Comparative chemotherapeutic investigations on transplanted and autochthonous acute rat leukemias

The effect of a clinically active drug combination (vincristine, adriamycin, cytosine arabinoside) against (1) a transplanted acute rat leukemia (L 5222) and (2) autochthonous acute rat leukemias is compared in a non-toxic dose range. After four therapy cycles without therapy-free intervals, the animals with transplanted leukemia died; remissions were not achieved. In all rats with autochthonous leukemia the same treatment that was additionally interrupted by therapy-free intervals of 1 week caused complete remissions. The different reactions of both leukemia types to this treatment are mainly due to their kinetic differences. The comparability of transplanted and autochtonous rat leukemias with human acute leukemia is discussed.