The Get Data Out programme routinely publishes cancer statistics produced by NHS E (previously PHE and NHS D) in a consistent table, called the Get Data Out (GDO) table. This table collects patients into groups with common characteristics, and then publishes information such as incidence, treatment rates, survival and Routes to Diagnosis for these groups.

This document sets out the definitions of the cohort and groups for the Get Data Out tables for the 2023 release of data on haematological malignancies (HM) between 2013 and 2020.

Haematological malignancies cohort

The cohort of haematological malignancies used for Get Data Out is defined by ICD-O-3rev1 morphology and behaviour codes listed in the table in the Appendix. Haematological malignancy transformations registered between 2013 and 2020 are not included in this cohort but are presented in the Haematological malignancy transformations Get Data Out group. For methodology on how to count haematological malignancies see the “Counting Haematological Cases SOP 2.0.pdf” document which can be found in the data releases table on the main technical page.

Haematopoiesis is the formation of blood cellular components within the bone marrow and occurs throughout life. All cellular blood components are derived from haematopoietic stem cells, and matures cells consist of myeloid cells including platelets, erythrocytes, granulocytes, monocytes and dendritic cells, and lymphoid cells such as T- and B-lymphocytes, NK-cells, and plasma cells. HM is a collective term used for neoplasms of the haematopoietic and lymphoid tissues. The World Health Organisation (WHO) classifies HM according to lineage e.g. myeloid, lymphoid, histiocytic, and a normal counterpart cell is thought to account for each neoplasm. As haematopoiesis is a complicated process there are over 150 subtypes of HM. Stem cell or precursor neoplasms such as acute leukaemia are considered separately from mature neoplasms such as lymphomas, myeloma. Leukaemias are cancers which circulate in blood or bone marrow and may be myeloid or lymphoid, and can be acute or chronic. In acute disease, most of the abnormal cells don’t mature and as such don’t carry out normal cellular functions, these diseases tend to progress at a faster rate and are typically much more aggressive. Chronic disease on the other hand, occurs when there is a mix of normal cells alongside a population of immature cells and as such, these diseases tend to be slower growing. Lymphomas are cancer of mature lymphocytes (B-, T-, NKT- or NK- cells). Further subclassification of disease are made using clinico-pathological entities such as clinical features, morphology, immunophenotype and genetic abnormalities to define disease.

In total, 157 distinct morphological entities of HM have been grouped to form 42 overarching subtypes, with further subclassification according to the cell lineage. HM have been categorised in to 16 myeloid groupings and 23 lymphoid groupings for the purpose of Get Data Out and to avoid disclosing small numbers. Analysis includes patients of all ages, diagnosed in England between 2013 and 2020 and excludes patients diagnosed with monoclonal gammopathy of undetermined significance (9765/1). Further details on each specific HM and how they have been grouped are given in the document “Haematological Malignancy Descriptions.pdf” which can be found in the data releases table on the main technical page.

An overview of the groupings for the HM cohort is as follows.

Year

The cohort is first split by the year of diagnosis.

The first four partitions are to split haematological malignancies into distinct Tumour Types by ICD-O-3rev1 morphology and behaviour codes. The definitions for Tumour Types 1-4 can be found in the table in the Appendix for SPLIT_1, SPLIT_2, SPLIT_3 and SPLIT_4 accordingly. In addition, for Tumour Type 3, tumour ICD-O-3 site is used to define if Mature T-cell and NK-cell neoplasms are a Cutaneous T-cell lymphoma or other.

Tumour Type 1

Haematological malignancies were classified based on morphology and behaviour as coded in ICD-O-3 into:

Tumour Type 2

Lymphoid is further classified into:

Myeloid is further classified into:

Other haematological malignancies are further classified into:

These classifications are made on ICD-O-3 morphology and behaviour.

Tumour Type 3

Where appropriate for the haematological malignancy subtypes defined above, groups are classified further by ICD-O-3 morphology and behaviour as defined below.

