Childhood Acute Lymphoblastic Leukemia: Results of the Randomized Acute Lymphoblastic Leukemia Intercontinental-Berlin-Frankfurt-Münster 2009 Trial

PURPOSE

The International Berlin-Frankfurt-Münster (BFM) study group conducted a study on pediatric acute lymphoblastic leukemia (ALL). Minimal residual disease (MRD) was assessed using flow cytometry (FCM), and the impact of early intensification and methotrexate (MTX) dose on survival was evaluated.

PATIENTS AND METHODS

We included 6,187 patients younger than 19 years. MRD by FCM refined the risk group definition previously used in the ALL intercontinental-BFM 2002 study on the basis of age, WBC count, unfavorable genetic aberrations, and treatment response measured morphologically. Patients at intermediate risk (IR) and high risk (HR) were randomly assigned to protocol augmented protocol I phase B (IB) versus IB regimen. MTX doses of 2 versus 5 g/m² every 2 weeks, four times, were evaluated in precursor B-cell-ALL (pcB-ALL) IR.

RESULTS

The 5-year event-free survival (EFS ± SE) and overall survival (OS ± SE) rates were 75.2% ± 0.6% and 82.6% ± 0.5%, respectively. Their values in risk groups were standard risk (n = 624), 90.7% ± 1.4% and 94.7% ± 1.1%; IR (n = 4,111), 77.9% ± 0.7% and 85.7% ± 0.6%; and HR (n = 1,452), 60.8% ± 1.5% and 68.4% ± 1.4%, respectively. MRD by FCM was available in 82.6% of cases. The 5-year EFS rates in patients randomly assigned to protocol IB (n = 1,669) and augmented IB (n = 1,620) were 73.6% ± 1.2% and 72.8% ± 1.2%, respectively (P = .55), while those in patients receiving MTX doses of 2 g/m² (n = 1,056) and MTX 5 g/m² (n = 1,027) were 78.8% ± 1.4% and 78.9% ± 1.4%, respectively (P = .84).

CONCLUSION

The MRDs were successfully assessed using FCM. An MTX dose of 2 g/m² was effective in preventing relapse in non-HR pcB-ALL. Augmented IB showed no advantages over the standard IB.

Toxoplasma gondii: How fatal is it in pediatric allogeneic bone marrow transplantation setting?

Toxoplasmosis is a disease of the immunocompetent population. However, cases of toxoplasma infection associated with immunosuppression have been reported, especially the first months after transplantation. Limited data are available about toxoplasma infection, occurring even many months post-transplant in pediatric patients with nonmalignant and malignant diseases. We report the cases of three patients with early and late disseminated toxoplasmosis and review the literature.

BCL2L12 improves risk stratification and prediction of BFM-chemotherapy response in childhood acute lymphoblastic leukemia

Background Risk-adjusted treatment has led to outstanding improvements of the remission and survival rates of childhood acute lymphoblastic leukemia (ALL). Nevertheless, overtreatment-related toxicity and resistance to therapy have not been fully prevented. In the present study, we evaluated for the first time the clinical impact of the apoptosis-related BCL2L12 gene in prognosis and risk stratification of BFM-treated childhood ALL. Methods Bone marrow specimens were obtained from childhood ALL patients upon disease diagnosis and the end-of-induction (EoI; day 33) of the BFM protocol, as well as from control children. Following total RNA extraction and reverse transcription, BCL2L12 expression levels were determined by qPCR. Patients' cytogenetics, immunophenotyping and minimal residual disease (MRD) evaluation were performed according to the international guidelines. Results BCL2L12 expression was significantly increased in childhood ALL and correlated with higher BCL2/BAX expression ratio and favorable disease markers. More importantly, BCL2L12 expression was associated with disease remission, while the reduced BCL2L12 expression was able to predict patients' poor response to BFM therapy, in terms of M2-M3 response and MRD≥0.1% on day 15. The survival analysis confirmed the significantly higher risk of the BFM-treated patients underexpressing BCL2L12 at disease diagnosis for early relapse and worse survival. Lastly, evaluation of BCL2L12 expression clearly strengthened the prognostic value of the established disease prognostic markers, leading to superior prediction of patients' outcome and improved specificity of BFM risk stratification. Conclusions The expression levels of the apoptosis-related BCL2L12 predict response to treatment and survival outcome of childhood ALL patients receiving BFM chemotherapy.

