Date of initiation of the first therapy for the cancer being reported, using the CoC definition of first course. The date of first treatment includes the date a decision was made not to treat the patient. See
FORDS for details. See Chapter V, Unresolved Issues for further discussion of the difference between SEER and CoC items. See Chapter X for date format. Use Date 1st Crs RX CoC Flag [1271] if there is no appropriate or known date for this item.
Formerly Date of 1st Crs RX--CoC.