Adjuvant radioimmunotherapy for micrometastases: A strategy for cancer cure

Abstract

Cancer kills when present methods fail to destroy malignant cells participating in metastatic spread throughout the body. Rarely are current methods successful in controlling these micrometastases once hematologic spread of primary tumor occurs. We have determined by analysis of existing biological and physical data that it is possible to destroy tumor cells including, most importantly, isolated cells distributed within the hematologic system without excessive normal tissue damage using systemically administered radiolabeled antibody. Since the red bone marrow has apertures and a poorly developed basement membrane any plasma-borne antibody rapidly equilibrates with its extracellular space. Direct access of plasma-borne labeled antibody to the tumor cell membrane in the hematologic system is therefore provided. This is not the case for other normal tissues because the capillary basement membrane in these tissues effectively restricts the entry of radiolabeled antibody into tissue extra-cellular space (half-times = 10–50 h), thus effectively minimizing the potential hazard of normal cell surface localization of labeled antibody due to cross-reactivity with normal tissue. Cross-reactivity with any non-hemato1ogic normal tissue for antibodies labeled with short-lived radioisotopes can, therefore, be neglected.