Leukemia versus lymphoma in children: a worthless question?

Bone marrow minimal disseminated disease (MDD) and minimal residual disease (MRD) in childhood T-cell lymphoblastic lymphoma stage III, detected by flow cytometry (FC) and real-time quantitative polymerase chain reaction (RQ-PCR)

BACKGROUND

Despite overlapping features of T-cell lymphoblastic lymphoma (T-LLy) and T-cell acute lymphoblastic leukemia (T-ALL), which respond favorably to T-ALL treatment, clinical and biological differences exist. We retrospectively assessed the prevalence of submicroscopic bone marrow (BM) minimal disseminated disease (MDD) at diagnosis and the early response to treatment (minimal residual disease--MRD) and their prognostic significance in 17 children with stage III T-LLy treated according to Berlin-Frankfurt-Munster (BFM) non-Hodgkin lymphoma protocols.

PROCEDURE

Four-color flow cytometry (FC) was used for lymphoma associated immunophenotype and real-time quantitative polymerase chain reaction (RQ-PCR) for T-cell receptor (TCR beta/delta/gamma) gene rearrangements with at least 0.01% sensitivity.

RESULTS

Two markers per patient were identified in all cases using FC and in 80% using RQ-PCR. BM MDD at diagnosis of >or=0.01% was detected by FC and RQ-PCR in 88% and 80% of patients, respectively, and by at least one of the methods in all patients. A significant correlation was achieved between the methods by Pearson correlation analysis (P = 0.004). MRD levels significantly decreased to very low levels on day 33 in 9 out of 10 patients studied. The only patient that remained positive relapsed.

CONCLUSIONS

MDD was prevalent in stage III T-LLy, for which we could not prove a prognostic significance in the context of ALL-like treatment. This study shows that both FC and RQ-PCR methods are efficient for MDD and MRD analyses in T-LLy.

Non-Hodgkin's lymphoma

Pediatric lymphomas are the third most common group of malignancies in children and adolescents. Unlike lymphomas in adults, pediatric lymphomas are diffuse, aggressive neoplasms with a propensity for widespread dissemination. Intensification of conventional treatment approaches along with improvements in supportive care have resulted in dramatic improvement in event-free survival rates of close to 90% in patients with B-cell lymphomas and only slightly lower in patients with T-cell lymphomas. Lymphoid neoplasms arise because of genetic changes that result in altered growth and differential patterns of lymphoid cells. The characterization of these molecular abnormalities and an understanding of their consequences has led to new approaches to diagnosis and the detection of minimal residual disease and also provides the basis for the future development of novel treatment approaches targeted specifically to the neoplastic cells.

Therapy of Burkitt and other B-cell acute lymphoblastic leukaemia and lymphoma: experience with the LMB protocols of the SFOP (French Paediatric Oncology Society) in children and adults

Burkitt's lymphoma and L3-ALL are different forms of the same disease: B-cell disease. Therapeutic improvement has been considerable over the past 10 years. In France, four consecutive multicentre LMB studies of the SFOP greatly contributed to this improvement. An overall cure rate of 90% can now be achieved in children with a short intensive risk adapted polychemotherapy regimen based on high-dose fractionated CPM, HD MTX (3 g/m2), Ara-C in continuous infusion. For patients with ALL or with CNS involvement, the addition of CNS-directed therapy with a higher dose of MTX (8 g/m2), HD Ara-C (3 g/m2 x 4), VP 16, triple intrathecal injections and cranial irradiation greatly improved survival: 87% for ALL and 73% for patients with CNS involvement. In adults, the application of the paediatric protocol is possible with acceptable toxicity and a retrospective study of 41 cases treated according to a LMB protocol showed a cure rate of 71%. Such a regimen should now be proposed to adults and studied prospectively.

Acute lymphoblastic leukemia and non-Hodgkin's lymphoma with mediastinal mass--a study of 23 children; different disorders or different stages?

Mediastinal tumor was found in both acute lymphoblastic leukemia (ALL) and non-Hodgkin's lymphoma (NHL). Most cases showed the T-cell phenotype. We query whether these two diseases are in fact different disorders or merely different stages of the same disease. Twelve ALL patients with a mediastinal mass and eleven NHL patients with a mediastinal mass under 15 years of age were studied with respect to cytogenetics, immunophenotype, genotype and clinical features. Clonal chromosome abnormalities were found in 75% (9/12) of the ALL patients and 100% (11/11) of the NHL patients. Of the 20 patients with chromosome abnormalities, 12 (60%) had translocations involving 14q11-13 and 7q35 (8 ALL, 4 NHL). t(9;17)(q34;q23) was found only in 3 patients with NHL. All showed the T-cell phenotype except two, who had none of the chromosomal abnormalities frequently detected in T cell ALL/NHL. In T-cell patients, immunophenotypical staging of ALL showed a predominance of early and common thymocyte phenotypes while that of NHL showed a predominance of common thymocyte phenotypes. All 7 of the T-cell patients examined showed rearrangements of the T-cell receptor beta chain gene. On the other hand, two non-T-cell, non-B-cell patients showed no rearrangement. There were no apparent clinical differences between ALL and NHL patients in age (median 8.6 vs 8.9 years), sex ratio (F/M 9/3 vs 7/4) or in the rate of complete remission (90% vs 100%). Our study demonstrated no relevant clinical, prognostic, or immunophenotypic differences between ALL and NHL with mediastinal mass.(ABSTRACT TRUNCATED AT 250 WORDS)

Childhood leukaemia following the Chernobyl accident: the European Childhood Leukaemia-Lymphoma Incidence Study (ECLIS)

The objective of the European Childhood Leukaemia-Lymphoma Incidence Study (ECLIS) is to investigate trends in incidence rates of childhood leukaemia and lymphoma in Europe, in relation to the exposure to radiation which resulted from the accident at the Chernobyl nuclear power plant in April 1986. In this first report, the incidence of leukaemia in children aged 0-14 is presented from cancer registries in 20 European countries for the period 1980-1988. Risk of leukaemia in 1987-1988 (8-32 months post-accident) relative to that before 1986, is compared with estimated average dose of radiation received by the population in 30 geographic areas. The observed changes in incidence do not relate to exposure. The period of follow-up is so far rather brief, and the study is planned to continue for at least 10 years.