A prospective study on the epidemiology and clinical significance of viral respiratory infections among pediatric oncology patients

Respiratory infections in oncology are both common and potentially severe. However, there is still a gap in the literature, regarding the epidemiology of viral respiratory infections in children with cancer. We prospectively enrolled 224 patients, from September 2012 to August 2015. The cohort included children with hematologic or solid malignancies receiving chemotherapy, or undergoing hemopoietic stem cell transplantation, outpatients/inpatients exhibiting signs/symptoms of febrile/afebrile upper/lower respiratory infection. Viral infection was diagnosed by detection of ≥1 viruses from a sample at time of enrollment, using the CLART^® PneumoVir kit (GENOMICA, Spain). Α detailed questionnaire including demographics and medical history was also completed. Samples were processed in batches, results were communicated as soon as they became available. Children recruited in whom no virus was detected composed the no virus detected group. Viral prevalence was 38.4% in children presenting with respiratory illness. A single virus was found in 30.4%, with RSV being the most frequent. Viral coinfections were detected in 8%. Children with viral infection were more likely to be febrile upon enrollment and to present with lower respiratory signs/symptoms. They had longer duration of illness and they were more likely to receive antibiotics/antifungals. Only 22% of children with influenza received oseltamivir. Mortality was low (2.7%), however, pediatric intensive care unit (PICU) admission and death were correlated with virus detection. In our study mortality was low and PICU admission was related to virus identification. Further research is needed to clarify whether antibiotics in virus-proven infection are of value and underline the importance of oseltamivir's timely administration in influenza.

Immune response to influenza vaccination in children with cancer

The aim of this study was to evaluate the ability of influenza immunization to evoke a protective immune response among children with cancer. We evaluated 75 children with cancer who received influenza vaccination. Hemagglutination Inhibition Antibody titers were determined before and after vaccination. The protective rates after vaccination were 79% for H1N1, 75% for H3N2 and 59% for influenza B virus whereas the seroconversion rates were 54%, 44% and 43% respectively. The differences pre- and post-vaccination were significant regardless the method which was used: seroprotection changes, seroconversion and geometric mean titers analyses. Variables such as the pre-vaccination antibody titers, the time when the responses were measured after the vaccination, the age and the type of malignancy as well as the absolute lymphocyte count were found to be correlated with the immune response but the findings were different for each vaccine subunit. In conclusion, influenza vaccination provides protection in a remarkable proportion of pediatric cancer patients whereas this protection is more obvious against H1N1 and H3N2 compared to influenza B. The immune response after vaccination is significant and seems to be influenced by a variety of factors.

Optic pathway glioma in children: 10 years of experience in a single institution

Optic pathway glioma (OPG) is a rare brain tumor that occurs more commonly during early childhood and is frequently associated with neurofibromatosis type 1 (NF1). In this study, our aim was to describe the characteristics, management, and outcome of patients with OPG. We retrospectively analyzed the clinical charts of all children diagnosed with OPG at our institution from 2003 to 2013. Twenty children (11 boys and 9 girls, median age: 5 and 3/12 years; NF1: 15/20) were diagnosed with OPG. The diagnosis was based on magnetic resonance imaging (MRI) findings. A biopsy was useful in 3 patients. The main reason for seeking medical advice was decreased vision (7/20 patients), whereas in 10/20 patients, the diagnosis was established during the routine follow-up for their NF1. Fifteen patients demonstrated MRI findings of optic nerve involvement and/or chiasmal tumor, whereas in 5 children, postchiasmal structures were also involved. Sixteen patients (16/20) received carboplatin-based regimens, whereas 4/20 patients were only under close observation. Six patients showed deterioration of visual acuity and/or imaging findings at the end of treatment and/or during their follow-up. Three of them (3/6) underwent tumor resection, whereas 1 (1/6) received radiation treatment. None of our patients had total blindness from both eyes. Half of our patients were diagnosed during follow-up for their NF1, the incidence of which was high in our group. Our data suggest that chemotherapy helps in the preservation of vision in the majority of children.

