Search

Abstract: Introduction: Advanced colon cancer patients, acquired-chemotherapy resistant and in progression, are therapeutically terminal. We tested a recently described medical procedure using a thermostable autologous hemoderivative purported to inhibit tumor growth possibly through an immunological mechanism of action. Patients and Methods: Metastatic colon cancer patients chemotherapy-resistant, high CEA plasma levels, in progression, were 2-group randomized. Group 1 received the test procedure and Group 2 adequate control measures. During an 8-mo follow-up period (n=101), tumor growth, number of cases attaining clinical nonprogressive status, and mortality were assessed monthly. Immunological effect was assessed by delayed-type hypersensitivity test and lymphocyte proliferation assay. Responding-tumors histopathologies were studied. Results and Discussion: In a significant number of cases, the test procedure promoted inhibition of tumor growth, nonprogressive disease status, and lower cumulative mortality. These clinical results were associated with polyvalent immunization against several tested antigens: the hemoderivative used for treatment, the blood tumor markers, and the regulatory lymphocyte population (CD4+CD25+). Interference with this regulatory activity could explain the selective autoimmunity suggested by the histopathology findings in responding tumors. Conclusion: The autologous hemoderivative tested is antigenically polyvalent and promotes a polytargeted immune response associated with a tumor antiprogressive effect, consequently, acting as an autologous hemoderivative cancer vaccine.