Non-Hodgkin's lymphomas in children. I. Patterns of disease and classification

Non-Hodgkin's lymphomas (NHL) are part of an overlapping spectrum of lympho-proliferative diseases in childhood. In the first of this 2 part series, the clinicopathological aspects of NHL in childhood are discussed. The rapid progression of disease, the high incidence of micrometastases (over 80%) at diagnosis, and the propensity of hematogenous spread to the bone marrow and the central nervous system (CNS) as well as the clinico-pathologic 'clusters' associated with particular presenting sites distinguish the pediatric forms of disease. Abdominal primary sites most frequently manifest diffuse undifferentiated (Burkitt's or non-Burkitt's) histopathology, B-cell immunophenotype, FAB-L3 cytomorphology and specific karyotypic and/or genotypic alterations of the immuno-globulin genes and the c-myc oncogene. Mediastinal presentation is associated with lymphoblastic histopathology, T-cell immunophenotype and a variety of less consistent karyotypic and genotypic aberrations. Ki-1 lymphoma, a rare subtype of large cell NHL with specific features is often of T cell origin. The requirements for diagnosis, staging and monitoring are presented in the context of the associations between clinico-pathological presentation and subsequent behavior. The most frequent sites of disease progression and relapse are involvement of the bone marrow and the CNS. For Burkitt's lymphoma there is a historic perspective and a description of particular epidemiologic, clinical, virologic, immunophenotypic and genotypic features. Cytogenetic and molecular biologic studies of genomic rearrangements are advancing the understanding of oncogenesis, clonality, lineage, and clinical behavior. The capacity to detect and amplify DNA from submicroscopic disease may contribute to prognostic stratification both at diagnosis and during subsequent monitoring.

Lymphomatous presentation of childhood acute lymphoblastic leukemia. A subgroup at high risk of early treatment failure

Multivariate analyses of the clinical course of 1537 children with acute lymphoblastic leukemia (ALL) identified a subgroup which experienced short remission duration and a high incidence of extramedullary relapse. The patients differed from other ALL patients by the presence at diagnosis of two or more of a constellation of clinical and laboratory features: organomegaly or mass disease, E-rosette positivity, hemoglobin level greater than 10 g/dl, leukocyte count greater than 50,000/microliters, male predominance, and older age. This type of presentation of ALL is referred to as the "lymphoma syndrome" (LS) since such patients exhibit a pattern of several clinical and laboratory features which were observed repeatedly but in differing combinations, and some of which clinically resemble lymphoma. A subsequent database from 2231 patients was analyzed. Patients with a mediastinal mass, massive splenomegaly, or massive adenopathy, alone or in combination, had a worse outcome when the patient also had either leukocytosis, E-rosette-positive lymphoblasts, or a normal or near normal hemoglobin (Hb) level at diagnosis. Similarly, the above three laboratory features alone or in combination did not predict less than 40% disease-free survival (DFS) unless they were accompanied by at least one of the clinical features of mass disease. When at least one clinical feature and at least one laboratory feature were present, the overall DFS was 36% 6 years after diagnosis versus 64% for all other patients. The association of these features with poor prognosis remained significant after adjusting for the level of leukocyte count at diagnosis, age at diagnosis, and sex of the patients. Patients with this recurrent syndrome of features do not represent a homogeneous biologic entity but they constitute a subgroup of patients with ALL having a high risk of treatment failure using current therapies, including failure to achieve remission, early relapse, and increased frequency of relapse in extramedullary sites. They deserve early recognition at diagnosis and selection of treatment strategies appropriate for very high risk ALL.

Malignant lymphomas in children in The Netherlands in the period 1973-1985: incidence in relation to leukemia: a report from the Dutch Childhood Leukemia Study Group

A retrospective study was done of the incidence of non-Hodgkin's lymphoma (NHL) in children in the Netherlands in the period 1973-85 in relation to that of acute lymphoblastic leukemia (ALL). Complete ascertainment of cases was most likely achieved through the network of cooperating pediatricians of the Dutch Childhood Leukemia Study Group (DCLSG). The incidence of NHL remained constant at 0.75 per 10(5) children per year; the boy/girl ratio was 2.5. In +/- 25% of cases the disease was localized at diagnosis. Of children with NHL who were not listed in the DCLSG leukemia register, 19% had greater than or equal to 25% lymphoblasts in the bone marrow at diagnosis, representing an overlap with ALL of +/- 5%. In 1% of the children with NHL an immuno-deficiency disorder preceded the diagnosis. The incidence of Hodgkin's disease (HD) was 0.3 per 10(5) children per year, with some fluctuation over time, the peak being 0.7 in 1983. The boy/girl ratio was 2.7. Age-specific incidence rates, clinical features of NHL and HD, as well as the ALL to NHL ratio corresponded with those in other European countries and for white children in the USA.