International Classification of Diseases for Oncology

International Classification of Diseases for Oncology (ICD-O) is a domain-specific extension of the International Classification of Diseases (ICD) for tumor diseases. This classification is widely used by cancer registries worldwide for the coding of histology, topography and the behavior of neoplasms. The ICD-O was first published by the World Health Organization (WHO) in 1976 and is currently in its third revision (ICD-O-3).

History

The ICD-O was developed in response to the need for a standardized system for classifying oncological diseases. The first edition was published in 1976, followed by the second edition in 1990. The third and current edition, ICD-O-3, was published in 2000 and has been updated periodically to reflect advances in our understanding of cancer.

Structure

The ICD-O uses a dual coding system to classify neoplasms by both their site (topography) and histology (morphology). The topography code uses the same structure as the ICD, with the addition of a letter to denote the side of the body. The morphology code is a five-digit number, with the first four digits representing the histological type of the tumor and the fifth digit representing its behavior (benign, malignant, in situ, etc.).

Usage

The ICD-O is used by cancer registries worldwide for the coding of histology, topography and the behavior of neoplasms. It is also used in clinical settings for the diagnosis and treatment of cancer, as well as in research to study the epidemiology and etiology of cancer.

See also

• International Classification of Diseases
• World Health Organization
• Cancer registry
• Oncology