Prayer and blessings focused for healing is the most popular complementary intervention in a paediatric oncology unit in Greece

PURPOSE

Increasing numbers of children with cancer are using complementary and alternative medicine (CAM) therapies. Our aim was to estimate the rate of use, the beliefs of users and non-users and factors related with the use of CAM among Greek families.

METHODS

A self-reported questionnaire was given to parents of 184 children with cancer. We assessed the rate of use, types of CAM therapies and factors potentially associated with the use of CAM.

RESULTS

Based on the 110 questionnaires which were completed (59.8% of the families), 23 families (21%) had used at least one complementary treatment. The most common forms were: spiritual healing/prayer/blessings 18/23 (78%), art therapies 4, dietary supplements 3, massage 3, homeopathy 2, and herbals 2. The reasons given for use included: making the child stronger 17/23 (48%, hope of stopping the cancerous process 11/23 (49%), and coping with side effects 6/23 (26%). Among the reasons given by the parents for not using CAM therapies the most common (84%) was the effective conventional treatment and, therefore, there was no need for CAM use. Another 24% reported that were unaware of these "alternative" and "complementary" therapies and a further 7% had considered using them but finally they didn't. In bivariate analysis, the use of CAM was not associated either with age, sex, nationality, education or occupation of the parents at the time of the survey, or with diagnosis, mode of therapy or age of the child at diagnosis.

CONCLUSIONS

The use of CAM therapies by Greek families for their children with cancer does not appear to be very popular, although the experiences of those who did use them were generally positive.

Nephrotic syndrome and Hodgkin lymphoma in children. Report of two cases

BACKGROUND

The association of nephrotic syndrome (NS) and Hodgkin's lymphoma (HL), although rare, is well recognised. In the majority of cases of HL, minimal change NS is detected.

DESCRIPTION OF CASES

This report presents the occurrence of NS in two children with HL. In the first case, NS preceded the diagnosis of lymphoma by 3 months, while in the other child, the two disorders occurred simultaneously. In both cases, clinical manifestations and laboratory parameters (proteinuria) of NS resolved after effective treatment for active HL.

CONCLUSION

Prolonged proteinuria may be a paraneoplastic syndrome and HL should be considered in the diagnosis as it is crucial for the management of both entities.

A novel karyotype in acute myeloid leukemia with basophilia

Acute basophilic leukemia is a distinct entity of Acute Myeloid Leukemia (AML) with primary differentiation to basophils. Increased basophil count has been described in AML cases with translocation t(6;9)(p23;q34) or other chromosomal abnormalities. We describe a 15-year old female teenager with AML and excess peripheral blood and bone marrow basophils. Her white blood cell count at diagnosis was 15.4 G/L with 53% basophils and 17% blasts. The bone marrow cytogenetics analysis did not reveal any of the usual abnormalities. The karyotype showed two closely related leukemic clones: the first (16 metaphases), with a total of 48 chromosomes, had an extra chromosome 8 with deletion of the long arm and an additional 21 (48,XX, +del(8)(q24.2q24.3), t21[16]), while the second clone (2 metaphases), with a total of 47 chromosomes, did not contain the extra 21 chromosome (47, sl, -21[2]). In summary, in this case of AML-M2 with excess basophils, there is a novel chromosomal abnormality, not previously reported in this entity.

