Person with cancer—primary site of cancer, topography code (ICD-O-3) ANN.N

Guide for use:

Record the primary site of cancer, if known, for patients who have been diagnosed with cancer. When the primary site is unknown, record C80.9.

The primary site of the tumour is the site of origin, as opposed to the secondary or metastatic site.

Record all four alphanumeric characters of the topography code. The number after the decimal point represents the subsite or subcategory.

Refer to the coding guidelines for topography in ICD-O-3, pp 23-26.

Refer to the coding guidelines for multiple tumours in ICD-O-3, pp 35-37.

If the patient is diagnosed with more than one primary tumour, record the site of each primary separately.

If the primary site differs on multiple pathology or other notification reports for the same tumour, use the most specific value. For example, one report may state the breast (C50.9) is the site of the primary while another report records the lower-inner quadrant of the breast (C50.3) as the primary site; record C50.3 here as the primary site.

Origin:
World Health Organization

Comments:
The information is collected so that tumours can be classified into clinically relevant groups based on their primary site and histological type. This provides a basis for staging and the determination of treatment options. The primary site of the cancer also affects the course of the disease and prognosis.