In vitro fertilization and risk of childhood leukemia in Greece and Sweden

Assisted Reproductive Technology and Risk of Childhood Cancer Among the Offspring of Parents With Infertility: Systematic Review and Meta-Analysis

Background

The relationship between assisted reproductive technology (ART) and childhood cancer risk has been widely debated. Previous meta-analyses did not adequately account for the impact of infertility, and this study addresses this gap.

Objective

Our primary objective was to assess the relative risk (RR) of childhood cancer in infertile populations using ART versus non-ART offspring, with a secondary focus on comparing frozen embryo transfer (FET) and fresh embryo transfer (fresh-ET).

Methods

A literature review was conducted through PubMed, Embase, Cochrane, and Web of Science, with a cutoff date of July 10, 2024. The study was registered with the International Platform of Registered Systematic Review and Meta-Analysis Protocols (INPLASY 202470119). Inclusion criteria were based on the PICOS (Population, Intervention, Comparison, Outcomes, and Study Design) framework: infertile or subfertile couples (population), ART interventions (in vitro fertilization [IVF], intracytoplasmic sperm injection [ICSI], FET, and fresh-ET), non-ART comparison, and childhood cancer risk outcomes. Data abstraction focused on the primary exposures (ART vs non-ART and FET vs fresh-ET) and outcomes (childhood cancer risk). The risk of bias was assessed using the Newcastle-Ottawa Quality Assessment Scale, and the evidence quality was evaluated with the Grading of Recommendations Assessment, Development, and Evaluation (GRADE). Pooled estimates and 95% CIs were calculated using random effects models.

Results

A total of 18 studies were included, published between 2000 and 2024, consisting of 14 (78%) cohort studies and 4 (22%) case-control studies, all of which were of moderate to high quality. The cohort studies had follow-up periods ranging from 3 to 18 years. Compared with non-ART conception, ART conception was not significantly associated with an increased risk of childhood overall cancer (RR 0.95, 95% CI 0.71-1.27; GRADE quality: low to moderate). Subgroup analyses of IVF (RR 0.86, 95% CI 0.59-1.25), ICSI (RR 0.76, 95% CI 0.26-2.2), FET (RR 0.98, 95% CI 0.54-1.76), and fresh-ET (RR 0.75, 95% CI 0.49-1.15) showed similar findings. No significant differences were found for specific childhood cancers, including leukemia (RR 0.99, 95% CI 0.79-1.24), lymphoma (RR 1.22, 95% CI 0.64-2.34), brain cancer (RR 1.22, 95% CI 0.73-2.05), embryonal tumors (RR 1, 95% CI 0.63-1.58), retinoblastoma (RR 1.3, 95% CI 0.73-2.31), and neuroblastoma (RR 1.02, 95% CI 0.48-2.16). Additionally, no significant difference was observed in a head-to-head comparison of FET versus fresh-ET (RR 0.99, 95% CI 0.86-1.14; GRADE quality: moderate).

Conclusions

In conclusion, this study found no significant difference in the risk of childhood cancer between offspring conceived through ART and those conceived through non-ART treatments (such as fertility drugs or intrauterine insemination) in infertile populations. While infertility treatments may elevate baseline risks, our findings suggest that whether individuals with infertility conceive using ART or non-ART methods, their offspring do not face a significantly higher risk of childhood cancer. Further research, especially comparing infertile populations who conceive naturally, is needed to better understand potential long-term health outcomes.

Association Between Perinatal Factors and Childhood Lymphoma-A Pooled Analysis of the ESCALE and ESTELLE Studies (SFCE)

CONTEXT

There is much interest in the perinatal period in relation to childhood cancer aetiology, with most studies focussing on childhood leukaemia. This work aimed to investigate the associations between pregnancy-related and perinatal factors and childhood lymphoma.

METHODS

We conducted a pooled analysis of two French nationwide population-based case-control studies. Data on sociodemographic, perinatal and lifestyle factors were collected through maternal interviews. Odds ratios (OR) and 95% confidence intervals (CIs) were computed using adjusted logistic regression models, separately for non-Hodgkin lymphoma (NHL) and Hodgkin lymphoma (HL). Specific analyses also investigated Burkitt NHL and nodular sclerosis HL, two most common histological types in children.

