Dr. Michael Har-Noy of Immunovative Therapies, a biotech company founded in Israel in 2004, says that a common misconception is that cancer is a disease of the weakened immune system.
Dr. Michael Har-Noy explains that when a normal cell becomes a tumor cell, changes occurring in the expression of surface antigens give rise to tumor associated antigens (TAAs) that theoretically could be detected by one’s immune system. Ehrlich, in 1909, first proposed that one’s immune system protected against cancer, a concept adapted in the 1950s by Lewis Thomas and then later by Sir Macfarlane Burnet, who proposed that a patient’s immune system had a “surveillance” mechanism for tracking down and killing precancerous and cancerous cells. The basis of this hypothesis is that tumors constantly arise in one’s body and that one’s immune system must recognize and destroy cells that have TAAs on their surface.
This theory goes on to predict that in cases where the patient’s immune system is suppressed, the surveillance mechanism is then compromised, and the cancer cells grow out of control and clinical disease becomes detectable. This is the theory behind the concept that the patient’s immune system in cancer cases is weak, and that this immune system must be reinforced to attack the cancer effectively.
Dr. Michael Har-Noy and Immunovative Theories believe that there is, however much evidence to the contrary. While a small number of the rarer cancers occur in immune compromised individuals, most human malignant tumors are found in patients with intact immune systems. Also, many cancers, especially epithelial cell tumors, have a significant component of inflammatory cells. This includes diverse leukocyte infiltrates of macrophages, neutrophils, eosinophils, and mast cells, frequently in the presence of lymphocytes. Malignant tumors are typically densely infiltrated with immune cells, which argues against inadequate immune system recognition of TAAs.
Furthermore, many previous attempts to bolster the normal immune response enhanced rather than suppressed growth of the cancer. For example, in mice, a newly induced tumor of both mesenchymal and epithelial origin grows faster if it precipitates a reaction from the patient’s immune system. Highly immunogenic cancers left undisturbed in their original hosts often grow faster than tumors that stimulate little or no immune response. Therefore, the idea that tumors are “invisible” to the patient’s immune system and that this immune system needs to be augmented appears to be incorrect.
The problem may be that the patient’s immune response to the tumor is the wrong kind of response. Dr. Michael Har-Noy and his team at Immunovative Theories believe that in attempting to boost an immunologic response that has already failed to protect the patient against cancer, tumor growth may be enhanced rather than suppressed. This is probably why most immunologic cancer treatments to date have been ineffective.