Differences between younger and older patients with childhood hodgkin lymphoma

From 1979 to 2006, 74 children with Hodgkin's lymphoma were treated at our center. Among them, 15 (14 boys and 1 girl) and 59 (33 boys and 26 girls) patients were younger and older than 8 years, respectively. Six (40%) children among younger patients and 26 (44%) among older patients had advanced stage disease. We detected 3 (20%) relapses among younger patients and 5 (8.5%) among the older patients. All of younger patients are alive whereas three of the older patients have died. Second malignancy developed in one and three children among younger and older patients, respectively. The only difference that was detected concerning the age was a male predominance among the younger patients.

Compliance with immunization against H1N1 influenza virus among children with cancer

In this report, we describe the experience with immunization against pandemic influenza A H1N1 in children with cancer treated at a pediatric oncology department during the pandemic season (2009). According to the guidelines, vaccination of all children with cancer receiving chemotherapy as well as those who had completed treatment was scheduled. Among the 140 children who were eligible for immunization, 122 were immunized, achieving a compliance rate of 87% despite negative publicity and low vaccine uptake in the general population. The vaccine was tolerated and none of the vaccinated children developed influenza. It is concluded that high immunization rates can be achieved among pediatric oncology patients.

Successful treatment with minimal chemotherapy followed by low-dose involved field radiotherapy in children with Hodgkin's disease: A 20-year experience in a single institution in Greece

10052

Background: The vast majority of children with Hodgkin's disease (HD) nowadays have an excellent chance of definite cure. The high curative rates as well as the prevention of late effects have to be among aims when managing children with HD. The purpose of our retrospective study was to report the outcome and prognostic factors of patients (pts) less than 15 years of age with HD treated with chemotherapy (CT) followed by low dose radiation from 1987 to 2006. Methods: We studied 58 children analyzing the following data: age, sex, stage, histology, therapy correlating these with the outcome of pts. Among 35 boys and 23 girls, age at diagnosis 4.5 - 15 years (median 12), all aged 7 years or less were boys (8/58). Nodurar sclerosis was the predominant histology subtype (69%) and 45% had advanced disease (stages III or IV). According the study period pts with early stage received 4 cycles of ABVD or VBVP and those with advanced stage disease alternating 3 cycles of MOPP/ABVD or 2 of MOPP/ABVP for stage III and alternating 3 cycles of MOPP/ABVD or 2 OPPA plus 4 COPP for stage IV. All pts had a good response (more than a 70% reduction) after initial CT and received 20 Gy of RT to initially involved fields. Results: Complete remission (CR) was achieved in all patients. Chemo- and radio-therapy were well tolerated. Fifty-three pts (DFS: 91.4%) live in their first complete remission. In 5 pts (8.6 %) relapse occurred, 20 -65 months from dx (median 25 mo). All received salvage treatment in combination with high dose CT and autologous stem-cell transplantation (SCT). Of the 5 relapsed all live 21 - 207 months (median 75 mo) from the dx of relapse and 41 - 232 mo (median 99) from the dx of disease. Second (thyroid cancer) plus third malignancy in one (osteosarcoma) was detected in 3 pts and all are alive. Finally for our group the overall survival is 100% and all children are alive 25 - 264 mo from dx (median 145 mo) and the event free survival is 86.2% (50/58). No factors related to the outcome were detected. Conclusions: In conclusion combined-modality therapy remains the standard of care for children with HD. However, there may be a significant number who can be cured with chemotherapy alone. At this moment the main question is: who can be cured without RT?

No significant financial relationships to disclose.

Long-term effects of chemotherapy for acute lymphoblastic leukemia on the medial olivocochlear bundle: effects of different cumulative doses of gentamicin

OBJECTIVE

The treatment of acute lymphoblastic leukemia (ALL) often combines a neurotoxic chemotherapeutic protocol such as Berlin-Frankfurt-Munster-95 (BFM-95) with gentamicin, an antibiotic known to have an early and quickly reversed impact on olivocochlear reflex in animal studies. This study investigates whether this combination has any long-term side effects on the medial olivocochlear bundle (MOCB).

