Case-control study of perinatal factors and hepatoblastoma in children with an extremely low birthweight

Hepatoblastoma diagnosed in infancy occurring in single-ventricle patients: a case series

Hepatoblastoma is the most common primary liver tumour in children; however, there are no reported incidences in the single-ventricle congenital heart disease population. We present three cases in patients with single-ventricle heart disease with a mean age at diagnosis of 19.7 (±4) months. The diagnosis was made prior to Fontan completion in all three cases. These represent the only documented hepatoblastoma cases in single-ventricle patients.

Oxygen and pulmonary vasodilation: The role of oxidative and nitrosative stress

Respiratory failure complicates up to 2% of live births and contributes significantly to neonatal morbidity and mortality. Under these conditions, supplemental oxygen is required to support oxygen delivery to the brain and other organs, and to prevent hypoxic pulmonary vasoconstriction. However, therapeutic oxygen is also a source of reactive oxygen species that produce oxidative stress, along with multiple intracellular systems that contribute to the production of free radicals in pulmonary endothelium and vascular smooth muscle. These free radicals cause vasoconstriction, act on multiple sites of the nitric oxide pathway to reduce cGMP-mediated vasodilation, and nitrate and inactivate essential proteins such as surfactant. In addition to oxygen, antenatal stressors such as placental insufficiency, maternal diabetes, and fetal growth restriction increase pulmonary and vascular oxidant stress and may amplify the adverse effects of oxygen. Moreover, the effects of free radical damage may extend well beyond infancy as suggested by the increased risk of childhood malignancy after neonatal exposure to hyperoxia. Antioxidant therapy is theoretically promising, but there are not yet clinical trials to support this approach. Targeting the abnormal sources of increased oxidant stress that trigger abnormal pulmonary vascular responses may be more effective in treating disease and preventing long term consequences.

Gestational risk factors and childhood cancers: A cohort study in Taiwan

Gestational risk factors such as birth weight, gestational age and parity have been repeatedly found to be related to pediatric cancers, but few reports have emerged from Asian countries. Here we report on demographic and gestational factors in a Taiwanese cohort. Our study included all children born in Taiwan 2004-2014 for whom there was a birth record (n = 2,079,037), of which 1900 children had been diagnosed with cancer prior to age 12. We conducted multivariable hazard regression to examine associations between demographic and gestational factors with cancer. Greater parity (family with 2+ older children) was related to acute myeloid leukemia [Hazard ratio (HR) = 2.15, 95% confidence interval (CI): 1.31, 3.55), central nervous system tumors (HR = 1.67, CI: 1.13, 2.48) and neuroblastoma (HR = 1.67, CI: 1.07, 2.63). Hepatoblastoma cases had a higher risk of low birth weight (<2,500 g; HR = 3.01, CI: 1.85, 4.91), very preterm birth (<33 weeks gestation; HR = 13.71, CI: 7.45, 25.23), plural pregnancies (HR = 2.37, CI: 1.10, 5.14) and both small (HR = 2.13, CI: 1.23, 3.67) and large (HR = 1.83, CI: 1.01, 3.32) for gestational age. Germ cell tumors were more common among children born in rural areas (HR = 1.63, CI: 1.02, 2.60). Despite that Taiwan has lower rates of both high and low birthweight compared to other developed nations, we observed several similar associations to those reported in Western Countries. Further research should examine unique exposures in Taiwan that may be contributing to higher incidence of certain cancer types.

Is yolk sac tumor related to the pathophysiology of low birthweight?

An 8-year-old Japanese girl was admitted with an ovarian yolk sac tumor. Regarding birth history, the patient had been delivered by cesarean section at 25 weeks of gestation with a birthweight of 711g. She had required neonatal intensive care including oxygenation, various medications, and tests. After surgery and chemotherapy, there was no recurrence for 2 years, at the time of writing. Yolk sac tumor, which is a malignant germ cell tumor, is rare in children. Although the cause and risk factors are unclear, it has been reported that malignant germ cell tumors in childhood have been associated with pathophysiology at birth. Given that premature infants are more likely to survive due to advances in perinatal care, it is expected that such cases will increase in the near future. We suggest that children born prematurely require careful follow up.

Abdominal transplantation for unresectable tumors in children: the zooming out principle

PURPOSE

To present our experience in abdominal transplantations to manage unresectable abdominal neoplasms in children and to describe the role of extensive surgeries in such cases.

METHODS

This is a retrospective study of 22 abdominal transplantations in 21 patients for abdominal tumors over 16 years. Transplantation techniques included liver transplant (LT), multivisceral transplant (MVTx), and intestinal autotransplant (IA). Follow-up intervals ranged from 0.3 to 168 months (median 20 months).

