Laterality describes which side of a paired organ is the origin of the primary cancer. Each side of a paired organ is considered separately and described as lateral when occurring unless a physician determines that it is bilateral.
A paired organ is one in which there are two separate organs of the same kind, one on either side of the body (e.g. kidney, breast, ovary, testis and lung).
Context:
This information is collected for the purpose of differentiating the site of the primary cancer. For example, a woman may present with a primary cancer in the left breast. She may return at a later stage with a new primary cancer in the right breast.
Includes organs that are bilateral as a single primary (e.g. bilateral retinoblastoma (M9510/3, C69.2), (M9511/3, C69.2), (M9512/3, C69.2), (C69.6, C48.0), bilateral Wilms tumours (C64.9, M8960/3)) Note: Bilateral cancers are very rare.
Unknown
It is unknown whether, for a paired organ the origin of the cancer was on the left or right side of the body.
Collection methods:
This information should be obtained from the patient's pathology report, the patient's medical record, or the patient's medical practitioner/nursing staff.
Source and reference attributes
Origin:
World Health Organization
Reference documents:
Percy C, Van Holten V, Muir C (eds). International Classification of Diseases for Oncology, 2nd edition. Geneva: WHO, 1990
