Antitumoral effect of a vaccination procedure with an autologous hemoderivative.

Lately, the promising results obtained with autologous cancer vaccines are stimulating new research in the old field of cancer immunotherapy. This paper describes the development of a procedure previously reported by us that is used to obtain an autologous hemoderivative with antitumoral properties. The procedure has been tested in a phase I-II, randomized, controlled clinical trial of 28 cancer patients with different primary malignancies in metastatic and chemotherapy-resistant stages. The histology of the lesions that responded to this treatment was consistent with the characteristic histology observed in malignant lesions treated with a similar antitumoral hemoderivative: proliferation of stromal connective tissue, T-lymphocyte infiltration, and a reduction in the amount of tumor cells and blood vessels. We concluded that vaccination had elicited an immune response because a delayed-type hypersensitivity test made with the autologous hemoderivative produced a significantly more intense response in the responding treated patients. We propose that an immune mechanism acting on tumor cells and/or the regulatory system for stromal growth explains the histological results observed. The use of blood to obtain the immunogen allows vaccination to be repeated, so this method could avoid tumor escape responses due to mutations in the antigen library of the tumor. The results of our study justify further research to optimize the antitumoral effect of vaccination.