Effect of combination immunochemotherapy with an organogermanium compound, Ge-132, and antitumor agents on C57BL/6 mice bearing Lewis lung carcinoma (3LL)

The antitumor effect of combination immunochemotherapy with Ge-132 and antitumor agent was studied using C57BL/6 mice bearing Lewis lung carcinoma (3LL). Ge-132 was administered orally at a daily dose of 100 mg/kg. Antitumor agents were administered intraperitoneally once a week. Initially, the effect of combination immunochemotherapy with Ge-132 and 5-fluorouracil (5-FU) was studied on 3LL local tumor growth, pulmonary metastases, survival, delayed type hypersensitivity (DTH) and body weight in tumor-bearing mice, and the following results were obtained: Inhibition of tumor growth in the combined group; Enhanced anti-metastatic effect; Prolonged survival time, and; Recovery of loss of both DTH and body weight as a result of combination therapy. These antitumor effects were also obtained by adoptive transfer of Ge-132-stimulated splenocytes in 5-FU-treated mice bearing 3LL. These results therefore suggest that the effects of Ge-132 were expressed through modification of immunocytes. Furthermore, Ge-132 enhanced the antitumor activity of bleomycin as well as that of 5-FU. These facts suggested that Ge-132 is useful for antitumor combination immunochemotherapy.