Acute lymphoblastic leukaemia (ALL) is further classified into:

Hodgkin lymphoma is further classified into:

Mature B-cell neoplasms are further classified into:

Plasma cell neoplasms are further classified into:

Myelodysplastic syndromes (MDS) are further classified into:

Myeloproliferative neoplasms (MPN) are further classified into:

Mature T-cell and NK-cell neoplasms are further classified into the following two groups by site ICD-O-3. Mature T-cell and NK-cell neoplasms with a skin tumour site are classified as cutaneous (please see the GDO Skin_Grouping document for the skin site definition).

Tumour Type 4

Follicular lymphoma is further classified by ICD-O-3 morphology and behaviour into:

Age

The next split for any Tumour Type group is by age of the patient at diagnosis. Only groups which contain a large enough patient count were split by age.

B-cell acute lymphoblastic leukaemia (B-cell ALL) and acute lymphoblastic leukaemia (ALL) NOS groups were partitioned by age into:

Classic Hodgkin lymphoma was partitioned by age into:

Nodular lymphocyte predominant Hodgkin lymphoma was partitioned by age into:

Where numbers allow, mature B-cell neoplasm subgroups, mature T-cell and NK-cell neoplasm subgroups, plasma cell neoplasm subgroups, lymphoproliferative disorders and non-specific malignancies, chronic myelomonocytic leukaemia (CMML) malignancies, myelodysplastic syndromes (MDS) subgroups, and myeloproliferative neoplasms (MPN) subgroups were partitioned by age into:

Acute myeloid leukaemia (AML) was partitioned by age into:

Stage

Where staging is appropriate, and numbers allow, lymphoid subgroups are partitioned by stage at diagnosis. Three main staging systems are used for haematological malignancies; lymphomas are staged in Ann Arbor (stages 1-4), myelomas are staged in the International Staging System (ISS, stages 1-3), and B-cell chronic lymphocytic leukaemias (CLLs) are staged in Binet (stages A-C).

The 20-59 and 60+ age groups for classic Hodgkin lymphoma, 0-69 and 70+ age groups for diffuse large B-cell lymphoma (DLBCL) and other high grade, and the 0-69 and 70+ age groups for follicular grade 1 and 2 are partitioned into Ann Arbor stages as:

The 0-69 and 70+ age groups of follicular grade 3, other follicular, and marginal zone lymphoma (nodal, extranodal, MALT) are partitioned into Ann Arbor stages as:

The 0-69 and 70+ age groups of chronic lymphocytic leukaemia (CLL) (small lymphocytic lymphoma (SLL) tumours are not partitioned by stage) are partitioned into Binet stages as:

The 0-69 and 70+ age groups of myeloma are partitioned into ISS stages as:

The registration of 2019 tumours were being completed during the COVID-19 pandemic. This led to reduced access to the usual data sources, and despite the registry’s best efforts a noticeable decrease in data quality in some fields. This is most commonly seen in an increase in ‘stage unknown’ tumours, and a corresponding decrease in other stage groups. This should be noted when undertaking time-series analysis on the data.

The majority of all haematological malignancies are staged in the Ann Arbor, ISS, or Binet systems. A small percentage of cancers were staged in other systems, as reported in the known limitations page. The following table shows the percentage of cases staged in each of Ann Arbor, ISS, and Binet over time.

Deprivation

Some subgroups within lymphoid and myeloid are partitioned by Index of Multiple Deprivation (IMD) quintiles. This is the first cancer site within GDO to be partitioned by deprivation. Deprivation is measured on scale a of 1 to 5, with 1 being most deprived and 5 being least deprived, and is based on the patients postcode of residence at the time of diagnosis. Where applicable and where numbers allow, groups are split by age, followed by stage, followed by deprivation, however in some cases deprivation follows immediately from age.

The following morphology, age, and stage groups:

are partitioned by deprivation into:

Gender

Where numbers allow, or where the numbers in a group are not large enough to split by stage and/or deprivation, groups are then split by gender into male and female.

Appendix

ICD-O-3 morphology and behaviour codes included in this cohort and their subgroups