RESULTS

LT alone was performed in 15 patients for primary malignant (11) and benign (4) liver tumors. Pathological classification included HB hepatoblastoma (6), HCC hepatocellular cancer (3), hepatic epithelioid hemangioendothelioma HEH (1), angiosarcoma (1), benign vascular tumors (3), and adenoma (1). IA was performed in four patients for lesions involving the root of the mesentery; tumors of the head of pancreas (3) and mesenteric hemangioma (1). MVTx was performed in 2 patients for malignancies; pancreaticoblastoma (1), recurrent hepatoblastoma (1), and in one patient as a rescue procedure after IA failure. Four of the eleven patients who underwent LT for malignant liver tumor had metastatic disease at presentation. Six of them died of recurrent neoplasm (3), transplant-related complications (2), and underlying disease (1). All LT patients who had benign tumors are alive with functioning grafts. All IA patients survived and are on an oral diet, with one patient requiring TPN supplementation. One of the three patients who underwent MVTx died of metastatic disease.

CONCLUSIONS

Allo/auto transplantation for abdominal tumors is a valuable modality when conventional treatments fail or are not feasible.

Trends in incidence of childhood malignant solid tumors in Japan: Estimation based on hospital-based registration

BACKGROUND/PURPOSE

In Japan, an increase in hepatoblastoma with low birth weight has become evident since the 1990 s, and there is concern about a possible increase in unfavorable neuroblastomas after the cessation of mass screening in 2004.

METHODS

The trends in incidence of malignant solid tumors in children younger than 15 years of age were inferred by evaluating registration incidence in the registry of the Japanese Society of Pediatric Surgeons.

RESULTS

A significant trend toward an increase in the registration incidence for hepatoblastoma was observed (p<0.001). Hepatoblastomas with low birth weight (<1500 g) represented as many as 16% of hepatoblastomas. In hepatocellular carcinoma, there was a significant trend toward a decrease (p=0.042). The registration incidence of nonmass screening-detected neuroblastoma remained unchanged until 2003, but the registration incidence in the period from 2004 to 2012 was significantly higher than that in the period from 1996 to 2003 (p=0.021). There was an increase in the relative incidence of favorable stages after the cessation of mass screening.

CONCLUSIONS

The notable increase in hepatoblastoma during the last three decades is partly attributed to an increase in hepatoblastoma in children of low birth weight, but this alone is not sufficient to explain the increase in hepatoblastoma. The increase in neuroblastoma after the halt of mass screening is so minimal that it is not recommended to consider reimplementation of mass screening.

Incidence, Trends, and Survival of Children With Embryonal Tumors

BACKGROUND

Central nervous system (CNS) and non-CNS embryonal tumors occur principally in children and are rarely seen in adults. The incidence rates for rare entities such as atypical teratoid/rhabdoid tumors (AT/RT) or primitive neuroectodermal tumors in the CNS are rarely published. Incidence rates for certain subgroups, such as hepatoblastomas, have been increasing in some countries.

METHODS

Data of 8337 embryonal tumors, registered in children (0-14 years) between 1991 and 2012 (for AT/RT 2000-2012) in the population-based German Childhood Cancer Registry with complete national coverage were analyzed for incidence rates, time trends, and survival.

RESULTS

For most entities, the incidence rates were the highest for children <1 year. An important exception was medulloblastomas, which occurred mainly in 1- to 9-year-olds. Neuroblastomas and ganglioneuroblastomas as well as Wilms tumors (nephroblastomas) had the highest age standardized incidence rates (13.7 and 9.4 per million, respectively). A statistically significant increasing trend for hepatoblastomas (annual average percent change 4.6%) was detected. The survival probabilities varied between the diagnostic groups: primitive neuroectodermal tumors and AT/RT had the lowest and retinoblastomas the highest. The survival was dependent on the age at diagnosis, the most extreme examples being neuroblastomas, for which the survival probability declined steeply for children ≥1 year and medulloblastomas, for which the highest survival was seen for 10- to 14-year-olds.

CONCLUSIONS

This study presents a comprehensive overview of pediatric embryonal tumors from a well-established, complete nationwide cancer registry. Significant increasing trend for hepatoblastomas was detected for the first time in Europe.

Lung cancer incidence decreases with elevation: evidence for oxygen as an inhaled carcinogen

The level of atmospheric oxygen, a driver of free radical damage and tumorigenesis, decreases sharply with rising elevation. To understand whether ambient oxygen plays a role in human carcinogenesis, we characterized age-adjusted cancer incidence (compiled by the National Cancer Institute from 2005 to 2009) across counties of the elevation-varying Western United States and compared trends displayed by respiratory cancer (lung) and non-respiratory cancers (breast, colorectal, and prostate). To adjust for important demographic and cancer-risk factors, 8-12 covariates were considered for each cancer. We produced regression models that captured known risks. Models demonstrated that elevation is strongly, negatively associated with lung cancer incidence (p < 10(-16)), but not with the incidence of non-respiratory cancers. For every 1,000 m rise in elevation, lung cancer incidence decreased by 7.23 99% CI [5.18-9.29] cases per 100,000 individuals, equivalent to 12.7% of the mean incidence, 56.8. As a predictor of lung cancer incidence, elevation was second only to smoking prevalence in terms of significance and effect size. Furthermore, no evidence of ecological fallacy or of confounding arising from evaluated factors was detected: the lung cancer association was robust to varying regression models, county stratification, and population subgrouping; additionally seven environmental correlates of elevation, such as exposure to sunlight and fine particulate matter, could not capture the association. Overall, our findings suggest the presence of an inhaled carcinogen inherently and inversely tied to elevation, offering epidemiological support for oxygen-driven tumorigenesis. Finally, highlighting the need to consider elevation in studies of lung cancer, we demonstrated that previously reported inverse lung cancer associations with radon and UVB became insignificant after accounting for elevation.

