Improved outcome of acute lymphoblastic leukaemia treated by delayed intensification in Hong Kong children: HKALL97 study.

OBJECTIVE: To study the outcome of children with acute lymphoblastic leukaemia who were treated using a protocol including one or two delayed intensifications. DESIGN: Prospective single-arm multicentre study. SETTING: Five designated children cancer units of the Hospital Authority of Hong Kong. PATIENTS: Children aged between 1 and 17.9 years with newly diagnosed acute lymphoblastic leukaemia seen from November 1997 to December 2002. INTERVENTION: Chemotherapy was modified from a German Berlin-Frankfurt-Muenster 95 (BFM95) protocol that included a delayed intensification similar to the induction phase repeated 5 months after diagnosis. High-risk patients were given double delayed intensification. MAIN OUTCOME MEASURES: Overall survival and event-free survival of the whole group and the three risk groups (standard-, intermediate-, and high-risk groups), and comparison with historical controls. RESULTS: A total of 171 patients were recruited with a median age at diagnosis of 5.57 years (range, 1.15-17.85 years). The induction remission rate was 95.3% and non-leukaemia mortality during remission was 2.3%. At 4 years, the relapse rate of this (HKALL97) study was significantly lower than that of the HKALL93 study (15.7 vs 37.3%; P<0.001). The 4-year overall survival of HKALL97 and HKALL93 studies were 86.5% and 81.8%, respectively (P=0.51). The 4-year event-free survival for HKALL97 and HKALL93 studies were 79% and 65%, respectively (P=0.007). Nonetheless the difference of event-free survival was most remarkable in the intermediate-risk group: 75.6% and 53.1% for HKALL97 and HKALL93 studies, respectively (P=0.06). CONCLUSION: A more intensive delayed consolidation phase improved the outcome for children with acute lymphoblastic leukaemia by reducing relapses at 4 years. The early treatment complications were manageable and non-leukaemia mortality during remission remained low.

Multicentric osteosarcoma presenting as retrobulbar mass: a diagnostic enigma.

Osteosarcoma is the most common primary malignant bone tumor of children and adolescents. It often presents as a solitary lesion; multicentric osteosarcoma with synchronous lesions occurring at multiple skeletal sites is very rare. We report a 9-year-old boy with multicentric osteosarcoma who presented with a left retrobulbar non-sclerotic mass. The multiple lesions in bone were mostly non-sclerotic on radiological examination except for a single lesion in the left tibia. Biopsy of the retrobulbar mass showed an unclassifiable poorly differentiated malignant tumor. Marrow aspiration smears showed many large, often segregated, round cells that expressed NB84a. However, trephine biopsy showed the formation of tumoral osteoid by the malignant cells, finally permitting the definitive diagnosis of osteosarcoma to be made. A hypertetraploid clone with complex structural abnormalities was demonstrated by cytogenetic study.

P53 expression in colorectal carcinoma: the University of Malaya Medical Centre's experience.

Loss of P53 function is regarded as one of the critical steps in colorectal carcinogenesis. This study determines the P53 expression pattern of colorectal carcinoma in a cohort of 116 local patients. There was no significant relationship between overexpression of P53 with tumour stage (p=-0.209, chi square test) and grade (p=0.877, chi square test). Survival analysis using Kaplan-Meier procedure did not show significant relationship between P53 positivity with overall recurrence-free and survival outcome (p=0.3322 and 0.921 respectively; log rank test). Long-term follow-up may give a better evaluation on the prognostic value of P53 overexpression in colorectal carcinoma.

Treatment of acute lymphoblastic leukemia in Hong Kong children: HKALL 93 study.

A population-based multicentre study for childhood acute lymphoblastic leukemia (ALL) was conducted in Hong Kong from 1993 to 1997. One hundred and forty-five newly diagnosed ALL patients were treated by the HKALL 93 protocol. Patients were stratified into three risk groups according to age, presenting white cell count, immunophenotyping and cytogenetic study. The patients received the same induction and early and late intensification at week 5 and week 20. Fifty-eight standard risk (SR) patients received regular intrathecal methotrexate as CNS preventive therapy, while 49 intermediate risk (IR) patients received high dose intravenous methotrexate and regular intrathecal methotrexate. Thirty-eight high risk (HR) patients were treated with prophylactic cranial irradiation and an additional intensification block at week 35. The induction remission rate was 97.2% with 2% induction death. Two patients died during first complete remission. Relapse occurred in 20.7, 42.9 and 42.1% of SR, IR and HR patients respectively. By multivariate logistic regression, age> or =10 years and white cell count> or =100 x 10(9)/l were the two significant variables accounting for mortality. The 5-year overall and event-free survival of the whole group was 81.3 and 62.6% respectively. According to risk groups, the event-free survival was 79, 49 and 61% for SR, IR and HR patients respectively, while the overall survival was 96, 73 and 68% for SR, IR and HR patients respectively. In conclusion, the treatment protocol had low treatment-related mortality but was associated with a rather high relapse rate, especially in IR patients. Salvage therapy achieved sustained second remission in some patients. More intensive treatment especially a late intensification is required to improve the outcome.

