Standard cancer group definitions

The purpose of this page is to define our standard NDRS cancer groups in terms of International Classification of Diseases (ICD) and International Classification of Diseases for Oncology (ICD-O) coding. Some cancer groups are also defined by patient characteristics such as gender, and some cancer group definitions change over time and so are defined also by diagnosis year.

NDRS cancer publications aim to publish on ‘NDRS main’ cancer groups and, where appropriate, ‘NDRS detailed’ cancer groups. As an example, a publication might report on ‘Lung cancer’ as the NDRS main group and ‘Small-cell-lung-cancer (SCLC)’ and ‘Non-small-cell-lung-cancer (NSCLC)’ as NDRS detailed groups. These groups are usually defined in ICD-10 and ICD-O3, and the downloadable items from this page aim to detail these definitions.

For some publications, defining groups in ICD-O3 may not be appropriate. An example of this is cancer prevalence which requires a standard cancer group definition back to 1995, when ICD-O3 was not in use. We have therefore also detailed ‘Other main’ and ‘Other detailed’ cancer groups in the first downloadable item (the HTML page) which are defined solely in ICD-10.

Standard definitions of cancer groupings for routine publications will always require some decisions on ‘grey area’ cancers. The questions relating to ‘grey area’ cancers are broadly

1. When do we include cancers that are in sites very near to the main site and that grow similar cancers? For example, should cancers of the trachea be included with lung? Should cancers of the ureter be included with bladder?
2. When do we include tumours that are registrable but not invasive? For example, should borderline tumours of ovary be included with ‘ovarian cancer’? Should carcinomas in situ (CIS) of bladder be included with ‘bladder cancer’?

There are also pragmatic decisions to be made based on how common a cancer is. For example, we can produce routine statistics by a variety of characteristics such as deprivation and stage on a cancer where 10,000 cases are registered a year more easily than we can on a cancer where there are only 100. We have worked with clinicians, charities, and other subject matter experts to try and make clear and documented definitions on these edge cases. We do try to produce internationally comparable statistics, but as ICD-10 was released in 1994 and our understanding of cancer has changed in the last 30 years, our main groups may not align with other definitions produced by other sources. We recommend you always carefully check the definition of a group when comparing between publications.

Some NDRS publications may not yet be using these cancer group definitions given on this page. Where a publication is using either the NDRS or Other cancer group definitions, their publication/dashboard should clearly state this and link to this page. Please read the methodology for a specific publication to check the definitions of cancer groups they are using.

Some NDRS publications report on bucket groups of 'All malignant cancer', to give headline figures about cancer diagnoses and statistics in England, or to allow for the statistics about a single cancer group to be put into perspective of the total number of malignant cancers diagnosed in England. An 'All malignant cancer' group is difficult to define and different definitions may be relevant in different situations. The document 'NDRS all cancer definitions' which is downloadable from the 'Data downloads' section of this page outlines the different ways in which NDRS defines ‘All malignant cancer’ and the reasoning behind each definition.

Acknowledgement

This work uses data that has been provided by patients and collected by the NHS as part of their care and support. The data are collated, maintained and quality assured by the National Disease Registration Service, which is part of NHS England.

This page, along with the downloadable items, will be updated annually. Each year, some of our cancer group definitions (or even the names given to some of our cancer groups) may change slightly from the previous year. For example, where subgroups are defined by a list of morphology codes - if a morphology code is registered for the first time in a given year which has not been seen by the registry before, it will need to be reviewed and put into the appropriate subgroup. This will mean that the lookup for this subgroup will have an additional morphology code in the new years definition. We do not expect major definitional changes to any of our groups between years.

From the 'Data downloads' below you should select the year of cancer registrations which is relevant for the publication you are interested in. This should be stated within the publication itself, but in general if a publication reports on cancer diagnoses up to 2022 you should use the 'Finalised 2022 registrations definitions' and if a publication reports on cancer diagnoses up to 2023 you should use the 'Finalised 2023 registrations definitions', and so on. Publications which report on cancer diagnoses with a maximum diagnosis year of 2021 or before may not yet be using the NDRS standard cancer group definitions. Please refer to the methodology section of such publications for their cancer group definitions.

This information is produced by the National Disease Registration Service (NDRS). Please send any feedback or queries to [email protected] 

Please do not include sensitive or patient identifiable information.