Neonatal medical exposures and characteristics of low birth weight hepatoblastoma cases: a report from the Children's Oncology Group

BACKGROUND

Hepatoblastoma is a malignancy of young children. Low birth weight is associated with significantly increased risk of hepatoblastoma and neonatal medical exposures are hypothesized as contributors. This study represents the largest case-control study of hepatoblastoma to date and aimed to define the role of neonatal exposures in hepatoblastoma risk among low birth weight children.

PROCEDURE

Incident hepatoblastoma cases who were born <2,500 g (N = 60), diagnosed between 2000 and 2008, were identified through the Children's Oncology Group. Controls were recruited through state birth registries (N = 51). Neonatal medical exposures were abstracted from medical records. Subjects from the Vermont Oxford Network were used for further comparisons, as were existing reports on neonatal medical exposures.

RESULTS

Case-control comparisons were hindered by poor matching within birth weight strata. Cases were smaller and received more aggressive neonatal treatment compared to controls, and reflected high correlation levels between birth weight and treatments. Similar difficulty was encountered when comparing cases to Vermont Oxford Network subjects; cases were smaller and required more aggressive neonatal therapy. Furthermore, it appears hepatoblastoma cases were exposed to a greater number of diagnostic X-rays than in case series previously reported in the neonatal literature.

CONCLUSIONS

This study presents the largest case series of hepatoblastoma in <2,500 g birth weight infants with accompanying neonatal medical exposure data. Findings confirm that birth weight is highly correlated with exposure intensity, and neonatal exposures are themselves highly correlated, which hampers the identification of a causal exposure among hepatoblastoma cases. Experimental models or genetic susceptibility testing may be more revealing of etiology.

Children's Oncology Group's 2013 blueprint for research: epidemiology

Investigators worldwide have for over 40 years conducted case-control studies aimed at determining the causes of childhood cancer. The central challenge to conducting such research is the rarity of childhood cancer, thus many studies aggregate cases through clinical trials organizations such as COG. Rarity also precludes the use of prospective study designs, which are less prone to recall and selection biases. Despite these challenges a substantial literature on childhood cancer etiology has emerged but few strong environmental risk factors have been identified. Genetic studies are thus now coming to the fore with some success. The ultimate aim of epidemiologic studies is to reduce the population burden of childhood cancer by suggesting preventive measures or possibly by enabling early detection. Pediatr Blood Cancer 2013; 60: 1059-1062. © 2012 Wiley Periodicals, Inc.

Case-control study of birth characteristics and the risk of hepatoblastoma

BACKGROUND

Hepatoblastoma is a malignant embryonal tumor typically diagnosed in children younger than five years of age. Little is known on hepatoblastoma etiology.

METHODS

We matched California Cancer Registry records of hepatoblastomas diagnosed in children younger than age 6 from 1988 to 2007 to birth records using a probabilistic record linkage program, yielding 261 cases. Controls (n=218,277), frequency matched by birth year to all cancer cases in California for the same time period, were randomly selected from California birth records. We examined demographic and socioeconomic information, birth characteristics, pregnancy history, complications in pregnancy, labor and delivery, and abnormal conditions and clinical procedures relating to the newborn, with study data taken from birth certificates.

RESULTS

We observed increased risks for hepatoblastoma among children with low [1500-2499 g, Odds Ratio (OR)=2.02, 95% confidence interval (CI) 1.29-3.15] and very low birthweight (<1500 g, OR=15.4, 95% CI 10.7-22.3), preterm birth <33 weeks (OR=7.27, 95% CI 5.00, 10.6), small size for gestational age (OR=1.75, 95% CI 1.25-2.45), and with multiple birth pregnancies (OR=2.52, 95% CI 1.54-4.14). We observed a number of pregnancy and labor complications to be related to hepatoblastoma, including preeclampsia, premature labor, fetal distress, and congenital anomalies.

CONCLUSION

These findings confirm previously reported associations with low birthweight and preeclampsia. The relation with multiple birth pregnancies has been previously reported and may indicate a relation to infertility treatments.

