Search

The 5-year overall survival of children and adolescents with osteosarcoma has been in plateau during the last 30 years. The present systematic review (1976-2023) and meta-analysis aimed to explore factors implicated in the prognosis of children and young adults with high-grade osteosarcoma. Original studies including patients ≤30 years and the Nationwide Registry for Childhood Hematological Malignancies and Solid Tumors (NARECHEM-ST) data (2010-2021) referred to children ≤14 years were analysed. Individual participant data (IPD) and summary estimates were used to assess the n-year survival rates, as well as the association of risk factors with overall survival (OS) and event-free survival (EFS). IPD and the n-year survival rates were pooled using Kaplan-Meier and Cox regression models, and random effects models, respectively. Data from 8412 patients, including 46 publications, NARECHEM-ST data, and 277 IPD from 10 studies were analysed. The summary 5-year OS rate was 64% [95% confidence interval (95%CI): 62%-66%, 37 studies, 6661 patients] and the EFS was 52% (95%CI: 49%-56%, 30 studies, 5010 patients). The survival rates generally differed in the pre-specified subgroups. Limb-salvage surgery showed a higher 5-year OS rate (69%) versus amputation (47%). Good responders had higher OS rates at 3 years (94%) and 5 years (81%), compared to poor responders at 3 years (66%), and 5 years (56%). Patients with metastatic disease had a higher risk of death [Hazard Ratio (HR): 3.60, 95%CI: 2.52, 5.15, 11 studies]. Sex did not have an impact on EFS (HR females/males : 0.90, 95%CI: 0.54, 1.48, 3 studies), whereas age>18 years seems to adversely affect EFS (HR 18+/<10 years : 1.36, 95%CI: 1.09, 1.86, 3 studies). Our results summarize the collective experience on prognostic factors of high-grade osteosarcoma among children and young adults. Poor response to neoadjuvant chemotherapy and metastatic disease at diagnosis were confirmed as primary risk factors of poor outcome. International collaboration of osteosarcoma study groups is essential to improve survival., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

We assessed event-free (EFS) and overall (OS) survival in 676 incident cases of childhood Hodgkin (HL) and non-Hodgkin (NHL) lymphoma actively registered in Greece (1996-2019). HL-OS 5-year was 96% and NHL-OS 5-year 85%, whereas HL-EFS 5-year was 86% and NHL-EFS 5-year was 81%, notably similar to the respective OS rates (HL: 95%, NHL: 85%) in developed countries. For HL, older age at diagnosis, high maternal education and close proximity to treatment centers were linked to remarkably favorable outcomes. By contrast, stage IV patients showed worse OS and EFS. HL patients with low levels of hemoglobin were associated with worse EFS (hazard ratio: 2.81, 95% confidence intervals: 1.09-7.22). OS (76%) and EFS (73%) were poor among high-risk NHL patients and those with increased LDH (71%). The identified predictors of poor disease outcome point to the need for intensification of individualized treatments. Ongoing clinical cancer registration entailing clinical components could contribute to use of state-of-the-art treatments.

Background: The childhood peak of brain tumors suggests that early-life exposures might have a role in their etiology. Hence, we examined in the Greek National Registry for Childhood Hematological Malignancies and Solid tumors (NARECHEM-ST) whether perinatal and early-life risk factors influence the risk of childhood brain tumors., Methods: In a nationwide case-control study, we included 203 cases (0-14 years) with a diagnosis of brain tumor in NARECHEM-ST (2010-2016) and 406 age-, sex-, and center-matched hospital controls. Information was collected via interviews with the guardians and we analyzed the variables of interest in multivariable conditional logistic regression models., Results: Instrument-assisted delivery was associated with higher (OR: 7.82, 95%CI: 2.18-28.03), whereas caesarean delivery with lower (OR: 0.67, 95%CI: 0.45-0.99) risk of childhood brain tumors, as compared to spontaneous vaginal delivery. Maternal alcohol consumption during pregnancy (OR: 2.35, 95%CI: 1.45-3.81) and history of living in a farm (OR: 4.98, 2.40-10.32) increased the odds of childhood brain tumors. Conversely, higher birth order was associated with lower risk (OR for 2nd vs. 1st child: 0.60, 95%CI: 0.40-0.89 and OR for 3 rd vs. 1 st : 0.34, 95%CI: 0.18-0.63). Birth weight, gestational age, parental age, history of infertility, smoking during pregnancy, allergic diseases, and maternal diseases during pregnancy showed no significant associations., Conclusions: Perinatal and early-life risk factors, and specifically indicators of brain trauma, exposure to toxic agents and immune system maturation, might be involved in the pathogenesis of childhood brain tumors. Larger studies should aim to replicate our findings and examine associations with tumor subtypes., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

