The ongoing development of
monoclonal antibody technology may eventually lead to the selective targeting of human
carcinoma lesions by MAbs conjugated with a variety of
cytotoxic agents (i.e.,
radionuclides, drugs, etc.). The
antigen phenotype of the
carcinoma cell will play an important role in the efficacy of the MAbs. Clearly, the human
tumor antigens that are expressed on all
carcinoma cells, and with a high
antigen density, should provide the optimal target for the MAbs. More often than not, however, the human
tumor antigens whose expression is highly selective for human
tumor cells will also exhibit a certain degree of heterogeneity. Therefore, the ability of
interferon to augment the level of expression of human
tumor antigens such as
TAG-72 and CEA, may play an important role in an adjuvant setting for immunoscintigraphy and/or
immunotherapy. More recent observations have demonstrated that
interferon treatment can also enhance the amount of
TAG-72 and CEA secreted by the
tumor cell. The ability of
interferon to enhance the shedding of both
TAG-72 and CEA could be of particular importance since recent reports suggest that their presence in the sera of patients diagnosed with gastrointestinal
adenocarcinoma may be complementary and that the ability to increase either marker may facilitate earlier diagnosis of recurrent disease. It is conceivable that in subsequent years effective approaches to monitoring and/or treating
malignancies may include a new combination of
biological/immunological
therapy.