[Analysis of therapeutic effectiveness of Nanfang ALL 99 protocol in childhood acute lymphoblastic leukemia patients].

Objective: With more precise diagnostic criteria and risk classifications, more effective therapy administered in clinical trials, and better supportive care, the outcome of children with acute lymphoblastic leukemia (ALL) has been improved dramatically. Today, approximately 80% of children treated for this disease in developed countries enjoy long-term event free survival (EFS) and in most instances, would be cured. In this study, treatment outcome of 82 childhood ALL patients in the hospital were analyzed, and ways for how to improve the EFS rate in childhood ALL were explored.

Methods: Eighty-two patients with ALL were enrolled into the Nanfang ALL 99 protocol which derived from German BFM ALL 95 and Hong Kong-Singapore acute lymphoblastic leukemia 97 (HK-SG ALL 97). Dexamethasone instead of hydrocortisone was used for triple intrathecal therapy. Standard at risk patients who had been irregularly treated in other hospitals for short periods of time were classified as at intermediate risk. When ANC was > or = 1.0 x 10(9)/L and platelet > or = 100 x 10(9)/L, chemotherapy was started. Life table method was used to estimate survival rate and statistical analysis was done by using software SPSS for Windows.

Results: From March 1999 to September 2003, 82 childhood ALL patients were treated with the Nanfang ALL 99 protocol and 78 (95.1%) patients attained complete remission (CR) in a median time of 33 days. Out of 82 patients, 13 patients dropped out of the the Nanfang ALL 99 protocol because of financial difficulty or other reasons. Sixty nine patients were consecutively treated with the Nanfang ALL 99 protocol. The overall EFS rate at 2 years, 3 years and 5 years were 91.3%, 85.9% and 75.2%, respectively, with a median observation duration of 34 months. Three patients died of complications (4.3%). The disease relapsed in 6 patients and they died finally.

Conclusion: The outcome of patients treated with the Nanfang ALL 99 protocol was favorable, and the mortality rate of this chemotherapeutic protocol was low. This protocol was well tolerated by Chinese patients and therefore the protocol is worthy of application in China.