Antitumor effect of the organogermanium compound Ge-132 on the Lewis lung carcinoma (3LL) in C57BL/6 (B6) mice.

Effects of the organogermanium compound Ge-132 (i.p.) were examined on the 3LL local tumor (1 X 10(5)/mouse, s.c.) and its pulmonary metastases in B6 mice. A characteristic feature of its action was the preferential antimetastatic effect under strictly defined conditions. Either inhibition or facilitation was observed depending on the treatment schedules; 7 daily doses of 100 mg/kg yielded the inhibition ratio 49% when started from day 1, whereas the treatment from day 8 resulted in the ratio -99%. The maximum inhibition was obtained at 100 mg/kg. The postsurgical-adjuvant treatment with Ge-132 was of no beneficial effect. The local tumor growth was affected only marginally and temporarily. When inoculum size was minimized (1 X 10(4)), a single dose of 300 mg/kg on day 1, but not on day 8, was effective in prolonging the latency before tumor take. The antitumor action of Ge-132 was discussed with reference to its interferon (IFN)-inducing activity.