IACR Official Website - International Association of Cancer Registries

ICD-O

INTERNATIONAL CLASSIFICATION OF DISEASES FOR ONCOLOGY (ICD-O)

International Classification of Diseases, 4^th Edition (ICD-O-4)

Following the completion of the 5^th Edition of WHO Classification of Tumours (Blue Books), the ICD-O-3.2 classification (morphology table available in the links below) has been updated with new morphology codes and terms. The ICD-O-4 classification has a new morphology structure with 5-digit morphology codes, in which the 5^th digit can be “0” or have other values (including alphanumeric), if more specific codes are needed. This new structure enables the assigning of specific codes to each separate cancer entity that were previously included as related terms. ICD-O-4 also contains an updated topography list. The new edition, ICD-O-4, will become available in 2025.

Alongside the ICD-O-4 morphology and topography list, we are providing listings of additions, changes, and revisions between ICD-O-3.2 and ICD-O-4 as reference material for cancer registries in the following tables:

1. New morphology codes:
   1. First 4 digits present in ICD-O-3.2 and 5^th digit different from “0”
   2. First 4 digits present in ICD-O-4, but not in ICD-O-3.2
2. Changes between ICD-O-3.2 and ICD-O-4:
   1. Morphology at the 4-digit level
   2. Topography

These documents are available here: https://tumourclassification.iarc.who.int/icdo4/

Please provide any comments or queries using the feedback function (contact form).The site is open for feedback until the 1^st of November 2024.

After the consultation period, ICD-O-4 will be reviewed, and the book generated as an online pdf.

ICDO- THIRD EDITION, SECOND REVISION MORPHOLOGY

• A summary of the main changes
• Terms that are changing behaviour
• New codes and their terms
• Deleted codes and their terms
• Updated table: "Groups of malignant neoplasms considered to be histologically different for the purpose of defining multiple tumours" to be used with ICD-O-3.2 (The rest of the multiple primary rules remain unchanged.)

A LISTING OF ALL ADDITIONS, CHANGES AND REVISIONS TO THE ICD-O-3, IST REVISION (ICDO-O-3.1) FOR ICD-O-3.2

• Japanese Translation

Third edition Edited by A. Fritz, C. Percy, A. Jack,  K. Shanmugaratnam, L. Sobin,D.M. Parkin  and S. Whelan

Please consult the previous versions online and the new links for ICD-O (2nd revision) as follows:

ICD-O 3

ICD-O 3 (1st rev)

As it is no longer possible to maintain and update the previous http://codes.iarc.fr website, it was decommissioned on 31 July 2019. IARC is updating its web domain and it is not possible to maintain this website on the new platform. We apologize for any inconvenience as a result of the decommissioning.

¹ Ian Cree, Jacques Ferlay, Robert Jakob, Brian Rous, Reiko Watanabe, Valerie White, Ariana Znaor

² Atul Budukh, Jacques Ferlay, Keri Green, Tomohiro Matsuda, Brian Rous, Ariana Znaor