RESULTS

We included 305 NHL, 328 HL and 2415 controls in this study. No associations were observed with gestational age, foetal growth indicators, folic acid supplementation, factors related to maternal fertility and reproductive history, or maternal smoking during pregnancy. Maternal coffee consumption during pregnancy was associated with NHL (>2 cups/day, OR = 1.5 [95% CI: 1.1-2.1]), with a dose-response relationship; while maternal alcohol consumption was associated with Burkitt NHL (OR = 1.5 [1.1-2.2]). Paternal smoking during preconception/pregnancy was associated with NHL (OR = 1.4 [1.1-1.8]). Breastfeeding (ever/never) was not significantly associated with NHL and HL, but an inverse log-linear trend was observed with the duration of breastfeeding for NHL (p = 0.04).

CONCLUSION

Maternal coffee and alcohol consumptions during pregnancy and paternal smoking during preconception/pregnancy might increase the risk of childhood NHL. While warranting replication, these findings could help us better understand the aetiology of childhood lymphoma.

Long-Term Effects of ART on the Health of the Offspring

Assisted reproductive technologies (ART) significantly increase the chance of successful pregnancy and live birth in infertile couples. The different procedures for ART, including in vitro fertilization (IVF), intracytoplasmic sperm injection (ICSI), intrauterine insemination (IUI), and gamete intrafallopian tube transfer (GIFT), are widely used to overcome infertility-related problems. In spite of its inarguable usefulness, concerns about the health consequences of ART-conceived babies have been raised. There are reports about the association of ART with birth defects and health complications, e.g., malignancies, high blood pressure, generalized vascular functional disorders, asthma and metabolic disorders in later life. It has been suggested that hormonal treatment of the mother, and the artificial environment during the manipulation of gametes and embryos may cause genomic and epigenetic alterations and subsequent complications in the health status of ART-conceived babies. In the current study, we aimed to review the possible long-term consequences of different ART procedures on the subsequent health status of ART-conceived offspring, considering the confounding factors that might account for/contribute to the long-term consequences.

Assisted Reproductive Technology and Risk of Childhood Cancers

IMPORTANCE

The number of children born through the use of assisted reproductive technology (ART) has been increasing. These children may have higher risks for epigenetic alteration and adverse perinatal outcomes, which may be associated with childhood cancers.

OBJECTIVE

To determine the associations between different modes of conception and childhood cancers and potential mediation by preterm birth and low birth weight.

DESIGN, SETTING, AND PARTICIPANTS

This nationwide, population-based cohort study included registry data from 2 308 016 eligible parents-child triads in Taiwan from January 1, 2004, to December 31, 2017. A total of 1880 children with incident childhood cancer were identified. Data were analyzed between September 1, 2020, and June 30, 2022.

EXPOSURE

Mode of conception, defined as (1) natural conception, (2) subfertility and non-ART (ie, infertility diagnosis but no ART-facilitated conception), or (3) ART (ie, infertility diagnosis and ART-facilitated conception).

MAIN OUTCOMES AND MEASURES

Diagnosis of childhood cancer according to the International Classification of Childhood Cancers, Third Edition.

RESULTS

The mean (SD) paternal and maternal ages were 33.28 (5.07) and 30.83 (4.56) years, respectively. Of the 2 308 016 children, 52.06% were boys, 8.16% were born preterm, and 7.38% had low birth weight. During 14.9 million person-years of follow-up (median, 6 years [IQR, 3-10 years]), ART conception was associated with an increased risk of any type of childhood cancers compared with natural conception (hazard ratio, 1.58; 95% CI, 1.17-2.12) and subfertility with non-ART conception (hazard ratio, 1.42; 95% CI, 1.04-1.95). The increased cancer risk of children conceived with ART was mainly owing to leukemia and hepatic tumor. The increased cancer risk associated with ART conception was not mediated by preterm birth or low birth weight.