The aim of the present nationwide Greek study is to assess whether survival from acute lymphoblastic leukemia (ALL) and acute myeloid leukemia (AML) is modified by socioeconomic status (SES) and area remoteness. Detailed precoded information derived from a personal interview conducted by specially trained health personnel with the child guardians was available for 883 ALL and 111 AML incident childhood cases registered in the Nationwide Registry for Childhood Hematological Malignancies during the period 1996-2010. Parental socioprofessional category was recorded on the basis of ISCO68 and ISCO88 codes; the exact traveling distance between residence and the treating hospital was ad hoc calculated. Multivariate Cox's proportional hazards models were applied to examine the mutually adjusted associations between survival and potential predictors. Children from a lower parental socioprofessional category experienced 40% worse survival (P=0.02) independent of age, sex, and ALL subtype, whereas those whose parents were married had better outcomes (rate ratio: 0.47, P=0.01). Urbanization of residence at diagnosis or 'residence to treating hospital' distance was not nominally associated with survival from ALL. By contrast, no noteworthy associations implicating SES were found for AML survival, probably because of the burden of the disease and small numbers. Lower SES indicators and a single-parenthood family milieu seem to be independently associated with unfavorable outcomes from childhood ALL. Area remoteness might not be a significant outcome predictor during recent years, following considerable improvements in the motorway infrastructures and care delivery patterns. This study may provide a valuable snapshot capturing the impact of socioeconomic covariates before the burst of the Greek financial crisis.

Background: Several reports point to inverse associations between allergies and ALL; yet, no study has explored this link using both self-reported-data on allergic history and biomarkers of atopic sensitization., Methods: Clinical information for the variables of interest was available for 252 out of 292 cases of childhood (0-14 years) ALL, newly diagnosed across Greece over a 4.5 year period as well as for 294 hospital controls. Allergen-specific-IgEs, as markers of allergic predisposition, against 24 most prevalent respiratory and food allergens, were determined, using an enzyme immunoassay procedure for 199 children with ALL and 113 controls. Cases were compared with controls through frequency distributions and unconditional multiple logistic regression models to estimate odds ratios (ORs) and 95% confidence-intervals (CIs) regarding associations of allergy with childhood ALL., Results: Self-reported-allergic history overall (OR: 0.49, 95% CI: 0.34-0.72) and practically each one of its main components (respiratory, food, any other clinical allergy) were strongly and inversely associated with ALL. Likewise, the serum IgE inverse association was of the same magnitude (OR: 0.43, 95% CI: 0.22-0.84) mainly contributed by food IgE (OR: 0.39, 95% CI: 0.18-0.83)., Conclusion: Beyond the already established inverse association of allergic history with childhood ALL, a same magnitude association is evident when serologic markers of allergic predisposition are used as an alternative measure of allergy. Further research with more appropriate study designs is needed to better understand possible associations between prior allergy and childhood ALL risk., (Copyright © 2012 Elsevier Ltd. All rights reserved.)

