[Two cases of prostate cancer associated with acute myeloid leukemia presenting as thrombocytopenia during endocrine therapy]

Prostate is one of the most common sites of multiple primary cancer (MPC). We herein present two cases of prostate cancer associated with acute myeloid leukemia (AML) presenting as thrombocytopenia during endocrine therapy. After a diagnosis of prostate cancer (stage D2) was made, our patients received endocrine treatment with fosfestrol followed by a luteinizing hormone-releasing hormone (LH-RH) analogue and bicaltamide. Thrombocytopenia appeared 8 months and 10 months after the initiation of endocrine therapy, respectively. Because suspensions of bicaltamide resulted in further deterioration of thrombocytopenia, bone marrow aspirations were done with hematological examination revealing features of the M2 subtype of AML. Review of MPC with prostate cancer in the literature suggested that the combination of prostate cancer and AML was rare.