CONCLUSIONS AND RELEVANCE

In this cohort study, children conceived via ART had a higher risk of childhood cancers than those conceived naturally and those born to parents with an infertility diagnosis did not use ART. The increased risk could not be explained by preterm birth or low birth weight.

Maternal Medication Use and Childhood Cancer in Offspring-Systematic Review and Considerations for Researchers

Cancer is an important cause of childhood mortality, yet the etiology is largely unknown. A combination of pre- and postnatal factors is thought to be implicated, including maternal medication use. We aimed to provide: 1) a systematic review of peer-reviewed publications on associations between maternal medication use and childhood cancer, with a focus on study design and methodology; and 2) suggestions for how to increase transparency, limit potential biases, and improve comparability in studies on maternal medication use and childhood cancer. We conducted a systematic search in the PubMed, Embase, Scopus, Cochrane, and Web of Science databases to June 8, 2020. Altogether, 112 studies were identified. The reviewed studies were heterogeneous in study design, exposure, and outcome classification. In 21 studies (19%), the outcome was any childhood cancer. Of the 91 papers that reported on specific types of cancer, 62% did not report the cancer classification system. The most frequently investigated medication groups were sex hormones (46 studies, excluding fertility medications), and antiinfectives (37 studies). Suggestions for strengthening future pharmacoepidemiologic studies on maternal medication use and childhood cancer relate to choice of cancer classification system, exposure windows, and methods for identification of, and control for, potential confounders.

Etiology of Acute Leukemia: A Review

Simple Summary

Acute leukemias are some of the most common cancers affecting all age groups. Despite a significant improvement made in the treatment of acute leukemias, their cause remains unknown. A number of genetic and environmental factors for the development of acute leukemias have been proposed, but none have been proven. Undoubtedly, genetics have a major role in the development of these diseases. The effects of a variety of environmental factors, occupations and hobbies have been explored. A recent “two-hit” theory” for the development of acute lymphoblastic leukemia has been proposed. This combines genetic factors and exposure to infections for the development of this disease. Several genetic factors are suggested. Most recently, for the infection portion, exposure to a virus containing Aspergillus Flavus has been proposed. This review summarizes what is currently known about the factors that are proposed for the development of acute leukemias.

Abstract

Acute leukemias constitute some of the most common malignant disorders. Despite significant progress made in the treatment of these disorders, their etiology remains unknown. A large and diverse group of genetic and environmental variables have been proposed. The role of a variety of factors, including pre-existing and acquired genetic mutations, exposure to radiation and various chemicals during preconception, pregnancy and throughout life, have been explored. The effects of inherited genetic variations and disorders, pre-existing diseases, infectious agents, hobbies, occupations, prior treatments, and a host of other factors have been proposed, but none is universally applicable to all cases. Variation in the incidence and prognosis based on the age, sex, race, type of the disease, geographic area of residence and other factors are intriguing but remain unexplained. Advances in genomic profiling, including genome-wide gene expression, DNA copy number and single nucleotide polymorphism (SNP) genotype, may shed some light on the role of genetics in these disparities. Separate two-hit hypotheses for the development of acute myeloblastic and lymphoblastic leukemia have been proposed. The latter combines genetics and infection factors resulting in leukemogenesis. A number of pre- and post-natal environmental conditions and exposure to infections, including a mycovirus infected Aspergillus flavus, have been suggested. The exact nature, timing, sequence of the events and mechanisms resulting in the occurrence of leukemia requires further investigations. This review summarizes some of the above factors in acute lymphoblastic and myeloblastic leukemias and the direction for future research on the etiology of these disorders.

Outcome of two pairs of monozygotic twins with pleuropulmonary blastoma: case report

Background

Pleuropulmonary blastomas (PPB) are rare aggressive paediatric lung malignancies and are among the most common DICER1-related disorders: it is estimated that 75–80% of children with a PPB have the DICER1 mutation. DICER1 mutations are responsible for familial tumour susceptibility syndrome with an increased risk of tumours. In approximately 35% of families with children manifesting PPB, further malignancies may be observed. Symptoms of DICER1 syndrome may vary, even within monozygotic twins. Preventive screening of carriers with DICER1 mutations is important and follow-up is undertaken as recommended by the 2016 International PPB Register.