Purpose: There is a paucity of findings concerning the role of diet in childhood leukemogenesis, whereas the results are equivocal and the studies heterogeneous with regard to food items examined. This case-control study investigates the association of childhood leukemia with food groups, macronutrient consumption, total energy intake and adherence to Mediterranean diet among children aged 5-14 years in Greece., Methods: A total of 139 consecutive, incident leukemia cases out of which 121 were acute lymphoblastic leukemia were derived from the Nationwide Registry for Childhood Hematological Malignancies along with one : one age- and gender-matched hospital controls. Information on socio-demographic, maternal and child variables and dietary habits was obtained through in-person interviews with the guardians/children. Multiple logistic regression was performed with adjustment for birth weight and possible confounding variables., Results: Higher consumption of added lipids was associated with an increased risk of childhood leukemia, whereas consumption of milk and dairy products with reduced risk. From the macronutrient analysis, a borderline trend linking high protein intake with reduced childhood leukemia risk was observed., Conclusion: Consumption of milk and dairy products in the first year of life may protect against childhood leukemia possibly through vitamin D actions, while added lipids may increase the risk through various mechanisms. These results offer a holistic evaluation of children's nutrition and suggest that dietary habits in the early years of life may contribute to the prevention of childhood leukemia.

An increase of the prevalence of childhood allergic diseases and the incidence of childhood Hodgkin's (HL) and non-Hodgkin's lymphoma (NHL) were reported in the late 20th century. Among adults, several studies point to an inverse association with lymphoma; it remains to be confirmed whether allergy is also related to childhood lymphomas and whether the association, if any, is of an aetiologic nature. Between 1996 and 2008, 277 children (aged 0-14 years) with HL (N = 111) or NHL (N = 166) were enrolled in Nationwide Registry for Childhood Hematological Malignancies (NARECHEM), a Greek hospital-based-registry of childhood hematological malignancies. Hospital controls were individually matched to cases on age and sex. Multivariate conditional logistic regression was used to estimate odds ratios (ORs) with 95%confidence intervals (CIs) for associations of allergic diseases and other covariates with childhood HL or NHL risk. Subsequently, we combined our results with those of a French case-control study in a meta-analysis amounting to a total of 330 NHL cases/1478 controls and 239 HL cases/959 controls. After controlling for sociodemographic, perinatal and environmental factors, childhood NHL was less prevalent among children with allergy-associated symptoms overall (OR:0.50, 95%CI:0.27-0.92) or a history of asthma (OR:0.43, 95%CI:0.21-0.88). By contrast, allergy did not seem to be associated with childhood HL risk, although statistical power was limited. Fewer seaside holidays and higher birth weight were also associated with increased childhood NHL risk. The combined OR of the two studies for the association of asthma with NHL risk was: 0.52, 95%CI:0.32-0.84, whereas for HL: 0.86, 95%CI:0.51-1.45. Allergy seems to be strongly and inversely associated with childhood NHL. It remains to be elucidated in future investigations comprising larger populations, focusing on specific disease subtypes and employing more pertinent study-designs, whether this association is genuinely protective., (Copyright © 2011 Elsevier Ltd. All rights reserved.)

Background: Cancer risk in children born after in vitro fertilization (IVF) remains largely unknown. We aimed to investigate risk of leukemia and lymphoma following IVF using two nationwide datasets., Methods: The hospital-based case-control study in Greece derived from the National Registry for Childhood Hematological Malignancies (1996-2008, 814 leukemia and 277 lymphoma incident cases with their 1:1 matched controls). The Swedish case-control study was nested in the Swedish Medical Birth Register (MBR) (1995-2007, 520 leukemia and 71 lymphoma cases with their 5,200 and 710 matched controls) with ascertainment of incident cancer cases in the National Cancer Register. Study-specific and combined odds ratios (OR) were estimated using conditional logistic regression, with adjustment for possible risk factors., Results: Nationwide studies pointed to similar size excess risk of leukemia following IVF, but to a null association between IVF and lymphoma. The proportion of leukemia cases conceived through IVF was 3% in Greece and 2.7% in Sweden; prevalence of IVF in matched controls was 1.8% and 1.6%, respectively. In combined multivariable analyses, the increased risk of leukemia was confined to age below 3.8 years (OR = 2.21; 95% confidence interval, CI: 1.27-3.85) and to acute lymphoblastic leukemia (ALL) (OR = 1.77; 95% CI: 1.06-2.95) with no sufficient evidence of excess risk for other leukemias (OR = 1.34; 95% CI: 0.38-4.69). Following IVF, OR for ALL was 2.58 (95% CI: 1.37-4.84) before age 3.8 and 4.29 (95% CI: 1.49-12.37) before age 2 years., Conclusions: IVF seems to be associated with increased risk of early onset ALL in the offspring., (Copyright © 2011 Wiley Periodicals, Inc.)

