California Cancer Reporting System Standards Volume I: Abstracting and Coding Procedures
This data item identifies the patient and the tumor. Each patient entered in a reporting facility registry is assigned a unique accession number, and each primary diagnosed for that patient is assigned a sequence number. The accession number never changes and is never reassigned, even if a patient is removed from the registry. The accession number may be auto-generated by some abstracting vendors.
The first four digits of the accession number represent the year the patient was first seen at the reporting facility. See Year First Seen.
The last five digits represent the approximate chronological order of the abstracts prepared for that year.
Examples:
If the patient was admitted or the tumor was diagnosed on February 11, 2005, the first four digits are 2005. If the abstract for the reported tumor was the 285th prepared for 2005, the accession number is 200500285.
Two abstracts are being prepared for a patient with one primary tumor diagnosed in 2004 and another in 2006. The first four digits of the accession number are 2004 and the next five represent the abstract's place in the chronological order of cases reported for 2004. The same accession number must be used for the second and subsequent abstracts. (However, the year first seen for the first tumor is 2004 and for the second it is 2006.)