Lysozyme levels and macrophage content of tumor tissue in C3H mice bearing fibrosarcoma transplants treated by radiation and Corynebacterium parvum.

Abstract

Abstract Serum levels of lysozyme (SL) were measured in C3H mice bearing early generation isotransplants of a methylcholanthrene induced fibrosarcoma (FSa) and of a spontaneous mammary carcinoma (MCa). SL increased with growth of FSa beyond 1000 mm 3 ; in MCa mice, SL was independent of tumor volume. SL could not predict control probability for the FSa after treatment by irradiation or intravenous Corynebacterium parvum . The macrophage content of FSa decreased as tumors reached massive size; few macrophages were found in FSa growing in immunosuppressed hosts and in MCa in normal hosts. The administration of C. parvum did not substantially increase the macrophage infiltration of either FSa or MCa. The concentration of lysozyme per unit tumor volume increased slightly with progressive growth of the FSa, was low in FSa in immunosuppressed hosts and increased slightly in FSa mice given C. parvum . Macrophage content and TL of 8 mm diameter FSa did not predict control probability after treatment with irradiation or C. parvum. Moderate differences in macrophage content of immunogenic FSa may reflect degrees of efficiency of host response, but such differences are insufficient to serve as prognostic indicators. Macrophage content of tumors and TL may be of value in identifying weakly immunogenic tumors or hosts which mount only a feeble response.