RESUMEN
BACKGROUND: Recently, the importance of immunologic subclassification based on surface marker expression of acute lymphoblastic leukemia (ALL) has been emphasized. The importance of immunophenotypic analysis of ALL has been documented by numerous studies, but study for survival rate of subgroups in the non-T-ALL was rarely documented in Korea. The aim of this study was to classify the non-T-ALL immunologically, and to compare the survival rates among the subgroups. MATERIALS AND METHODS: From April, 1987 to October, 1997, 142 patients diagnosed as non-T- ALL by immunophenotyping were classified into 6 subgroups, group I to group VI. Review of medical records were undertaken in 130 patients and analysed for survival rates. For the cases in whom CD20 not tested, classification was also undertaken into 4 groups. The survival analysis of immunophenotypic subgroups was carried out by Kaplan-Meier method and differences in survival rates were tested by the log-rank test. RESULTS: The 142 patients, which included patients in whom CD20 was not tested, were assigned into 4 groups as follows: Group I (2 cases, 1%), Group II (24 cases, 17%), Group III-V (110 cases, 78%), Group VI (6 cases, 4%). On the other hand, 113 patients in whom CD20 was tested, were assigned into 6 groups as follows: Group I (0 cases, 0%), Group II (22 cases, 20%), Group III (59 cases, 52%), Group IV (23 cases, 21%), Group V (3 cases, 3%), Group VI (5 cases, 4%). The result showed that median survival time was higher in Group III and Group III-V, and lower in Group VI. However, statistic difference was not seen for 6 subgroups, while in the study for 4 subgroups, statistic difference was seen (p=0.04). And in children, study for 6 subgroups and 4 subgroups showed statistic differences in survival rate. CONCLUSIONS: We conclude that immunophenotypic subclassification of Non-T-ALL is a valuable prognostic marker in children.