METHODS

In all 47 children of the study suppression of distortion product otoacoustic emissions (DPOAEs) by contralateral application of white noise (WN) was used to assess the function of the MOCB. The population was divided into three groups depending on the time interval between the end of therapy and examination. The group examined shortly after chemotherapy included 12 children who had received low gentamicin doses (less than 13 days). The group evaluated 2 years after therapy involved another 12 children who had required medium gentamicin doses (more than 13, less than 23 days). The group examined 3 years after therapy included a subgroup of 12 children to whom low gentamicin doses were infused and another 11 children with high gentamicin doses (more than 23 days).

RESULTS

Three years after therapy the olivocochlear reflex was efficiently produced in both subgroups of low and high gentamicin doses. Two years after therapy, contralateral WN induced increase of DPOAEs at 4 of the 12 examined frequencies. Shortly after therapy, WN increased, instead of suppressing, DPOAEs at five frequencies.

CONCLUSION

This abnormal result of contralateral noise application perceived as impaired cochlear efferent innervation may indicate that ALL-BFM-95 exerts a toxic effect on the MOCB, which is slowly reversed within the first 3 years after chemotherapy and does not seem to be affected in the long term by different cumulative doses of gentamicin.

Negative gallium-67 citrate and positive positron emission tomography/computed tomography spleen scans, in Hodgkin's stage IV lymphoma

An 18-year-old male patient with Hodgkin's lymphoma stage IVB (HL-IVB), is presented. On a follow-up examination a splenic ultrasound scan showed the presence of multiple intense nodules. The gallium-67 citrate, single photon emission tomography scan was negative, while positron emission tomography/computerized tomography (PET/CT) scan with fluoro-18-fluordeoxyglucose was strongly positive. Massive infiltration of the spleen by HL-IVB tissue was confirmed by pathology after splenectomy. Two successive PET/CT studies for follow-up purposes three and twelve months after completion of chemotherapy, were normal.

Optic pathway glioma associated with orbital rhabdomyosarcoma and bilateral optic nerve sheath dural ectasia in a child with neurofibromatosis-1

Neurofibromatosis-1 (NF-1) is a multisystem disorder presenting with a variety of clinical and imaging manifestations. Neural and non-neural tumours, and unusual benign miscellaneous conditions, separately or combined, are encountered in variable locations. We present a 2(1/2)-year-old boy with NF-1 who demonstrated coexisting optic pathway glioma with involvement of the chiasm and optic nerve, orbital alveolar rhabdomyosarcoma and bilateral optic nerve sheath dural ectasia.

Hypermethylation of CpG islands in the promoter region of the p15INK4B gene in childhood acute leukaemia

It has been reported that the cyclin-dependent kinase inhibitor (CDKI) gene p15INK4B is frequently inactivated by genetic alterations and may be responsible for various malignant tumours. Another way of inactivation of this CDKI is by hypermethylation of 5'CpG islands in the promoter region of the p15INK4B gene and this inactivation seems to be a frequent event in various haematological malignancies. In the present study, we investigated the methylation status of the p151NK4B gene to clarify its role in the pathogenesis of childhood acute myeloid (AML) and acute lymphoblastic leukaemia (ALL). The study included 23 cases of B-cell origin ALL, 13 cases of T-cell origin ALL, 32 cases of AML, and 10 apparently healthy controls. Hypermethylation was studied by methylation-specific polymerase chain reaction. Hypermethylation of the p15INK4B gene was more frequent in cases with T-cell origin ALL (46.2%), but similar among children with B-cell origin ALL (13.0%) and AML (18.8%). Hypermethylation of p15INK4B may be involved in the pathogenesis of T-cell origin ALL, but not in that of AML or B-cell origin ALL.

