Unexpected response of hormone-refractory prostate cancer to treatment with an antileukemic chemotherapy regimen.

Our patient was a 61-year-old man with hormone-refractory prostate cancer and a rapidly rising serum prostate-specific antigen level. During the course of therapy for prostate cancer, abnormal blood counts and subsequent bone marrow biopsy led to a diagnosis of acute lymphoblastic leukemia. He was treated with a chemotherapeutic regimen in standard use for lymphoblastic leukemia, which resulted in an unusual response of his prostate cancer, with declining serum prostate-specific antigen levels that had reached undetectable levels at the time of the patient's death from acute sepsis and leukemic relapse. Autopsy showed minimal evidence of prostate cancer, localized to the prostate.