Case presentation

We present two pairs of monozygotic twins. In one pair of 4-year, 2-month old girls, both with DICER1 mutation, one developed PPB(II) and her identical sibling had acute transient hepatitis. In the other pair of 19-month-old female babies, one had a history of bronchopulmonary hypoplasia and developed PPB(III) without DICER1 mutation, and her identical sibling had allergic asthma. Both patients with PPB were treated with R0 resection and received 12 cycles of postoperative chemotherapy. At the most recent review, the twins had been followed up for six and eight years, respectively, and they all remained healthy. However, the height and weight of the patients with PPB were lower than those of their respective identical sister.

Conclusions

PPB is rare, especially in monozygotic twins. We emphasise the importance of genetic testing and follow-up in monozygotic twins with PPB. During the follow-up, children surviving PPB should be monitored closely for growth and development disorders which caused by chemotherapy.

The association between fertility treatments and the incidence of paediatric cancer: A systematic review and meta-analysis

BACKGROUND

It is important to explore the association between different fertility treatments and the incidence of paediatric cancer, as this will provide crucial guidance for clinical decision-making. Previous studies have explored the relationship between fertility treatments and different types of cancer in offspring, but the results are controversial.

METHOD

Two authors searched PubMed, Embase, Web of Science and Cochrane databases independently to acquire qualified studies. Then, the same authors extracted data from these studies and analysed these data using RevMan 5.3.

MAIN RESULTS

Eleven case-control studies and 16 cohort studies were included in this review and meta-analysis. The relative risk of association between in vitro fertilisation (IVF) and paediatric cancer incidence was 1.01 (95% confidence interval [CI]: 0.80-1.28) in cohort studies and 1.09 (95% CI: 0.74-1.58) in case-control studies. The relative risk of association between intracytoplasmic sperm injection (ICSI) and paediatric cancer incidence was 0.97 (95% CI: 0.80-1.17) in cohort studies. The relative risk of association between fertility drugs and paediatric cancer incidence was 1.07 (95% CI: 0.68-1.69) in cohort studies and 1.12 (95% CI: 0.90-1.41) in case-control studies. The relative risk of association between frozen embryo transfer and paediatric cancer incidence was 1.37 (95% CI: 1.04-1.81) in natural pregnancy controls and 1.28 (95% CI: 0.96-1.69) in fresh embryo transfer controls.

CONCLUSION

There is no evidence that IVF, ICSI and fertility drugs are associated with an increase in paediatric cancer incidence in offspring; however, frozen embryo transfer is associated with an increase in paediatric cancer incidence in the offspring, but this finding needs further research and attention.

Altered TH1, TH2, TH17 balance in assisted reproductive technology conceived mice

AIM AND PURPOSE

The higher prevalence rate of different diseases may accentuate the possible alteration of the immune system in individuals conceived through the assisted reproductive technologies (ART). The present study was conducted to evaluate the TH1, TH2, TH17 balance in intracytoplasmic sperm injection (ICSI) and in vitro fertilization (IVF) - conceived mice in comparison to naturally conceived offspring.

METHODS

Mice (6-8 weeks) were divided into three groups (IVF- conceived, ICSI- conceived and naturally conceived). They were subjected to subcutaneous immunization witMycobacterium bovis Bacille Calmette-Guérin (BCG). The blood samples were taken and the sera were separated. Then the spleens were surgically removed at the time the mice were sacrificed. Serum levels of IFN-γ, IL-17A and IL-4 were detected by ELISA. Then the proportion of TCD4 cells possessing the T-bet+, GATA3+, and ROR-γt + were measured using FACS caliber flow cytometer.

RESULTS

In comparison with naturally conceived mice, intracellular expression of T-bet and serum levels of IFN-γ were significantly decreased in ART- conceived mice. Moreover, ART- conceived offspring showed marked increase in IL-4 and IL-17A.

CONCLUSION

It is concluded that compared to naturally conceived male mice, ART- conceived counterparts exhibit less efficient immune responses against BCG through further promotion of humoral and inflammatory related immune response characteristics.

