The classification of tumour types and subtypes with somatic mutations in the published literature is extremely variable. Classification systems and terminologies differ between reports and indeed may have changed over time. Rather than simply entering a neoplasm using the term employed in the published report, COSMIC uses its own internal classification system to provide tissue and histology consistency within the database and reduce redundancy. The tissue and histology information in the reviewed papers is translated using the COSMIC classification system before entry into the database. It is possible that in some instances we have misunderstood terminology and hence misclassified mutations. Moreover, some users may not favour our classification. In general, however, we have aimed to retain as much useful information as possible, whilst providing a relatively simple classification with generally understood terminology.

The COSMIC classification system is available as a tab delimited text or Excel file in the Download section below. Every sample is defined by both tissue and histology. The example below shows how a paper definition would be translated into a COSMIC definition.

    Type                  Paper Definition   COSMIC Definition
    Site primary          colon              large intestine
    Site subtype 1        descending         colon
    Site subtype 2        NS                 descending
    Histology             carcinoma          carcinoma
    Histology subtype 1   polypoid type      adenocarcinoma
    Histology subtype 2   with adenoma       NS
    Histology subtype 3   NS                 NS

The COSMIC classification system was created in close collaboration with Adrienne Flanagan and Ahmet Dogan from the Royal Free and University College Medical School.


Classification Information

Comma Separated Values File