[Clinical significance of sequential monitoring minimal residual disease in childhood B-cell acute lymphoblastic leukemia].

OBJECTIVE

To study the clinical significance of sequentially monitoring minimal residual disease (MRD) in childhood B-cell acute lymphoblastic leukemia (B-ALL).

METHOD

Eighty one B-ALL cases were enrolled in the study from January 2004 to December 2009. Leukemia cell markers were detected by flow cytometry at diagnosis, then regularly followed-up.

RESULTS

Of 81 cases, 80 achieved complete remission (CR) after induction therapy, 5-year event-free survival (EFS) was (76.80 ± 5.70)%. Among them, the EFS was (89.40 ± 5.90)% in standard risk group and (66.99 ± 13.60)% in intermediate risk group. Eight cases were screened for leukemia markers for MRD monitoring and identified in 68; and 5-year EFS was (79.10 ± 6.20)% and (62.50 ± 15.10)% (P > 0.05, respectively). MRD detection at day 35 in induction therapy showed that 52 of 68 cases were MRD negative (leukemia cells < 0.01%), the 5-year EFS being (88.50 ± 4.90)%, and 16 were MRD positive (leukemia cells ≥ 0.01%), the 5-year EFS being (42.10 ± 20.10)% (P > 0.05). Univariate analysis confirmed that there was a correlation between MRD monitoring and risk stratification. MRD detection at day 55 showed that among the 52 day 35 MRD negative cases, 51 were still negative, 1 positive, among 16 day 35 MRD positive cases, 14 (87.50%) turned negative, 2 still positive. Of the 68 cases, 9 were MRD positive within one year after CR (3 relapsed), 4 MRD positive after one year (2 relapsed) and 55 MRD negative (4 relapsed) (P > 0.05).

CONCLUSIONS

Sequential monitoring MRD can find out treatment outcome and adjust therapy in time.