Henry Ford Hospital Medical Journal


Spontaneous mammary carcinoma in C3H mice is preceded by premalignant hyperplastic alveolar nodules. When a primary tumor is evident, examination of the other mammae will reveal a number of microscopic precancerous lesions in various stages of transformation to overt malignant tumors. In an effort to inhibit the development of additional malignant tumors after surgical removal of the first apparent tumor, we treated female C3H/HeJ mice with subcutaneous injections of levamisole (0.6 mg per kg of body weight) on a twice weekly regimen. All further tumors were surgically excised when they became palpable. The surgical excision of bulk tumor burden, immunorestoration by levamisole, and the presence in the tumor cells of immunogenic surface antigens related to the virus all might be expected to enhance immunodulation of tumor cell growth or immunorejection of tumor cells. Immune activity measured by assaying macrophage migration inhibition factor, extractable from splenocytes, was significantly greater in the levamisole-treated mice than in the controls throughout the experiment. Although fewer tumors developed in the treated animals during the first eight weeks, this apparent effect of immunopertubation was only transitory. By the end of 14 weeks, there was no longer a statistically significant difference in cumulative tumor index between the two groups.