Treatment of hemoglobin Bart's hydrops with bone marrow transplantation.

A 21-month-old girl with hemoglobin Bart's hydrops received bone marrow transplantation (BMT) from a matched sibling. No major BMT-related complications developed. Hemoglobin levels remained greater than 10 gm/dl for 20 months without blood transfusion support despite the presence of residual host hemopoietic cells from 2 months after BMT. We suggest consideration of this therapeutic option for surviving patients.

Clustering of childhood leukaemia in Hong Kong: association with the childhood peak and common acute lymphoblastic leukaemia and with population mixing.

Incidence data of childhood leukaemia (CL) in Hong Kong (1984-90) have been analysed for evidence of variation between small areas. All cases (n=261) were classified by morphological cell type, with the majority (n=205) being acute lymphoblastic leukaemia (ALL), and haematological review has permitted immunophenotypic classification for 73% of these. The data have been examined for evidence of spatial clustering within small census areas (TPUs) and for association with population mixing, with attention focused on those subgroups (especially the childhood peak of ALL--taken here to be diagnoses in children from 24 months up to the seventh birthday--and common ALL) which, it has been hypothesized, may be caused by unusual patterns of exposure and response to common infections. For the whole of Hong Kong, there was evidence of spatial clustering of ALL at ages 0-4 years (P = 0.09) and in the childhood peak (P<0.05). When these analyses were restricted to TPUs where extreme population mixing may have occurred, overall incidence was elevated and significant evidence of clustering was found for ALL (P<0.007) at these ages and for the common ALL in the childhood peak (P = 0.032). Replication of the analyses for subsets of leukaemia that were not dominated by the childhood peak of ALL found no evidence of clustering. This is the first investigation of an association between population mixing and childhood leukaemia in Asia and the first to include clustering and to consider particular subsets. The results are supportive of the 'infectious' aetiology hypothesis for subsets of childhood leukaemia, specifically common ALL in the childhood peak.

Detection of clonal Epstein-Barr virus in malignant proliferation of peripheral blood CD3+ CD8+ T cells.

Epstein Barr virus (EBV) DNA was detected in a monoclonal proliferation of T cells in a three-year-old girl who presented with a history of fever, hepatosplenomegaly, and generalised lymphadenopathy. The disease ran a rapid, fulminant course and the patient died 11 days after presentation. Examination of the blood showed a lymphocytosis of 50 x 10(9)/l with all the cells showing the morphology of large granular lymphocytes. These cells were CD2+3+8+25+. Cytogenetic studies showed the presence of a 6q- clone. Southern blotting and hybridisation with a constant region probe for the T-cell receptor (TCR) beta chain gene showed clonal rearrangement of the TCR beta gene. Hybridisation of the Southern blot to the EBV XhoI probe revealed a clonal pattern of episomal EBV DNA. Our results establish the association between clonal EBV infection to a malignant proliferation of peripheral blood CD8+ T cells.

Anaplastic large cell Ki-1 lymphoma involving bone marrow: marrow findings and association with reactive hemophagocytosis.

This report describes the bone marrow findings in four patients whose marrow was involved by anaplastic large-cell Ki-1 lymphoma, an uncommon event in this type of lymphoma. In the marrow aspirate smears, the involvement was subtle, and was in the form of isolated large cells with irregular nuclear configuration, coarse chromatin, prominent nucleoli, and basophilic cytoplasm which might be vacuolated. One case showed paradoxically massive involvement in the trephine biopsy taken from the same site as the marrow aspirate. Reactive histiocytic proliferation with hemophagocytosis was also present. Since marrow aspirate or biopsy may be the first pathologic specimen examined in patients having anaplastic large-cell Ki-1 lymphoma, it is important to be able to recognize the small population of neoplastic cells, which should lead to prompt treatment or further investigations as deemed necessary.