Dissemination and proliferation of intravenously injected murine, syngeneic T lymphoma cells.

BALB/c mice were inoculated intravenously with syngeneic T lymphoma cells. Dissemination and proliferation of malignant cells in vitro were determined from time of cell injection to the time of death of the animal, using an agar medium in which only tumor cells grew. Tumor cells were detected in kidney from day 7, and in liver, lungs and ovaries from days 9-12. The myeloid-lymphatic system was only sparsely invaded. Three weeks after injection the animals died of general metastases, and colonies could be grown from all organs. Peripheral blood tumor cells colonies were grown in quantities of 1-2% on injected cells during the first hour. They then disappeared from blood, but reappeared 2-3 weeks later. Within the first 15 min after i.v. infections of vitro labelled tritiated-thymidine tumor cells, 45% of the radioactivity was recovered from lungs and 40% from the liver. After this time the activity gradually declined. Only about 1% of the initial activity of the injected cells was found in the spleen, kidney and brain during the first 24 hours. Blood glow of the organs was examined by means of indicator fractionation. Highest flow rates were measured in liver, kidney, brain and lungs. Thus, the sites of metastases after tumor cell injection were determined neither by the initial deposition of tumor cells, nor by blood flow rates through the organs. This result shows that cellular interaction between neoplastic cells and the immediate environment must be major determinants in the development of metastases.