Cancer Risk in Children and Young Adults (Offspring) Born after Medically Assisted Reproduction: A Systematic Review and Meta-Analysis

Many studies have investigated the relationship between medically assisted reproduction (MAR) and health outcomes, particularly cancer, in the offspring. This meta-analysis investigated the association between MAR and childhood cancer. Data sources were PubMed, Scopus, and Web of Science up until June 2018. From the selected studies, we extracted the cancer risk estimates of the exposure of interest (MAR, assisted reproductive technology—ART, and in fitro fertilization—IVF). We conducted the meta-analysis using a random effects model. The outcomes of interest were childhood cancers, classified according to the international classification of childhood cancer (ICCC-3). In our meta-analysis (18 cohort and 15 case-control studies) the overall cancer risk was significantly increased in children conceived by MAR, ART, or IVF. MAR and ART significantly increased the risk for hematological tumors, hepatic tumors, and sarcomas (odds ratio (OR) 1.54; 95% CI 1.18–2.02 and OR 1.92; 95% CI 1.34–2.74, respectively). MAR increased acute myeloid leukemia risk (OR 1.41; 95% CI 1.02–1.95) and ART increased neural cancer risk (OR 1.21; 95% CI 1.01–1.46). Our results suggest an increased risk of cancer in children conceived by MAR. Further studies are needed to investigate the impact of fertility treatments, parental subfertility status, and their association on health outcomes in the offspring.

Risk of cancer in children and young adults conceived by assisted reproductive technology

STUDY QUESTION

Do children conceived by ART have an increased risk of cancer?

SUMMARY ANSWER

Overall, ART-conceived children do not appear to have an increased risk of cancer.

WHAT IS KNOWN ALREADY

Despite the increasing use of ART, i.e. IVF or ICSI worldwide, information about possible long-term health risks for children conceived by these techniques is scarce.

STUDY DESIGN, SIZE, DURATION

A nationwide historical cohort study with prospective follow-up (median 21 years), including all live-born offspring from women treated with subfertility treatments between 1980 and 2001.

PARTICIPANTS/MATERIALS, SETTING, METHODS

All offspring of a nationwide cohort of subfertile women (OMEGA study) treated in one of the 12 Dutch IVF clinics or two fertility clinics. Of 47 690 live-born children, 24 269 were ART-conceived, 13 761 naturally conceived and 9660 were conceived naturally or through fertility drugs, but not by ART. Information on the conception method of each child and potential confounders were collected through the mothers' questionnaires and medical records. Cancer incidence was ascertained through linkage with The Netherlands Cancer Registry from 1 January 1989 until 1 November 2016. Cancer risk in ART-conceived children was compared with risks in naturally conceived children from subfertile women (hazard ratios [HRs]) and with the general population (standardized incidence ratios [SIRs]).

MAIN RESULTS AND THE ROLE OF CHANCE

The median follow-up was 21 years (interquartile range (IQR): 17-25) and was shorter in ART-conceived children (20 years, IQR: 17-23) compared with naturally conceived children (24 years, IQR: 20-30). In total, 231 cancers were observed. Overall cancer risk was not increased in ART-conceived children, neither compared with naturally conceived children from subfertile women (HR: 1.00, 95% CI 0.72-1.38) nor compared with the general population (SIR = 1.11, 95% CI: 0.90-1.36). From 18 years of age onwards, the HR of cancer in ART-conceived versus naturally conceived individuals was 1.25 (95% CI: 0.73-2.13). Slightly but non-significantly increased risks were observed in children conceived by ICSI or cryopreservation (HR = 1.52, 95% CI: 0.81-2.85; 1.80, 95% CI: 0.65-4.95, respectively). Risks of lymphoblastic leukemia (HR = 2.44, 95% CI: 0.81-7.37) and melanoma (HR = 1.86, 95% CI: 0.66-5.27) were non-significantly increased for ART-conceived compared with naturally conceived children.

LIMITATIONS, REASONS FOR CAUTION

Despite the large size and long follow-up of the cohort, the number of cancers was rather small for subgroup analyses as cancer in children and young adults is rare.

