CNS-directed therapy in childhood acute lymphoblastic leukaemia

Marked improvements in outcome with chemotherapy alone in paediatric acute myeloid leukemia: results of the United Kingdom Medical Research Council's 10th AML trial. MRC Childhood Leukaemia Working Party

359 eligible children with acute myeloid leukaemia (AML) entered the MRC AML 10 trial between May 1988 and March 1995. Patients received four courses of intensive induction and consolidation chemotherapy, with or without subsequent autologous (A-BMT) or allogeneic (allo-BMT) bone marrow transplant. There were randomized comparisons of thioguanine versus etoposide in induction and of A-BMT versus not. Allo-BMT was recommended for patients with a HLA-matched sibling and was evaluated by donor versus no donor comparison. The complete remission rate was 92%. In first remission there were 20 deaths during consolidation chemotherapy and 11 after BMT (8/61 allo-BMTs. 1/60 A-BMTs and 2/4 matched unrelated donor transplants). The relapse rate was low, decreasing from 26% in the first year to 2% in the fourth. Long-term outcome was excellent with survival at 7 years from entry of 56% and event-free survival of 48%. There were no significant differences between thioguanine and etoposide, whereas both A-BMT and allo-BMT reduced relapse risk but did not produce a significant survival benefit. It appears that over half the children entered into AML 10 are cured, a result which compares favourably with other reported series. We conclude that four courses of intensive chemotherapy are an effective approach to the treatment of paediatric AML, which avoids the acute toxicity and long-term side-effects of BMT and also avoids the need for prolonged maintenance therapy or cranial irradiation.

Soluble L-selectin increases in the cerebrospinal fluid prior to meningeal involvement in children with acute lymphoblastic leukemia

Soluble L-selectin was determined in the CSF samples of 20 children with CNS leukemia at the time they had blasts in CSF and/or clinical findings of CNS involvement; 17 CSF fluid samples were obtained from 17 of these 20 children, 29-91 days before the appearance of CSF cytological and/or clinical findings of CNS involvement; while 15 CSF samples were withdrawn from among the same group of children, after treatment of meningeal leukemia. In addition, CSF sL-selectin was also assayed in 17 children with ALL, who remained in complete remission at least for a year and, as controls, in 12 children without malignant or meningeal disorders. There was no significant difference in CSF sL-selectin levels between the children with ALL without evidence of meningeal involvement and the controls (1.34 +/- 0.21 ng/ml, 1.46 +/- 0.18 ng/ml respectively, p > 0.05). However, in children with CNS leukemia, not only at the time CNS involvement was diagnosed, but also 29-91 days before the diagnosis of CNS leukemia, the concentrations of the CSF sL-selectin (12.41 +/- 2.14 ng/ml, 7.70 +/- 1.60 ng/ml respectively) were significantly higher than those in controls (p < 0.001 and p < 0.01 respectively). After treatment and disappearance of the blasts in CSF, sL-selectin was found to be decreased and even normalized in the majority of children who had meningeal involvement (2.87 +/- 2.14 ng/ml). In 5 children, the CSF sL-selectin remained high, after the blasts in CSF had disappeared and CNS leukemia recurred within 3 months in 4 of these 5 children. In conclusion, assay of sL-selectin in CSF seems to be a good diagnostic tool in the detection of CNS involvement in children with ALL. This method may also be used as an indicator, in prediction of the CNS leukemia, which is going to develop.

Prolonged intrathecal chemotherapy replacing cranial irradiation in high-risk acute lymphatic leukaemia: long-term follow up with cerebral computed tomography scans and endocrinological studies

Cranial irradiation in children with acute lymphatic leukaemia (ALL) decreases the risk of CNS relapse but is associated with serious long-term side-effects. We present the long-term outcome of 21 children with high-risk ALL who received prolonged intrathecal chemotherapy instead of the recommended cranial irradiation. Intrathecal triple therapy (methotrexate, hydrocortisone, and cytarabine) was administered every 2nd month throughout the maintenance phase. The average number of courses of intrathecal methotrexate was 8.7 and of triple 9.0. The 5-year event-free survival was 79%. No CNS relapses occurred. CT scan was performed at diagnosis, at cessation of therapy, and 3 years thereafter. No density abnormalities, pathological contrast enhancement, ventricular dilatation, or calcifications were found. One child showed cortical atrophy both at diagnosis and at cessation of therapy. There was a slight decrease in height SDS with time but no change in weight SDS. Delayed bone age was found in 5 children. No abnormalities of growth hormone, thyroid, adrenal, or gonadal function were observed.

CONCLUSION

The study indicates that extended intrathecal chemotherapy in children with high-risk ALL may provide an effective protection from CNS relapses and is associated with a low risk of long-term side-effects.