Insulin-like growth factor-I and binding protein-3 in relation to childhood leukaemia

The aetiology of most cases of childhood leukaemia remains unknown, but several studies have indicated that increased birthweight and height are risk factors for the disease. Since insulin-like growth factor-I (IGF-I) mediates the effect of growth hormone and has been positively associated with prostate cancer, we have evaluated the role of this hormone and its principal binding protein, IGFBP-3, in the aetiology of childhood leukaemia. Incident cases of childhood leukaemia from those recorded by a national network of childhood oncologists were enrolled in our study. Controls were children hospitalised for acute conditions of no more than moderate severity with matching for gender, age and maternal place of residence. Blood measurements of IGF-I and IGFBP-3 were undertaken using commercially available radioimmunoassays. Serum IGF-I values decreased by about 1.7% per month, and the rate of decline was higher, though not significantly so, among cases (2.1% per month) than among controls (1.4%). There was no significant association between IGF-I and the likelihood of childhood leukaemia, but an increment of 1 microg/ml of IGFBP-3 was associated with a substantial and statistically significant reduction of childhood leukaemia by 28% (95% confidence interval 7% to 45%). Because IGFBP-3 is essentially a binding protein, we interpret our findings as indicating that bioavailable IGF-I may play an important role in the aetiology of childhood leukaemia. The much smaller quantities and the inherent instability of IGF-I in the blood in comparison to those of IGFBP-3 are likely to hinder documentation of an underlying positive association of IGF-I with the disease.

Reported influenza in pregnancy and childhood tumour

The present study was conducted to test the hypothesis that exposure to influenza in pregnancy increases the risk of tumour of certain type in childhood. Children ages 17 years or less diagnosed in Greece with brain tumours or neuroblastomas from 1982 to 1993 (n = 94) were contrasted to 210 controls selected from the same hospitals. Mothers of these children were interviewed about a variety of possible etiologic factors. The prevalence of influenza in Greece for each year during the period 1984-1992 was also compared with the number of children born during the same year who subsequently developed brain tumour or neuroblastoma. The results indicate a significant association between influenza in pregnant women and occurrence of tumour in index child (OR: 3.15, 95% CI: 1.13-8.77). These results persisted when adjustment for potential confounding factors was made. The findings should be interpreted cautiously because of lack of serologic documentation of information about infection obtained in interviews. A positive correlation (r = 0.74) of the number of tumour births by year of birth with the prevalence of influenza during the same year was also noted. This exploratory study is one of the few case-control studies of the epidemiology of childhood tumours in children, and the results suggest directions for future epidemiologic studies in this relatively uncharted field.

Electrical power lines and childhood leukemia: a study from Greece

Residential proximity to electrical power lines of different voltage in relation to childhood leukemia was investigated through a case-control study undertaken in Greece during 1993-1994. The study comprised 117 incident cases of childhood leukemia and 202 age-, gender- and place-of-residence-matched controls. Four measures of exposure to magnetic fields were developed, using data provided by the Public Power Corporation of Greece: Voltage (V) divided by the distance (d), V/d2, V/d3 and an adaptation of the Wertheimer-Leeper code. Conditional-logistic-regression modeling was used to adjust for potential confounding influences of 18 variables. No significant trends of childhood leukemia risk with increasing exposure levels were noted, nor were there statistically significant elevations of disease risk at the higher exposure levels in each measure of exposure. These results do not support a causal link between residential proximity to electrical high-voltage wires and childhood leukemia risk, but in themselves do not refute a weak empirical association.

Aggregation of childhood leukemia in geographic areas of Greece

A total of 872 children aged up to 14 years, who were diagnosed with leukemia in Greece during the decade 1980-89, were allocated by place of residence to the 601 administrative districts of the country. Evaluation of spatial clustering was done using the Potthoff-Whittinghill method, which validly assesses heterogeneity of leukemia risk among districts with variable expected numbers of cases. There was highly significant evidence for spatial clustering occurring particularly among children living in urban and, to a lesser extent, semi-urban areas. The evidence was stronger for children younger than 10 years old, applied also to children in different five-year age groups, and persisted when cases of acute lymphoblastic leukemia were analyzed separately. These findings provide support to the hypothesis that localized environmental exposures could contribute to the etiology of childhood leukemia, but they cannot distinguish between exposures of physical or chemical nature, nor can they exclude socially conditioned patterns of exposure to infectious agents.

