components of
stage and some other factors that have been shown to have a bearing on prognosis. The independent
prognostic effects of many of these variables have been assessed within the ACPS system and have
been demonstrated to be stage dependent. 12,14,15
The pTNM staging system uses an alphanumeric shorthand method of defining the extent of tumour
spread. This terminology is detailed but it does not permit the separate designation of cases where
tumour spread specifically involves a free serosal surface. This aspect of tumour spread has been
shown to be an important prognostic variable. 14–16 As has been mentioned, the code for local residual
tumour (the R classification) is optional.
Table 14.5 Reporting on Colorectal Cancer specimens
The following list of variables should be addressed when reporting on Colorectal Cancer specimens:
1. Extent of direct spread of tumour (submucosa, muscularis propria, subserosa, free serosal
surface, adjacent organ/structure, surgical lines of resection). Distance of tumour from
longitudinal margins, radial margins and anal verge (in those having an abdominoperineal
resection).
2. Lymph node involvement (number of involved nodes, presence or absence of
extracapsular extension, apical node involved or not). The number of nodes examined
should be recorded as a guide to the adequacy of the lymph node harvest.
3. Lymphovascular invasion present or absent.
4. Perineural invasion present or absent.
5. Tumour histology
• tumour type (adenocarcinoma, mucinous adenocarcinoma*, signet ring cell*, large cell
undifferentiated*)
• grade of differentiation (well, moderately or poorly differentiated)
• margin (expanding or infiltrating)
• peritumoural and tumour infiltrating lymphocytes*
• presence or absence of necrosis in those patients having preoperative adjuvant therapy
6. Histology of any biopsy material.
* Histological variables are useful diagnostic markers for hereditary nonpolyposis colon cancer
(HNPCC) and sporadic cancers showing microsatellite instability (MSI). 17,18
164 The prevention, early detection and management of colorectal cancer