After removal of the primary tumor node, tumor-specific activity appears in the serum that blocks tumor growth in mice. This activity is observed at the time interval when activity of the tumor growth-stimulating factor is not determined. Administration of blood serum (0.1 ml) from mice with removed tumor to mice with CaO1 adenocarcinoma for 14 days led first to a stop of its growth, and then to tumor regression. The animals cured of adenocarcinoma lived for at least one year without signs of relapse. The cured animals did not develop resistance to repeated tumor transplantation. Repeated transplantation led to the growth of the new tumor. No cellular immune response was observed on histological slides of the regressing tumor. It was concluded that a serum factor is required for the growth of a tumor in the body and the state of the serum with blocked activity of this tumor-stimulating factor can be used for tumor treatment in oncology patients. This is the first result in the syngeneic system, when the tumor was cured by syngeneic serum proteins.
Keywords: blood serum proteins; removal of primary tumor; tumor cure.
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