OBJECTIVETo explore the risk factors of acute lymphoblastic leukemia (ALL) recurrence in adult patients and establish a prognosis index (PI) calculation model in order to improve the prevention strategy of ALL in adults.

METHODS104 adult ALL patients from Blood Diseases Hospital & Chinese Academy of Medical Sciences between August 2008 and November 2011 were enrolled. COX proportional hazards regression stratified by Dummy variable was used to set up the prediction model; Kaplan-Meier method and Log-rank test were used to estimate and compare the survival. After calculated individual PI value, patients' expected survival should be estimated by groups.

RESULTSThe overall median survival of adult ALL patients was 22.00 months (95% CI 17.00-27.00). COX regression analysis showed that chemotherapy group patients had a higher risk of recurrence than of ASCT group while setting treatment as the dummy variable (RR=2.052, 95%CI 0.877-4.799, P=0.007). Stratified Analysis showed that the risk factors of B-ALL recurrence in adult patients included HGB <100 g/L (RR=0.186, 95% CI 0.068-0.512, P=0.001), CNSL (RR=7.767,95% CI 2.951- 20.433, P=0.001), number of consolidation chemotherapy<3 (RR=0.445, 95% CI 0.211-0.940, P=0.034) and Ph chromosome positive (RR=2.771, 95% CI 1.353-5.674, P=0.005). Grouped by the PI value, the expected survival of each individual patient could be estimated as PI=0.58 base.

CONCLUSIONHGB, CNSL, number of consolidation chemotherapy and Ph chromosome were independent risk factors of B-ALL recurrence in adult patients. PI value could predict the survival of adult ALL patients and provide reference for individual therapy and prognostic evaluation.