An anti-cancer substance is administered via the patient's blood ex vivo and in line by establishing a connection between the patient and a device having a chamber containing the anti-cancer substance. The patient's blood in the chamber and the anti-cancer substance interact so that immune cells in the blood (1) are activated to produce an immune response in the patient, or (2) are pre-armed by attaching to the cells antibodies, or (3) both. After activating or pre-arming the cells, the patient's treated blood is returned to the patient. The anti-cancer substance may be within the chamber prior to drawing the patient's blood into the chamber, may be introduced into the chamber after drawing the patient's blood into the chamber, or may be introduced into the chamber concurrent with the introduction of the patient's blood into the chamber. The connection is terminated after returning to the patient's blood including the activated or pre-armed cells.