Background: Maternal smoking during pregnancy has been often implicated in the development of childhood leukemia with ambiguous results. Hence, we conducted a meta-analysis aiming to summarize current evidence and quantify any tentative impact., Procedure: We retrieved one cohort (553 leukemias compared to 1,440,542 children), 20 case-control studies and also analyzed the updated Greek case-control dataset with unpublished data, yielding in total 11,092 cases and 25,221 controls., Results: Odds ratios reported in the studies included ranged from 0.70 to 2.20 for acute lymphocytic (ALL) and from 0.60 to 2.17 for acute myelocytic leukemia (AML). The combined effect regarding the association of maternal smoking (any vs. no) and leukemia risk was 1.03 for ALL (95% CI = 0.95-1.12, random effects model) and 0.99 for AML (95% CI = 0.90-1.09, fixed effects model). The results remained unchanged when sensitivity analyses were undertaken of studies reporting same maternal smoking periods, those focusing only on childhood leukemia deaths or investigations which did not clearly define AML subtype., Conclusions: The findings of the meta-analysis challenge the limits of traditional epidemiology to provide sound inferences when point estimates of constituent studies range around the null. In particular, this study provides no support to a hypothesis linking maternal smoking during pregnancy with subsequent development of main childhood leukemia subtypes. Further investigations employing molecular and genetic epidemiology, however, might be needed in the hope to reveal even minimal risks pertaining individuals with specific susceptibility to tobacco compounds who sustain high environmental exposures prenatally or postnatally., (Copyright © 2011 Wiley Periodicals, Inc.)

Background: We set out to determine the epidemiology of pediatric brain tumors in a single Greek institute., Methods: We reviewed all cases of brain tumors in children, under the age of 15 years, that were treated surgically in the Neurosurgical Department of Children's Hospital "Agia Sofia", between January 1991 and December 2008., Results: From January 1991 through December 2008, we encountered 335 cases of pediatric brain tumors. The mean age was 7.2 years and there was a slight male predominance. Astrocytomas made up the largest component, with pilocytic astrocytomas accounting for 25.6% of all tumors. The second most common entity was medulloblastoma, accounting for 18% of all tumors, whereas ependymomas were the third most frequent tumor. There was an increase in the total number of brain tumors during the last decade. Furthermore, examining low-grade astrocytoma, medulloblastoma and ependymoma trends over the last 2 decades, we found a trend for a decrease of low-grade astrocytomas and an increase of the more aggressive medulloblastomas and ependymomas., Conclusion: This study presents the first epidemiological data of pediatric brain tumors in Greece. Astrocytomas were the most common tumor followed by medulloblastomas and ependymomas. Furthermore, a trend for an increase of malignant tumors over the last decade has been observed., (© Georg Thieme Verlag KG Stuttgart · New York.)

