OBJECTIVETo analyze the therapeutic effect and the influencing factors of event-free survival (EFS) of childhood acute lymphoblastic leukemia (ALL) in Xiangya Hospital of Central South University and the First Affiliated Hospital of Guangxi Medical University.

METHODSAll the patients adopted chemotherapy according to therapeutic guideline revised by the Subspecialty Group of Hematology, The Society of Pediatrics, Chinese Medical Association for the second-time in 1998 (the Rongcheng ALL-98 Protocol). Kaplan-Meier method was used to estimate the survival rates of 188 patients who received therapy with good compliance. The differences of EFS between groups were assessed by Log-rank test. The independent influencing factors on EFS were analyzed by the Cox proportional hazards regression model.

RESULTSAfter receiving inductive treatment, 354 of 374 (93.6%) patients demonstrated a complete remission; 188 patients who received complete courses of treatment with good compliance showed (68.1 +/- 5.6)% five-year EFS. Meanwhile, the five-year EFS in standard-risk (SR) group and high-risk (HR) group were (75.2 +/- 6.0)% and (47.6 +/- 11.6)%, respectively. The total relapse rate was 10.6% and the median time to relapse was 13 months. Twenty-nine of 188 patients (15.4%) were dead, and 13 patients (7.0%) died from treatment-related complications. Independent adverse prognostic factors included risk grouping, t (9; 22)/bcr-abl gene and leukocyte count.

CONCLUSIONSThe total EFS of childhood ALL patients treated with Rongcheng ALL-98 Protocol in two hospitals was close to 70%. Therefore, it is necessary to evaluate risk factors and consider the grouping in more detail to reduce the treatment-related mortality and to increase the compliance of treatment which can ultimately improve the EFS.