[Therapy-related myeloid neoplasms after successful treatment for acute promyelocytic leukemia: a report of four cases and literature review].

To investigate the clinical characteristics, diagnosis, treatment and prognosis of therapy-related myeloid neoplasms (t-MNs) after successful treatment for acute promyelocytic leukemia (APL) . Clinical data of 4 patients, diagnosed as t-MNs secondary to APL at Hematology Hospital of Chinese Academy of Medical Sciences from October 2012 to January 2019, were collected retrospectively. T-MNs related literature was reviewed. The 4 cases were all females, with the median age 42 (range 40-53) years old at the diagnosis of APL. Regarding the induction and consolidation regimens, 3 patients received all-trans retinoid acid (ATRA) and arsenic trioxide (ATO) combined with anthracycline/anthraquinone and/or cytosine. One patient only received ATRA and other auxiliary drugs. Alkylating agents were not administrated. The 4 patients developed t-MNs 40 to 43 months after complete remission (CR) of APL, including 1 case of therapy-related myelodysplastic syndrome (t-MDS) and 3 cases of acute myeloid leukemia (t-AML) . The PML-RARα fusion genes were all negative when t-MNs developed. The three patients with t-AML were treated with 3 to 4 re-induction regimens, one of whom underwent allogeneic hematopoietic stem cell transplantation (allo-HSCT) after complete remission (CR) . One patient with t-MDS received hypomethylating agents. After a median follow-up of 54.5 (48-62) months, 2 patients with t-AML died, the median overall survival after t-MN was 12 (5-18) months. From 1989 to 2018, a total of 63 t-MN cases were reported in the literature. Therefore, 67 cases were analyzed when four patients in our center were added, including 27 males and 40 females with median age 52.5 (15-76) years. The median latency was 39 (12-126) months and the median overall survival after diagnosis of t-MN was 10 (1-39) months. Although rare, t-MNs may occur after successful control of APL. There are no existing guidelines for prevention and treatment of t-MNs, which have very poor prognosis. If cytopenia or other abnormalities of peripheral blood cells develop after 3 years of APL, t-MNs should be considered as a differential diagnosis.