Comparison of simultaneously incurred damage to bone marrow and tumor tissue of animals treated with anticancer agents.

The suppression of tumor tissue (as measured by tumor weight) and the destruction of bone marrow (as measured by the number of nucleated cells per mouse femur) were determined at several dose levels of each of the compounds investigated. The least reduction in the quantity of marrow cells occurred in the animals treated with 3',5'-dichloroaminopterin and mitomycin C. In contrast, marked suppression of tumor tissue was found in the same animals. Marked marrow and tumor suppression occurred in animals treated with thioTEPA. Mitomycin C was between dichloroaminopterin and thioTEPA in the separation of marrow and tumor damage. 6-Mercaptopurine caused the same effect on S-180 tumor tissue as on the bone marrow. The daily changes in tumor weight and marrow count of animals treated with 5 mg/kg of th ioTEPA/day for 6 days were described. Of these two tissues, tumor or marrow, the latter bore the brunt of the deleterious effects. The count was markedly lower on the day of harvest than that found on day zero. In contrast, the weight of the tumor tissue from treated animals was approximately the same as that initially found. The volume of the femur cavity of the 18-gm. male C3H mouse was found to be 5.~ cu. ram., and the number of nucleated cells per femur was 9.5 (8.~-10.8) X 106.