California Cancer Reporting System Standards Volume I: Abstracting and Coding Procedures for Hospitals
When two or more of the patient's tumors were diagnosed simultaneously, assign the lowest sequence number to the one with the worst prognosis. To determine worst prognosis you can review the following topics (or entire topic area).
See Section V.5, Stage at Diagnosis
See Section V.3.7 Grade and Differentiation.
If these sections do not reveal the worst prognosis, assign sequence numbers in the order in which the abstracts are prepared.
A patient's medical record shows a history of three primary malignant (reportable) tumors in the past and two simultaneously diagnosed recent malignant tumors, one of which is the subject of this report, for a total of five malignancies. The stage of the tumor being reported is regional, whereas the stage of the second of the multiple tumors is localized, a better prognosis. Assign sequence number 04 to the tumor being reported. The number for the second multiple primary is 05.