The Metabolism of Tumors in the Body

In this contribution we discuss the question of whether tumor cells in living animals can be killed off through lack of energy, and the related question of how the tumors are supplied with oxygen and glucose in the body. We assume it is understood that tumor cells obtain the energy required for their existence in two ways: by respiration and by fermentation. In respiration they burn organic materials to carbon dioxide and water; in fermentation they split glucose to lactic acid. All tumors so far tested behave fundamentally alike. There is no essential difference between the cancer cells of transplanted rat tumors and spontaneous tumors, sarcoma and carcinoma cells, and the tar carcinoma, and Rous sarcoma produced by filtrate. The fermentation of tumors was first found with cut pieces of tumor in vitro. I C. and G. Cori 2 demonstrated it in living animals as well. They determined the glucose and lactic acid in the axillary veins of hens having in one wing a Rous sarcoma, and found in 100 cc. of blood 23 mg. less glucose and 16 rag. more lactic acid on the tumor side than on the normal side. A corresponding experiment with a human fore-arm tumor showed in 100 cc. of blood 12 rag. less glucose and 9 rag. more lactic acid on the tumor side. In experiments on the nourishment of tumors through the blood stream, we, like Cori, determined the glucose and lactic acid in tumor veins. Our procedure differed from Cori's in that we compared tumor veins and arteries, not tumor veins and corresponding normal veins. Our differences were greater than Cori's because we went closer to