The epidemiology of hepatoblastoma

Few causes of hepatoblastoma have been conclusively identified, mainly due to the extreme rarity of the disease. Inherited conditions including Familial Adenomatous Polyposis and Beckwith-Wiedemann Syndrome dramatically raise risk of hepatoblastoma but account for few cases overall. A small number of case-control studies investigating risk factors for sporadic hepatoblastoma have been conducted to date. Although most of these studies feature fewer than 200 cases, several clues have emerged. Most notably there is a roughly 20-fold increased risk of hepatoblastoma among children with very low birth weight (<1,500 g) and a doubling of risk among those with moderately low birth weight (1,500-2,500 g). A modicum of evidence points to a possible role of parental tobacco use prior to or during pregnancy in the causation of hepatoblastoma as well.

Primary malignant liver tumors in children

Liver tumors constitute only 1-4% of all solid tumors in children. Two-thirds of these are malignant. The primary malignant tumors are hepatoblastoma (HB), hepatocellular carcinoma (HCC), rhabdomyosarcoma (RMS), angiosarcoma, rhabdoid tumor, undifferentiated sarcoma and other rarer tumors. Of these HB is the commonest. The diagnosis of HB is based on the radiology, elevated levels of α-fetoprotein (αFP) and the histology/cytology. Staging is essential for risk categorization, risk adapted treatment and prognostication. The commonest staging and risk categorization system used today is PRETEXT system that is being used by nearly all multicentre trials (American, European, German, Japanese) in some way. Treatment of HB is multimodal with surgery and chemotherapy being the main modalities. Survival is not possible without complete surgical resection. Majority of tumors are unresectable at presentation but can be made resectable with chemotherapy, giving a resection rate of more than 85%. Cisplatin is the main stay of chemotherapy and is a part of all multidrug protocols. The 3-y overall survival (OS) today stands at 62%-70% but only 25% patients with metastasis get cured. Panhepatic tumors and those with local factors causing unresectability are now dealt with liver transplantation which has also given a survival rate of nearly 85%. The overall management of HB and HCC has evolved over the past 3 decades giving good long term survival rates for HB, though patients with HCC still do poorly. Successive therapeutic trials have focused attention on increasing the efficiency and reducing the toxicity and long term side effects of the treatment. Among the other uncommon tumors the rhabdoid tumor and angiosarcoma are chemoresistant and have a poor outcome while the undifferentiated sarcoma and rhabdomyosarcoma are now showing better response to the currently used chemotherapy combinations.

Hepatoblastoma in the Nordic countries

Little is known about the etiology of hepatoblastoma. Because of the young age at diagnosis, several studies have looked at various birth characteristics. The purpose of our study was to investigate the incidence of hepatoblastoma in the Nordic countries and the association between selected birth characteristics and hepatoblastoma. Data from national cancer registries and birth registries in Denmark, Sweden, Norway and Finland 1985-2006 was used. Overall, 155 children with hepatoblastoma aged 0-14 years were included and individually matched to five controls drawn randomly from national population registries. The incidence rate of hepatoblastoma was 1.7 per million person-years with a predominance of boys (1.5:1). Incidence rate was highest before the age of 1 year (8.3 per million person-years). A higher risk of hepatoblastoma was found in children with birth weight <1,500 g [odds ratio (OR) = 9.5; 95% confidence interval (CI): 2.3-38.2], born preterm in week 22-32 (OR = 4.5; CI: 1.8-11.5) and Apgar scores <7 after 1 min (OR = 3.1; CI: 1.3-7.1) and 5 min (OR = 7.5; CI: 1.8-32.4). A doubling in risk was found in children who were large for gestational age (OR = 2.3; CI: 1.0-5.3). No associations were found with birth order, maternal age or maternal smoking. Our study indicates that intrauterine and/or neonatal factors are associated with increased risk of hepatoblastoma. These may include low birth weight and asphyxia leading to neonatal intensive care. Alternatively, the factors may be a consequence of hepatoblastoma developing in utero.

Accumulation of 8-oxoguanine in liver DNA during hyperoxic resuscitation of newborn mice

Supplementary oxygen during resuscitation of the asphyxiated newborn is associated with long-term detrimental effects including increased risk of childhood cancer. It is suspected that the resuscitation procedure results in accumulated DNA damage and mutagenesis. Base excision repair (BER) is the major pathway for repair of premutagenic oxidative DNA lesions. This study addresses DNA base damage and BER in brain, lung, and liver in neonatal mice (P7) after hyperoxic resuscitation. Mice were randomized to 8% oxygen or room air for 60 min in a closed chamber and subsequent reoxygenation with 100% oxygen for 0 to 90 min. During this treatment, 8-oxoguanine accumulated in liver but not in lung or cerebellum. We observed a linear relation between 8-oxoguanine and reoxygenation time in liver DNA from hypoxic animals (n = 28; B = 0.011 [0.001, 0.020]; p = 0.037). BER activity was not significantly changed during resuscitation. Our data suggest that after hypoxia, the capacity for immediate repair in liver tissue is inadequate to meet increasing amounts of DNA damage. The duration of supplementary oxygen use during resuscitation should be kept as short as justifiable to minimize the risk of genetic instability.