Background: The aim of this study was to determine the safety, tolerance and efficacy of linezolid for the treatment of infections from Gram-positive bacteria in immunocompromised children with cancer., Methods: This was a prospective non-comparative unblinded study in the Hematology/Oncology Unit over a two-year period, administering linezolid as monotherapy in children with cancer., Results: Seventeen children received linezolid (30 mg/kgr: 3 i.v. per day). Mean duration of linezolid administration was 12.2 days (range, 6-38 days), while the median age of the evaluable patients was 2.2 years (range, 6 months-11.2 years). Primary diagnosis was acute lymphoblastic leukemia (nine patients), brain tumor (three patients), multi-organ Langerhans cell histiocytosis (two patients), rhabdomyosarcoma, Burkitt's lymphoma and ovarian tumor (one patient each). All patients were in the midst of chemotherapy cycles. Ten out of 17 children had positive blood cultures (methicillin-resistant Staphylococcus aureus, four patients; vancomycin-resistant Enterococcus, three patients; penicillin-resistant Streptococcus pneumoniae, three patients), while seven of the 17 had fever and vancomycin-resistant Enterococcus in stool cultures. All patients were considered clinically cured after the end of the linezolid regimen (100% efficacy). The main adverse events were thrombocytopenia grade 1-3 and anemia grade 2-3 (four and two patients, respectively). Chemotherapy-induced myelotoxicity (six patients) was not worsened during linezolid therapy. No bleeding episodes were presented. Self-limited diarrhea grade 1-2 was presented in four patients (mean duration 2 days). The total adverse event rate was 23.5%; however, there was no premature cessation of linezolid in any patient., Conclusions: Linezolid may be another effective and safe therapy to treat infections from resistant Gram-positive bacteria in immunocompromised children, even in young ages., (© 2010 The Authors. Pediatrics International © 2010 Japan Pediatric Society.)

This case-control study aims to explore the association of serum adiponectin/leptin with childhood Hodgkin lymphoma (HL). Study participants were 75 children with histologically confirmed HL, registered in the Nationwide Registry for Childhood Haematological Malignancies and 75 age- and gender-matched controls. Multiple conditional logistic regression analyses were performed, adjusting for sociodemographic and lifestyle parameters. Adiponectin levels were consistently higher among cases in all models with ORs >1.25; 95% CIs ranging from 0.9 to 1.8 and P-values from 0.09 to 0.20. By contrast, there was no association of serum leptin with HL. In conclusion, elevated serum adiponectin might be a risk factor for childhood HL., ((c) 2009 Wiley-Liss, Inc.)

Background: Monitoring time trends in the incidence of childhood leukaemias and lymphomas requires efficient and continuous data collecting systems. In countries without official cancer registries, such as Greece, ad hoc nationwide registration of incident childhood leukaemias and lymphomas could help elucidate the underlying aetiology and monitor socioeconomic differentials in health care delivery., Methods: We registered all cases and produced age, gender, type and immunophenotype specific figures and overall crude and age adjusted annual incidence rates and secular trends for 863 leukaemia and 311 lymphoma incident cases diagnosed in children <15 years of age across Greece during 1996-2006, namely the first 11 years of the Nationwide Registry for Childhood Hematological Malignancies., Results: The epidemiological profiles of leukaemias/lymphomas in Greece are similar to those in industrialised countries. No secular trends are observed for either malignancy during the studied period. However, the calculated incidence for leukaemia (46.60 cases per 1 million children annually) is among the highest in the EU-27 (19% higher than average; p<0.001), whereas that for lymphoma (16.8 cases per 1 million children annually) is around the EU-27 average., Conclusions: Minimal secular changes in childhood leukaemias/lymphomas have been noted recently in the EU-27, which cannot be easily explained in countries with small populations. Therefore, centralised EU databases such as the Automated Childhood Cancer Information System (ACCIS) should be enlarged to generate sufficient statistical power for monitoring time trends. It would be interesting to explore whether different lifestyle patterns across the EU might be responsible for the observed excess leukaemia incidence in countries such as Greece.

