Here are some concepts that, due to their importance and characteristics, require a precise definition or specification of the type of classification used.
The necessary conditions to register a case are:
- To reside at the time of diagnosis in the geographic area where the Registry is located, which means to be included in the population census and
- Being diagnosed for the first time with invasive or in situ cancer, after the date on which the Registry begins its activity. An explicit definition will be made of the cases that can be registered (benign, malignant or uncertain) and of those that will be included in the annual incidence statistics (in which cancers in situ are excluded).
The unit of registration is the cancer and not the patient, so that a patient with 3 primary cancers, for the purposes of registration and incidence, is registered as 3 different cases. For the classification and coding of multiple primary tumors, the standards proposed by the IARC/IACR. are followed.
The essential data to register a case are: personal identification data, sex, age of the patient on the date of diagnosis, the date of incidence, the location of the tumour, and its morphology. This information, together with the number of inhabitants and the distribution by age groups and sex of the population, is essential to determine the standardized and age-specific incidence rates of the different types of cancer.
It will be the basic reference for incidence or survival studies. Between the dates of choice (clinical diagnosis, hospital admission,...), the anatomopathological diagnosis will be taken as a priority , following the recommendations of the ENCR.
Organ in which the cancer originates. It is coded following the International Classification of Diseases for Oncology, 3rd edition (ICD-O-3).
Histological / cytological type of cancer. It is also coded following the ICD-O-3.
If there are several diagnostic tests, the one considered most reliable for the diagnosis is coded with priority (histology, cytology, tumor markers, imaging methods ...).
Whenever possible, the TNM classification system and its conversion into stages are used. For certain types of tumors, such as lymphomas, the classifications commonly used in the clinic (Ann Arbor) will be used. In the absence of data on the stage, the clinical extension of the tumor (localized, regional or disseminated) can be coded, provided that there is sufficient information to do so.
The definition used will be made explicit, either based on the planned therapy and / or the period of time that has elapsed since its initiation, generally the first 6 months.