Cancer risk among children with very low birth weights

OBJECTIVE

The risk of hepatoblastoma is strongly increased among children with very low birth weight (<1500 g). Because data on very low birth weight and other childhood cancers are sparse, we examined the risk of malignancy with very low birth weight in a large data set.

METHODS

We combined case-control data sets created by linking the cancer and birth registries of California, Minnesota, New York, Texas, and Washington states, which included 17672 children diagnosed as having cancer at 0 to 14 years of age and 57966 randomly selected control subjects. Unconditional logistic regression analysis was used to examine the association of cancer with very low birth weight and moderately low birth weight (1500-1999 g and 2000-2499 g, respectively), compared with moderate/high birth weight (>or=2500 g), with adjustment for gender, gestational age, birth order, plurality, maternal age, maternal race, state, and year of birth.

RESULTS

Most childhood cancers were not associated with low birth weights. However, retinoblastomas and gliomas other than astrocytomas and ependymomas were possibly associated with very low birth weight. The risk of other gliomas was also increased among children weighing 1500 to 1999 g at birth.

CONCLUSIONS

These data suggested no association between most cancers and very low birth weight, with the exception of the known association of hepatoblastoma and possibly moderately increased risks of other gliomas and retinoblastoma, which may warrant confirmation.

Pediatric liver tumors--a pictorial review

Hepatic masses constitute about 5-6% of all intra-abdominal masses in children. The majority of liver tumors in children are malignant; these malignant liver tumors constitute the third most common intra-abdominal malignancy in the pediatric age group after Wilms' tumor and neuroblastoma. Only about one third of the liver tumors are benign. A differential diagnosis of liver tumors in children can be obtained based on the age of the child, clinical information (in particular AFP) and imaging characteristics. The purpose of this review is to report typical clinical and imaging characteristics of benign and malignant primary liver tumors in children.

Perinatal risk factors for hepatoblastoma

We confirmed the strong association of hepatoblastoma with very low birth weight (relative risk <1000 g vs >or=2000 g=25.6; 95% confidence interval: 7.70-85.0) and demonstrated independent associations with congenital abnormalities and maternal Asian race in a population-based Minnesota study that included 36 cases and 7788 controls.

Treatment outcomes for hepatoblastoma: an institution's experience over two decades

Our objective is to review a leading Australian tertiary referral centre's experience in treating hepatoblastoma over two decades. This is a retrospective study of clinical, radiological and pathological data in hepatoblastoma patients treated at our institution between 1984 and 2004. Thirty children (17 male, 13 female) ranging in age from 5 months to 6.5 years (median 19 months) at diagnosis were reviewed. This is the largest case series reported in Australia to date. The median length of follow-up was 6.3 years (range 7 months to 20.9 years). On average, the number of new cases increased by 0.12 each year (P=0.01). A total of 29 patients underwent definitive surgery for primary tumour control. Of these, two (7%) had initial primary surgery, while 27 (93%) had delayed surgery following neo-adjuvant chemotherapy. Chemotherapy regimens included the SIOPEL study protocols. Patients not enrolled in SIOPEL tended to be given more courses of chemotherapy. Ten patients (34%) received an extended right hemi-hepatectomy, six (21%) had right hemi-hepatectomy, seven (24%) had left hemi-hepatectomy, three (10%) had left lateral segmentectomy, and two (7%) had a non-anatomical resection. In addition, two patients required IVC reconstruction at the time of their primary liver resection. Overall survival at 5 years was 89.1% (95% CI 69.8-96.4%). Event-free survival at 5 years was 75.7% (95% CI 53.2-88.5%). There was a clear increase in the risk of recurrence (RR=4.8) and death (RR=4.5) where margins were not microscopically clear. However, neither reached statistical significance in this small cohort. Surgery was still worthwhile even when margins were involved. There was no correlation between mean AFP level at diagnosis, and outcome. Our experience suggests that the achievement of microscopically clear margins at the time of primary tumour resection is an important factor in achieving a positive long-term outcome. In addition, extended courses of neo-adjuvant chemotherapy in patients with pulmonary metastases achieves good long-term outcomes, provided adequate surgical resection of the primary tumour with clear microscopic margins can be achieved.

Maternal and infant birth characteristics and hepatoblastoma

Hepatoblastoma is a rare embryonal tumor with unknown etiology. The authors conducted a case-cohort study using public health surveillance data sets to examine perinatal risk factors for hepatoblastoma. Hepatoblastoma cases (n = 58) diagnosed between 1985 and 2001 were identified from the New York State Cancer Registry and were matched to electronic birth records for 1985-2001 from New York State, excluding New York City. Controls (n = 6,056) were selected from the birth cohorts for the same years. Having a birth weight less than 1,000 g was associated with a strongly increased risk of hepatoblastoma (relative risk (RR) = 56.9, 95% confidence interval (CI): 24.0, 130.7). After adjustment for birth weight, a moderately increased risk of hepatoblastoma was found for younger maternal age (<20 years vs. 20-29 years: RR = 2.5, 95% CI: 1.0, 5.5), presumptive use of infertility treatment (RR = 9.2, 95% CI: 2.1, 31.5), maternal smoking (RR = 2.1, 95% CI: 1.0, 4.2), and higher maternal prepregnancy body mass index (body mass index of 25-29 vs. 20-24: RR = 2.9, 95% CI: 1.2, 7.6).

