The effect of chemotherapy on acute leukemia in the human

A study has been made of 178 patients with acute leukemia admitted consecutively to the Chemotherapy Service of the National Cancer Institute between Oct. 22, 1953, and Oct. 20, 1958. Response to chemotherapy and survival varied markedly according to the age of the patient and the morphologic type of leukemia. For patients with acute lymphocytic leukemia, both the frequency of hematologic response and survival were better for children (under age 20) than for adults (age 20 and over). For patients with acute myelocytic leukemia, the frequency and extent of response did not vary with age. The response and survival for these patients with myelocytic leukemia was similar to that of adults with lymphocytic leukemia. However, for patients having a complete remission, the median duration of the remissions was significantly longer for patients with myelocytic leukemia, than for adults with lymphocytic leukemia. The survival time for patients who had a response was substantially longer than that for patients who did not. However, if the total time each patient received chemotherapy which resulted in a response was subtracted from the survival time, the resulting survival curves were similar to those for patients who failed to respond to therapy, and similar to the survival pattern reported prior to 1948. Thus the risk of death during periods of active disease has not changed during the past 10 years and the improved survival can be attributed directly to the duration of the hematologic responses resulting from chemotherapy. The duration of hematologic response was directly related to the extent of the response. The response to subsequent courses of therapy was found to be independent of response to the first course of therapy. There was a trend toward shorter survival the higher the white count at the time of diagnosis, but there was no relation between presenting symptoms or time from symptoms to diagnosis and survival. These data document the alterations in the natural history of acute leukemia resulting from currently available chemotherapy and can be useful for comparison with data accumulated in the future when newer forms of therapy are available.