Introduction: The aim of the present study is to (a) describe the level of agreement between reports of health-related quality of life (HRQL) obtained from parents and young patients both on- and off-treatment and (b) explore the factors that may affect the level of agreement in the quality of life (QoL) between young patients and parental proxies., Patients and Methods: The study group consisted of 149 young patients (77 children and 72 adolescents) with cancer followed up by an oncology in-patient clinic of a Greek children's hospital with one of their parents (n=298). After parental consent was obtained, data were collected using the Pediatric Quality of Life Inventory (PedsQL) and a sociodemographic data form., Results: The data collection showed that the best agreement was for the physical (ICC=0.82) and the school domains (ICC=0.68), whereas the worst was for the emotional (ICC=0.48) and the social domains (ICC=0.52). In the off-treatment group, the mother's age was a significant predictor of the child-proxy difference on the physical sub-scale (F=9.804, P=0.003). There was a negative relationship between the mother's age and patient proxy difference on the physical sub-scale. In the on-treatment group, the educational level of the father was found to be a significant predictor for the physical (F=4.30, P=0.041), school (F=5.51, P=0.022) and total sub-scales (F=10.41, P=0.002). Parents with basic education tended to have worse agreement with their children's reports on the physical and school sub-scales, while parents with higher education had worse agreement with their children's reports on the total sub-scale., Conclusions: Our findings suggest that the children and adolescents with cancer reported better QoL than their parents. The predictors found to be significant need to be examined extensively by further studies.

The objective of this study was to quantify improvements in survival due to chemotherapy among children with medulloblastoma treated during the last three decades at a university unit in Greece, compare these gains with figures derived from a specialized unit in the United States and explore the role of extrinsic factors affecting survival. The records of all children with medulloblastoma (n=50) treated at the University Childhood Oncology Unit in Athens, Greece during the period 1973-2003 were reviewed. The role on survival of socio-demographic factors was studied by modeling the data through Cox's proportional-hazards regression, controlling for the mode of treatment (chemotherapy, yes vs. no), whereas survival of children with medulloblastoma treated in Greece was compared with that of 76 children treated in a specialized center in the United States during a respective period. After adjustment for demographic factors, children with medulloblastoma who received adjuvant therapy in Greece had an approximately four times higher instantaneous rate of remaining alive than those who did not (P=0.05). The 5-year survival of children with medulloblastoma treated at specialized medical centers in Greece and the United States was 66 and 63%, respectively. Despite the comparable figure with that of an acceptable standard, however, there was a suggestion (P=0.07) that a rural place of residence in Greece is a poor prognostic indicator. Assuming inherently similar age of occurrence in urban and rural areas, children from rural areas in this study had a more advanced age at diagnosis than those residing in urban Greece (mean age: 7.9 vs. 6.6 years) with a 5-year survival of 57 and 73%, respectively. As expected, incorporation of adjuvant chemotherapy in the treatment of Greek children with medulloblastoma has yielded remarkable improvement in 5-year survival, comparable to that of technologically advanced countries. On the contrary, children residing in rural areas of the country seem to enjoy less favorable prognosis, possibly owing to delays in diagnosis or limited access to optimal treatment facilities.

Background: This retrospective study was designed to estimate the incidence of primary gastric non-Hodgkin lymphoma (NHL) in childhood and the possible association with Helicobacter pylori (H. pylori)., Procedure: We reviewed and analyzed the charts of 135 patients with NHL that were diagnosed and treated in a single oncology unit during the last 20 years., Results: Only two patients, 5 and 12 years old, with primary gastric NHL were found. Upper gastroduodenal endoscopy detected an ulcer in the lesser curvature of the body of the stomach, in both cases. Endoscopy revealed a moderate chronic gastritis in the antrum of both patients that was H. pylori associated in one of them who also suffered from chronic gastritis. Biopsy specimens demonstrated infiltration by Burkitt lymphoma (BL). The two patients received chemotherapy for 6 months. Additionally, one of the two patients received a triple therapy regimen with bismuth, amoxicillin, and metronidazole for H. pylori. Fifteen and six years later they are in complete remission, free of symptoms., Conclusions: Primary gastric NHL in childhood is rare. It was found in fewer than 2% of our NHL patients. The temporal relationship between the H. pylori infection and BL suggest a causative link between these two events., (Copyright 2003 Wiley-Liss, Inc.)