The risk profile of childhood leukaemia in Greece: a nationwide case-control study

The risk profile of childhood leukaemia in Greece was studied through a case-control investigation that included all 153 incident cases of the disease, ascertained throughout the country during 1993 and 1994, and two hospital controls for every case matched for gender, age and place of residence. The data were analysed using conditional logistic regression and the associations are expressed in terms of adjusted odds ratios (OR) and their 95% confidence intervals. Cases were born to mothers of a higher standard education, the OR for an increment of four schooling years being 1.48 (1.17-1.87) and had higher birth weight, the OR for an increment of 500g being 1.36 (1.04-1.77). Pet ownership and birth after a pregnancy with anaemia were associated with increased risk, the ORs being 2.18 (1.14-4.16) and 2.60 (1.39-4.86) respectively. From the frequency analyses, indicative inverse associations were found with birth order, household crowding and previous hospitalization with allergic diseases, whereas indicative positive associations were found with diabetes mellitus during pregnancy and with neonatal jaundice. Substantial or significant elevations were not found with respect to maternal smoking and coffee drinking during pregnancy, diagnostic radiography and ultrasonographic examinations or blood transfusions. A significant inverse association with maternal consumption of alcohol could be due to multiple comparisons, but a detrimental effect can probably be excluded. A non-significant positive association with total shots of viral vaccinations and a weak non-significant inverse association with breast feeding were also found. We interpret the findings of this study as being compatible with acute childhood leukaemia being linked with delayed development of herd immunity to fairly common infectious agents, in conjunction with accelerated perinatal and early post-natal growth.

Infant leukaemia after in utero exposure to radiation from Chernobyl

There has been no documented increase in childhood leukaemia following the Chernobyl accident. However, different forms of childhood leukaemia may not be equally susceptible to radiation carcinogenesis. Infant leukaemia is a distinct form associated with a specific genetic abnormality. Outside the former Soviet Union, contamination resulting from the Chernobyl accident has been highest in Greece and Austria and high also in the Scandinavian countries. All childhood leukaemia cases diagnosed throughout Greece since 1 January 1980 have been recorded. Here we report that infants exposed in utero to ionizing radiation from the Chernobyl accident had 2.6 times the incidence of leukaemia compared to unexposed children (95% confidence interval, 1.4 to 5.1; P approximately 0.003), and those born to mothers residing in regions with high radioactive fallout were at higher risk of developing infant leukaemia. No significant difference in leukaemia incidence was found among children aged 12 to 47 months. Preconceptional irradiation had no demonstrable effect on leukaemia risk at any of the studied age groups.

Space-time clustering of childhood leukaemia in Greece: evidence supporting a viral aetiology

The method introduced by Knox for evaluation of space-time clustering has been applied to 872 cases of childhood (0-14 year old) leukaemia diagnosed in Greece over the 10 year period 1980-89. Greek towns are characterised by substantial population mixing due to internal migration, whereas there is relative isolation in mountainous rural areas. Predetermined space (5 km) and time (1 year) limits were used on the basis of previous reports in order to define the clustering cell. There is highly significant evidence for clustering of childhood leukaemia in Greece as a whole, the observed number of pairs that are close in both spaces and time exceeding the expected number by 5.2% (P = 0.004). The excess is particularly evident for leukaemia cases in 0 to 4-year-old children, among whom the observed number of pairs that are close in both space and time exceeded the expected number by 9.4% (P = 0.004). There is no evidence of space-time clustering for leukaemia cases older than 5 years. The overall pattern is descriptively similar in urban and semiurban areas and is especially marked for acute lymphoblastic leukaemia at the childhood peak ages (2-4 years) with an excess of 19% (P = 0.0006). In the rural population there is evidence for clustering of cases belonging to older and broader age groups, a phenomenon compatible with a delay in the development of herd immunity against putative infectious aetiological agents. The findings of the present study provide support for the hypothesis that a substantial proportion of cases of childhood leukaemia may arise as a rare sequel to exposure to an agent or agents, most probably viral in nature.