Factores de riesgo asociados a los tumores neonatales. Experiencia de una unidad de salud medioambiental pediátrica (PEHSU-Valencia)

BACKGROUND

Neonatal tumors (NT) result from a variable combination of constitutional and environmental determinants. Multiple risk factors (RF) are involved in their development, although most are unknown.

OBJECTIVE

To document the constitutional, environmental, preconceptional and transplacental RF associated with the development of NT with greater or lesser scientific evidence.

PATIENTS AND METHODS

We investigated known RF in NT diagnosed at La Fe University Children's Hospital from January 1990 to December 1999, using a questionnaire completed by parents in a personal interview, either at the Pediatric Environmental Health Specialty Unit (PEHSU-Valencia) or at their home. RF associated with NT and childhood cancer were identified through a literature review of the last 25 years through Medline, Cancerlit, Science Citation Index, and Embase.

RESULTS

The questionnaire was completed in 59 of 74 NT diagnosed during the period studied. All patients were Caucasians born in Spain. Constitutional-genetic factors were identified in 13.6 %: dominant hereditary syndromes in 5 (familial retinoblastoma in 1 and tuberous sclerosis in 4), and non-hereditary chromosomal syndromes in 3 (trisomy 21). Notable environmental factors were: a) ionizing radiation: preconceptional exposure in 32.2 % and in utero exposure in 6.8 %; b) non-ionizing radiation; 54.2 % reported preconceptional exposure and in utero exposure at home; c) pregnancy-related problems: infections in 13.6 % (8 patients) and a prior history of miscarriage in 20.3 %; d) drugs/chemicals administered during pregnancy: capillary dye in 42.4 %, daily facial make-up in 45.8 %, antacids in 30.5 %, acetaminophen in 34 %, hormone therapy in 10 %, cocaine and marijuana consumption in 11.7 %; e) tobacco: exposure to active smoking in 93.2 % of patients; f) alcohol: in utero exposure in 6.8 %; g) occupational exposure in parents: paternal in 49 % of cases (hydrocarbons in 15, metal in 3, chemical in 2, timber in 2, and agriculture in 7). Four were exposed to pesticides, 3 to solvents, and 3 to paints; and maternal in 12 cases (20 %): low frequency non-ionizing radiation in 6 (textile in 5, and railway in 1), 5 in the service sector (2 hairdressers, 3 cleaners), and 1 the in chemical industry. In another 6 there was exposure to solvents and paints (footwear industry).

CONCLUSIONS

The hypotheses formulated in this observational study, which should be analyzed in future case-control and cohort studies, are: a) to scientifically document genetic-constitutional RF in the etiopathogenesis of NT; b) to determine the frequency and etiology of prior miscarriage and its possible association with NT; c) to determine the importance of active smoking before and during pregnancy as a RF for NT; d) to establish the importance of parental occupational exposure in the etiopathogenesis of NT; and e) to define more precisely the role of other physical and chemical RF in the development of NT. To determine and record the RF involved in the etiopathogenesis of NT, the environmental history should be documented in pediatric cancers. The identification of RF is one of the main objectives of Pediatric Environmental Health Specialty Units.

Childhood cancer following neonatal oxygen supplementation

OBJECTIVE

To evaluate the relationship between neonatal oxygen supplementation (O2) and childhood cancer in the Collaborative Perinatal Project (CPP).

STUDY DESIGN

The CPP consisted of 54,795 children born between 1959 and 1966 and followed to age 8 years. We used Cox proportional hazards modeling to examine the association between history of neonatal O2 and cancer (n = 48).

RESULTS

The hazard ratio (HR) for any O2 was 1.77 (95% confidence interval [CI] = 0.94 to 3.35). The HR for continuous duration of O2 was near 1 and not significant. However, the HRs were 0.69 (95% CI = 0.17 to 2.88) and 2.87 (95% CI = 1.46 to 5.66) when comparing 0 to 2 and 3 or more minutes of O2, respectively, to no O2. The latter association was weaker (HR = 2.00; 95% CI = 0.88 to 4.54) and not significant ( P = .10) when analysis was restricted to cancers diagnosed after age 1 year (n = 41).

CONCLUSIONS

These findings are consistent with an association between O 2 for 3 minutes or longer and cancer in childhood, and should serve as a basis for further study.

