Objective   To compare the efficacy and safety of arsenic trioxide (ATO) with all-trans retinoic acid (ATRA) for the treatment of acute promyelocytic leukemia (APL).   Methods   We searched the database of Cochrane Library (Issue 1

2009)

CENTRAL (1970 to 2009)

Medline (1978 to 2008)

EMBASE (1950 to 2009)

CBM (1978 to 2008)

CNKI (1994 to 2008) and CMAC (1994 to 2008). We also searched the Meta register

Conference Proceedings of American Society of Hematology (1946 to 2008) and American Society of Clinical Oncology (2004 to 2008) on the internet for grey literature. We had searched the related journals in the library of Third Military Medical University

too. We included randomized controlled trials which compared ATO with ATRA for the treatment of APL. We adopt complete remission rate

overall survival rate

disease-free survival rate

time to complete remission

relapse rate

mortality and adverse reactions as result indicators. Data were entered and analyzed with the Cochrane review manager software (Revman 5.0).   Results   Four eligible randomized controlled trials (RCTs) were included (n=243). All the RCTs were methodologically graded as B. They all are focusing on the comparison of ATO monotherapy with ATRA monotherapy in treating newly diagnosed APL patients. Meta analysis showed that effect index for complete remission

2-year disease-free survival

time to complete remission

relapse rate and mortality was 0.96 (0.50

1.86)

2.76 (0.71

10.66）

－1.30 d (－1.83

－0.78)

0.86 (0.45

1.63)

and 1.15 (0.45

2.95)

respectively. All indicated no statistically significant difference. Effect index for incidence of liver dysfunction was 3.03 (1.25

7.37)

which showed statistically significant difference between ATO group and ATRA group.   Conclusion   ATO is not superior to ATRA in treating newly diagnosed APL patients regarding complete remission

disease-free survival rate

time to complete remission

relapse rate and mortality. What is worse

it will increase the incidence of liver dysfunction during treatment. Due to limitation of included trials

this conclusion need to be validated by further studies.