Finalised 2013-2024 registrations definitions

This page lists the 2013-2024 NDRS standard cancer groups where there has a been a change in definition, compared to 2013-2023

Bowel

The NDRS main bowel group (also referred to as colorectal) was previously coded as ICD-10 C18-C20. After discussions with the Get Data Out (DGO) bowel cancer working group, the decision was taken to remove appendix (ICD10 C18.1) from the group. Many tumours of the appendix are appendiceal neuroendocrine tumours (also known as carcinoids of the appendix) which are slow growing tumours often discovered as incidental findings following an appendectomy. These tumours are published in the separate group 'Appendix' as they have very different morphological and survival profiles to the rest of the bowel.

The group is now called 'Bowel (excluding appendix)'. It is broadly defined as ICD-10 C18-C20 (excluding C18.1) but also includes the following small changes:

• all gastrointestinal stromal sarcoma (GIST) registered to the bowel (ICD-0-3.1 C18-C20 excluding C18.1), are included in the group, regardless of whether they were coded as malignant cancer when they were registered. This is to correct historical inconsistencies and produce a reliable timeseries, as due to changing understanding of these cancers, in some years they were registered as malignant and some years they were registered as non-malignant. This change to the group definition only relates to tumours previously coded with ICD-10 code D01.0-D01.2 or D37.4-D37.5. The codes for identifying GIST can be found in the HTML lookup under Bowel (excluding appendix)

• all neuroendocrine neoplasms (NEN) registered to the bowel (ICD-O-3.1 site C18-C20 excluding C18.1), are included in the group, regardless of whether they were coded as malignant cancer when they were registered. This is to correct historical inconsistencies and produce a reliable timeseries, as due to changing understanding of these cancers, in some years they were registered as malignant and some years they were registered as non-malignant. This change to the group definition only relates to tumours with ICD-10 code D01.0-D01.2 or D37.4-D37.5. The codes for identifying NEN can be found in the HTML lookup under Bowel (excluding appendix)

• all squamous cell carcinomas of the rectum (ICD-10 C20) are excluded from this group and included with Anus. This is because our expert working group felt these are much more likely to be large / overlapping anal tumours which have spread to the rectum than true squamous cell carcinomas of the rectum, due to the histology of cells in the rectum and anus. A full list of squamous cell carcinoma morphology codes can be found in the HTML lookup under Anus

• most adenocarcinomas of the anus (ICD-10 C21) are excluded from Anus and included in Bowel (excluding appendix). This is because our expert working group felt these are much more likely to be large / overlapping rectal tumours which have spread to the anus than true adenocarcinomas of the anus, due to the histology of cells in the rectum and anus. A full list of adenocarcinoma morphology codes can be found in the HTML lookup under Bowel (excluding appendix). Tumours that are specifically coded to adenocarcinoma of anal glands (ICD-O-3.1 8215), adenosquamous carcinoma (ICD-O-3.1 8560) and extramammary Paget disease (ICD-O-3.1 8542) are not reassigned

The NDRS detailed subgroups have changed from ‘Colon’, ‘Rectosigmoid junction’, and ‘Rectum’ to ‘Left colon adenocarcinoma’, ‘Right colon adenocarcinoma’, ‘Rectosigmoid junction adenocarcinoma’, ‘Rectum adenocarcinoma’, and ‘Other bowel cancer’. With the exception of ‘Other bowel cancer’, the new subgroups are restricted to adenocarcinomas of bowel, with unusual tumours of other morphologies (whose staging and survival can be very different) included in the ‘Other bowel cancer’ subgroup alongside all colon tumours with unknown or unspecified site.

Appendix

Appendix (ICD-10 C18.1) has been removed from the bowel group and is now its own NDRS main group. The group includes all GIST and NEN registered to the appendix (ICD-0-3.1 C18.1) regardless of whether they were coded as malignant cancer when they were registered. This change to the group definition only relates to tumours with ICD-10 code D01.1 or D37.3. Please see the list of changes under Bowel for the justification.

Anus

The NDRS main Anus group, previously defined as ICD-10 C21, is now defined as ICD10-10 C21 and all squamous cell carcinomas of the rectum (ICD-10 C20). Most adenocarcinomas of the anus are excluded. The group includes all GIST and NEN registered to the anus (ICD-O-3.1 C21) regardless of whether they were coded as malignant cancer when they were registered. This change to the group definition only relates to tumours with ICD-10 code D01.3 or D37.7. Please see the list of changes under Bowel for the justification.

Small intestine

The NDRS main small intestine group, previously defined as ICD-10 C17 alone, now also includes all GIST and NEN registered to the small intestine (ICD-0-3.1 C17) regardless of whether they were coded as malignant cancer when they were registered. This change to the group definition only relates to tumours with ICD-10 code D01.4 or D37.2. Please see the list of changes under Bowel for the justification.

Bladder

Three bladder NDRS detailed groups (T1 non-muscle-invasive urothelial, muscle-invasive urothelial, and Unknown stage urothelial) have been combined to create malignant bladder. This group was created to easily allow malignant cases to be distinguished from cases with non-malignant behaviour. The other groups (‘Ta/Tis non-muscle-invasive urothelial and other morphology’ and ‘Other morphology or uncertain/unknown behaviour’) remain the same.

Other malignant

Bone (ICD-10 C40-C41), Soft tissue (ICD-10 C47, C48 with specific ICD-0-2 morphology codes, C49), and Kaposi sarcoma (ICD-10 C46) are no longer separate NDRS main groups. They are now included in the NDRS main 'Other malignant' group, with NDRS detailed as Bone, Soft tissue or Kaposi sarcoma. A separate sarcoma group, defined only in ICD-0-3, is available.