When the cause of death is cancer, it is very important to report the, Site of the cancer.  Also state whether it is primary or secondary cancer.  If it is secondary, state the primary site, if known.  If it is unknown, state “primary unknown” as the underlying cause of death.  Also state the histological type, such as adenocarcinoma, if it is known.  If the stage – such as Stage 3B breast cancer – is known, it should be reported.