Experimental model of pulmonary metastasis treatment with IFNalpha.

Melanoma shows the high rates of mortality, preferentially by metastasis, and the failure of chemotherapy. We inoculated 30 B16F10 Swiss mice with 5 x 10(5) melanocytes. The mice were then inoculated with 150,000; 300,000; 600,000 and 1,200,000 IU/mouse of interferon alpha. A count of the metastatic nodules of the lung surface and the microscopic study were made by image analysis on five histological sections, calculating the implantation percentage and tumoral growth and invasion index. Treatment with the three highest doses of interferon alpha resulted in a dose-dependent reduction of the number of metastatic nodules and invaded area. A correlation existing between the parameters studied and the different antitumoral effects observed.