ABSTRACT
A new concept is presented that proposes that a certain threshold of antitumor immune memory plays an important role [1]
in the control of residual tumor cells that remain after most therapies and [2] for long-term survival of treated cancer patients. This immune memory is T cell based and most likely maintained by persisting tumor-associated antigen (TAA) from residual dormant tumor cells. Such immune memory was prominent in the bone marrow in animal tumor models as well as in cancer patients. Pre-existing antitumor memory T cells from cancer patients could be activated by stimulation with TAA-pulsed autologous dendritic cells (DC) or with virusinfected TAA expressing autologous tumor cell vaccine (ATVNDV). Antitumor vaccination with ATV-NDV caused augmentation of antitumor memory Delayed Hyper-sensitivity (DTH) responses. In a variety of Phase II vaccination studies, an optimal formulation of this vaccine could improve long-term survival beyond what is seen in conventional standard therapies. Possible reasons for differences in long-term survival of patients treated by immunotherapy vs. chemotherapy are being discussed.