Relationships between perinatal and maternal characteristics and hepatoblastoma: a report from the UKCCS

Within the context of a national population-based case-control study--the United Kingdom Childhood Cancer Study (UKCCS)--we aimed to explore relationships between perinatal and maternal factors and childhood hepatic tumours, for participants with data available from medical records. 26/28 children with hepatic tumours (22/24 hepatoblastomas, 4/4 hepatocellular carcinomas (HCC)) and 4753 age- and sex-matched controls were included. Polyhydramnios was associated with 0.9% of control pregnancies and 13.6% of case pregnancies (Odds Ratio (OR)=28.64, 95% Confidence Interval (CI)=6.94-118.21, P<0.0001); eclampsia or severe pre-eclampsia complicated the pregnancies of 16.7% of mothers whose children developed hepatoblastoma compared with 0.5% of control pregnancies (OR=52.50, 95% CI=10.75-257.05, P<0.0001). Three children with hepatoblastoma weighed <1500 g at birth, two of whom weighed <1000 g (OR for birthweight <1500 g=69.00, 95% CI=11.98-397.17, P<0.0001). Of children with hepatoblastoma, 50% (11/22) had records of congenital anomalies, as did two of their mothers. Three mothers of children with hepatoblastoma had diagnoses of cancer--two of papillary carcinoma of the thyroid and one of acute lymphoblastic leukaemia (ALL). Paediatricians and others should be alert to the possibility of familial or genetic syndromes in children with hepatoblastomas. Potential links between maternal pre-eclampsia, low birthweight and subsequent malignancy merit further investigation. Hepatoblastoma is an extremely rare childhood tumour, but understanding the mechanism(s) underlying severe pre-eclampsia and eclampsia may also shed light on factors that contribute to the development of hepatoblastoma.

Hepatoblastoma in low birth weight infants: an institutional review

The association between hepatoblastoma and low birth weight documented recently in the literature has yet to be well explained, in particular the suggestion that these patients may have a more aggressive form of the disease. From 1989 to 2003, our institution treated four patients for hepatoblastoma who had birth weights of less than 1,500 g. Notable was 100% patient survival despite bilateral and, in one case, recurrent disease. Speculation regarding the etiology of this subset of hepatoblastoma has included damage to developing hepatocytes induced by oxygen free radicals. Our patients universally had pulmonary disease requiring prolonged supplemental oxygen and ventilatory support. However, our review supports no changes in the standard care of low birth weight infants or in managing those who develop hepatoblastoma.

Nongenetic causes of childhood cancers: evidence from international variation, time trends, and risk factor studies

Ionizing radiation and a variety of genetic conditions are thought to explain 5-10% of childhood cancers. Infection with Epstein-Barr virus (EBV) in parts of Africa and human immunodeficiency virus (HIV) increase the risk of Burkitt's lymphoma and Kaposi's sarcoma, respectively. Other risk factors have not been conclusively identified. A review of the data on international variation in incidence, recent changes in incidence, and risk factors suggests that many childhood cancers are likely to have nongenetic causes. The pattern of international variation and associations with surrogates of infection suggest an infectious etiology for acute lymphoblastic leukemia, although no agent has been identified. The biologic plausibility is strong that maternal consumption of food containing DNA topoisomerase II inhibitors may increase the risk of acute myeloid leukemia, although the data are limited now. For brain tumors, cured meats, polyomaviruses, and farm exposures may have etiologic roles. Changes in the incidence and characteristics of children with hepatoblastoma as well as risk factor studies suggest a role for an exposure of very low birth weight babies. High birth weight, tea or coffee consumption, and certain paternal occupations have shown some consistency in their association with Wilms' tumor. For most of the other cancers, very few epidemiologic studies have been conducted, so it is not surprising that nongenetic risk factors have not been detected. The most important difference between the cancers for which there are good etiologic clues and those for which there are not may be the number of relevant studies.

Birth characteristics and hepatoblastoma risk in young children

BACKGROUND

Although hepatoblastoma is a very rare childhood cancer, its incidence appears to be rising, especially among children with very low birth weight. With the exception of documented correlations with certain congenital anomalies, the etiology of hepatoblastoma remains largely unknown.

METHODS

Using California's population-based cancer registry, the authors identified 113 children ages birth-4 years with hepatoblastoma who were diagnosed between 1988 and 1997. Ninety-nine of those 113 children (88%) were matched to a California birth certificate, and randomly selected controls from the same birth certificate files were matched to cases (4:1) according to the month and year of birth and gender. Odds ratios (OR) and 95% confidence intervals (95% CI) were estimated using conditional logistic regression analyses.

RESULTS

A strikingly elevated risk of hepatoblastoma was found in children who were born with very low birth weight (< 1500 g; OR, 50.57; 95% CI, 6.59-387.97). A plot of the distribution by birth weight showed interesting peaks at birth weights < 1000 g and 3000-3499 g among cases. Children who weighed < 1000 g showed a statistically significant, linear trend toward being diagnosed at an older age (P = 0.036), which seemed to be explained in part by gestational age.

CONCLUSIONS

The results confirmed previously reported findings of an increased hepatoblastoma risk among children with very low birth weight and suggested that the etiology may differ between children with very low birth weight and children with normal birth weight.

