Date of diagnosis must be:

• Greater than or equal to date of birth
• Less than or equal to date of death

Diagnosis of cancer after death:

If the patient is first diagnosed with the cancer in an autopsy report the date of diagnosis is the date of death as stated on the patient's death certificate.

Incidental diagnosis of cancer:

If a patient is admitted for another condition (for example a broken leg or pregnancy), and a cancer is diagnosed incidentally then the date of diagnosis is the date the cancer was diagnostically determined, not the admission date.

Reporting rules:

The date of diagnosis is the date of the pathology report, if any, that first confirmed the diagnosis of cancer. This date may be found attached to a letter of referral or a patient's medical record from another institution or hospital. If this date is unavailable, or if no pathological test was done, then the date may be determined from one of the sources listed in the following sequence:

• Date of the consultation at, or admission to, the hospital, clinic or institution when the cancer was first diagnosed. Note: DO NOT use the admission date of the current admission if the patient had a prior diagnosis of this cancer.
• Date of first diagnosis as stated by a recognised medical practitioner or dentist. Note: This date may be found attached to a letter of referral or a patient's medical record from an institution or hospital.
• Date the patient states they were first diagnosed with cancer. Note: This may be the only date available in a few cases (for example, patient was first diagnosed in a foreign country).

If components of the date are not known, an estimate should be provided with an estimated date flag to indicate that it is estimated. If an estimated date is not possible, a standard date of 15 June 1900 should be used with a flag to indicate the date is not known. Additionally, a date accuracy indicator should be recorded in conjunction with the estimated date.

International Agency for Research on Cancer

World Health Organization

International Association of Cancer Registries