Influence of Tumor Size and Surgical Resection on Cell-Mediated Immunity in Mice2

Abstract

Tumor-specific immunity and general lymphoid cell competence were assessed in mice with 3-methylcholanthrene- induced transplantable tumors at various stages of development and after surgical resection. A significant level of tumor-specific immunity developed before palpable tumors were observed. The level of immunity increased slightly as tumors became palpable, then decreased, and finally disappeared completely when tumors were >10% of the total body weight. Resection rapidly increased the level of immunity. The response to both T- and B-cell mitogens decreased progressively with increasing tumor size but returned to normal levels after resection.