The epidemiology of neonatal tumours. Report of an international working group

Neonatal tumours occur every 12,500-27,500 live births and comprise 2% of childhood malignancies, but there is little clarity as to their real prevalence, sites of origin and pathological nature as reported series vary. As an entity, neonatal tumours provide a unique window of opportunity to study tumours in which minimal environmental interference has occurred. The majority of tumours present with a mass at birth (e.g., teratomas, neuroblastomas, mesoblastic nephroma, fibromatosis), which are not infrequently identified on antenatal ultrasound. Histologically, teratoma and neuroblastoma remain the two main tumour types encountered with soft tissue sarcoma, renal tumours, CNS tumours and leukaemia being the next most common tumour types identified. Malignant tumours are uncommon in the neonatal period per se and benign tumours may have malignant potential. A particular problem exists in clinical classification, as histological features of malignancy do not always correlate with clinical behaviour. Benign tumours may also be life threatening because of their size and location. Other tumours may demonstrate local invasiveness, but no metastatic potential, and tumours that are clearly malignant may demonstrate unpredictable or uncertain behaviour. Screening programmes have brought more tumours to light, but do not appear to affect the overall prognosis. They may provide clues to the stage at which tumours develop in foetu. The aetiology of cancer in children is multifactorial and includes both genetic and environmental factors. The association between congenital abnormalities and tumours is well established (15% of neonatal tumours). Genetic defects are highly likely in neonatal tumours and include those with a high risk of malignancy (e.g., retinoblastoma), but also genetically determined syndromes with an increased risk of malignancy and complex genetic rearrangements. Tumours are mostly genetically related at a cellular level and factors influencing cellular maturation or apoptosis within the developing foetus may continue to operate in the neonatal period. Cytogenetics of neonatal neoplasms appear to differ from neoplasms in older children, thus possibly explaining some of the observed differences in clinical behaviour. Certain constitutional chromosome anomalies, however, specifically favour tumours occurring in the foetal and neonatal period. In support of this hypothesis, certain cytogenetic anomalies appear to be specific to neonates, and a number of examples are explored. Other environmental associations include ionizing radiation, drugs taken during pregnancy, infections, tumours in the mother and environmental exposure.

Myeloperoxidase promotor polymorphism and risk of hepatoblastoma

Myeloperoxidase (MPO) is a major enzyme found in neutrophils. Oxidation by MPO produces free radicals that demonstrate genotoxic properties. A polymorphism (G to A) within the promotor region of the MPO gene reduces transcription and expression. This polymorphism is associated with a protective effect against some cancers in adults including lung cancer. The objective of our study was to investigate the effect of this MPO polymorphism on the risk of hepatoblastoma, the most common cancer of the liver in childhood. By using PCR-SSCP, we determined the genotype at this polymorphism in 48 cases of Caucasian children with hepatoblastoma and 180 normal controls. Genotypes were confirmed by a second method using Aci I restriction enzyme restriction. We found that A allele was associated with reduced risk of hepatoblastoma of 50% (OR, 0.51; 95%CI, 0.27-0.93) and G/A or A/A genotype reduced the risk by 56% (OR, 0.44; 95%CI, 0.21-0.90). Our data suggest that A allele is a protective factor with regard to the risk of hepatoblastoma, perhaps by altering genotoxic properties of xenobiotic substances which may act as carcinogens.

Detection of hepatic oxidative DNA damage in patients with hepatoblastoma and children with non-neoplastic disease

BACKGROUND

The authors have revealed a significant association between hepatoblastoma and low birth weight. This study was done to explore the evidence that liver cells were oxidatively damaged, based on the hypothesis that oxidative damage to DNA is involved in the development of hepatoblastoma in children of low birth weight.

PROCEDURE

Oxidative DNA damage in the liver was examined by immunohistochemically detecting the presence of a DNA repair product, 8-hydroxy-2'-deoxyguanosine (8-OHdG), in five patients with hepatoblastoma and 14 children with non-neoplastic disease.

RESULTS

Positive staining for 8-OHdG was observed in all five patients with hepatoblastoma. Distribution of 8-OHdG positivity was diffuse in the intralobular area in one patient and was restricted to the periportal area of the lobules in four patients. There was no apparent correlation between birth weight of the patients, histological findings in the liver, and the distribution of 8-OHdG positivity. In children with non-neoplastic disease, 8-OHdG was detected in nine of 14 patients, and 8-OHdG was positive in the intralobular area of the liver parenchyma except in one patient.

CONCLUSIONS

These results suggest that the cause of oxidative DNA damage in patients with hepatoblastoma may be different from the cause, extensive parenchymal damage to the liver, in children with non-neoplastic disease, but the 8-OHdG formation is not specific to hepatoblastoma patients of low birth weight. Further studies to elucidate the true reason for the high incidence of hepatoblastoma in children of low birth weight are necessary.