Survival from childhood leukemia depending on socioeconomic status in Athens

One hundred and twenty children first diagnosed as having acute leukemia between 1988 and 1992 in Athens, Greece, were followed until May 15, 1993. The socioeconomic status of the children's families was assessed by means of paternal occupation, paternal schooling, maternal schooling, ownership of a car, ability to choose a private medical facility and freedom in the choice of the attending physician. The analysis was done by proportional-hazards modelling, controlling for age and gender. All six socioeconomic indicators, alternatively evaluated, showed that fatality rates were higher in the lower socioeconomic groups, although nominal statistical significance was reached for only one of them. With respect to family ownership of a private car, the fatality rate ratio between children of families who own a car and children of families who do not was 0.29 with a 95% confidence interval of 0.13-0.62 (p = 0.002). These results suggest that in Greece, socially disadvantaged children have a less favorable survival from childhood leukemia.

Establishment and characterization of a hepatoblastoma cell-line from a patient with secondary acute myeloid-leukemia

A girl who had been treated, apparently successfully, with surgery and chemotherapy for a hepatoblastoma, fell ill two years later with what was diagnosed as an AMF M(4). A cell line was established from her peripheral blood. This cell line had epithelial morphology and grew both in suspension culture and as a monolayer. The cells were positive for epithelial surface markers, including the liver-specific alpha-fetoprotein, but not for leukocyte markers. The cell-line's karyotype was markedly abnormal. It did not have any specific aneuploidies or any other aberrations characteristic of leukemias; instead it had gains of 2q and chromosome 20, the most common cytogenetic changes in hepatoblastoma. It is most likely that the patient had a relapse of hepatoblastoma with massive seeding of the blood leading to a leukemia-like picture without, of course, excluding other possibilities.

Trends and geographical distribution of childhood leukemia in Greece in relation to the Chernobyl accident

Parts of Greece have been exposed to fallout radiation from the Chernobyl accident as much as any of the countries boardering with the former Soviet Union, because of the direction of the prevailing winds after the accident. Although fallout radiation did not reach levels expected to be associated with measurable effects, there is widespread concern in Greece that the incidence of childhood leukemia may be rising in the more heavily affected parts of Greece. Patient discharge data from all Greek hospitals treating childhood leukemia were used to calculate the annual incidence of the disease from January 1980 to June 1986 (preaccident period), from July 1986 to June 1988 (immediate postaccident period) and from July 1988 to June 1991 ("relevant" post-accident period, that accommodates the presumed latent period of the disease). Fallout radiation measurements (in Bq/kg Cs-137) were used to create 17 regions of similar (within regions) but highly variable (between regions) levels of fallout deposition. Background radiation (in Bq/kg Ra-226) and annual incidence of childhood leukemia by region were also estimated. There was no evidence of increased incidence of childhood leukemia during the immediate or the "relevant" post-Chernobyl period in any part of the country. Furthermore, regression analyses did not show any significant or suggestive association of childhood leukemia by region with either background or fallout radiation. These results indicate that the Chernobyl accident did not affect noticeably the incidence of childhood leukemia in Greece during the five-year post accident period.

Constitutive heterochromatin polymorphisms in children with acute lymphoblastic leukemia

The C-band heterochromatin polymorphisms of chromosomes 1, 9, and 16 were studied on peripheral lymphocytes of 67 children with acute lymphoblastic leukemia (ALL) and 50 control individuals. A statistically significant difference between patients and controls was found for large heterochromatin regions (level 3) of chromosomes 1 and 9 (P < 0.001) and for small heterochromatin regions (level 1) of chromosome 16 (P < 0.001). The patients also showed a significant increase in chromosomes 1 and 9 heteromorphism with respect to controls (P < 0.001).