International Classification of Childhood Cancer (ICCC)

The classification of childhood cancer is based on tumor morphology and primary site with an emphasis on morphology rather than the emphasis on primary site for adults. The tables below provide the International Classification for Childhood Cancer (ICCC) definitions based on site and morphology coded according to ICD-O-2 or ICD-O-3.

ICCC, Third Edition (ICCC-3) based on ICD-O-3

Main Classification Table from ICCC-3 based on ICD-O-3
Extended Classification Table from ICCC-3 based on ICD-O-3

These tables contain recodes based on definitions presented in: Steliarova-Foucher E, Stiller C, Lacour B, Kaatsch P. International Classification of Childhood Cancer, Third Edition. Cancer 2005;103:1457-67. © 2005 American Cancer Society.

ICCC-3 Conversion Utility

This conversion utility takes an uncompressed data file with NAACCR version 11 record layout and appends two ICCC-3 recodes (main classification and extended classification) based on site and morphology from the International Classification of Diseases for Oncology (ICD-O-3) to the end of the file. There are three files in the zip file: documentation, an .ini file, and the program.

It is important to note that you cannot use ICD-O-2 data before 2001 and apply the old algorithm, then use the new algorithm for the 2001+ data in ICD-O-3, and analyze them together. When using the ICCC-3 version, all ICD-O-2 morphology (histology, grade, and behavior) codes should first be converted to ICD-O-3. Note that for the extended classification table, cases originally coded in ICD-O-2 and converted to ICD-O-3 will not work for all ICCC extended classifications. For example, under the extended classification, Ia2, ICD-O-2 does not have information about mature B-cell leukemias for acute lymphocytic leukemia, etc. which is needed to subclassify lymphoid leukemia.

In the ICCC, there are certain combinations of histologies, behaviors, and/or sites that are not considered in the schema, and for these we have added a group for unknown ICCC, which includes in situ tumors and some malignant tumors. Therefore, when we produce all sites based on ICCC, we will exclude these cases.

ICCC based on ICD-O-2

International Classification of Childhood Cancer, 1996

This table contains definitions presented in IARC Technical Report No. 29 under the auspices of the International Agency for Research on Cancer (IARC), the International Association of Cancer Registries (IACR), and the International Society of Paediatric Oncology (SIOP). The classification was based on ICD-O-2.

SEER Modification of the ICCC

This table incorporates modifications to the classification of nervous system and bone tumors.