WIDER IMPLICATIONS OF THE FINDINGS

Overall, ART-conceived children do not appear to have an increased cancer risk after a median follow-up of 21 years. This large study provides important results, enabling physicians to better inform couples considering ART about the long-term safety of ART for their children. However, larger studies with prolonged follow-up are needed to investigate cancer risk in adults and in children conceived by ICSI and/or from cryopreserved embryos.

STUDY FUNDING/COMPETING INTEREST(S)

This work was supported by The Dutch Cancer Society (NKI 2006-3631) which funded the OMEGA-women's cohort and Children Cancer Free (KIKA;147) which funded the OMEGA-offspring cohort. We declare no competing interests.

Parental age and the risk of childhood acute myeloid leukemia: results from the Childhood Leukemia International Consortium

BACKGROUND

Parental age has been associated with several childhood cancers, albeit the evidence is still inconsistent.

AIM

To examine the associations of parental age at birth with acute myeloid leukemia (AML) among children aged 0-14 years using individual-level data from the Childhood Leukemia International Consortium (CLIC) and non-CLIC studies.

MATERIAL/METHODS

We analyzed data of 3182 incident AML cases and 8377 controls from 17 studies [seven registry-based case-control (RCC) studies and ten questionnaire-based case-control (QCC) studies]. AML risk in association with parental age was calculated using multiple logistic regression, meta-analyses, and pooled-effect estimates. Models were stratified by age at diagnosis (infants <1 year-old vs. children 1-14 years-old) and by study design, using five-year parental age increments and controlling for sex, ethnicity, birthweight, prematurity, multiple gestation, birth order, maternal smoking and education, age at diagnosis (cases aged 1-14 years), and recruitment time period.

RESULTS

Adjusted odds ratios (ORs) and 95% confidence intervals (CIs) derived from RCC, but not from the QCC, studies showed a higher AML risk for infants of mothers ≥40-year-old (OR = 6.87; 95% CI: 2.12-22.25). There were no associations observed between any other maternal or paternal age group and AML risk for children older than one year.

CONCLUSIONS

An increased risk of infant AML with advanced maternal age was found using data from RCC, but not from QCC studies; no parental age-AML associations were observed for older children.

Cancer risk among children conceived by fertility treatment

Prior studies on the association between fertility treatment and childhood cancer risk have generated inconsistent results. We performed a systematic review and meta-analysis of observation studies to summarize the evidence regarding the relation of fertility treatment with childhood cancer risk. A systematic literature search of several databases was conducted through April 2018 to identify relevant studies. The outcomes of interest included overall cancer, haematological malignancies, neural tumours, other solid tumours, and eight specific cancers. The overall risk estimates and corresponding 95% confidence intervals (CIs) were pooled using random-effects meta-analysis. Sixteen cohort and thirteen case-control studies were included. Results showed that children conceived by fertility treatment had significantly higher risk for developing overall cancer (relative risk [RR]: 1.16, 95% CI: 1.01, 1.32), haematological malignancies (RR: 1.39, 95% CI: 1.21, 1.60) and other solid tumours (RR: 1.57, 95% CI: 1.14, 2.16). For specific cancers, fertility treatment was associated with a significantly increased risk of leukaemia (RR: 1.31, 95% CI: 1.09, 1.57) and hepatic tumours (RR: 2.26, 95% CI: 1.32, 3.85). Sensitivity analysis validated evidence of the robustness of the findings. The results may demonstrate a possible association between fertility treatment and an increased risk of cancer among the offspring. However, the findings cannot say whether this increased risk is due to the subfertility itself or to the fertility treatment. Further research is needed to address the underlying mechanisms.

Literature review on cancer risk in children born after fertility treatment suggests increased risk of haematological cancers

Medically assisted fertility treatment, including assisted reproductive technology (ART), is increasingly being used and the subsequent child health outcomes are of interest. Some studies have suggested an elevated risk of somatic morbidity, while others have reported an elevated cancer risk. This review summarises the literature on fertility treatments and childhood cancer, based on 23 cohort and case-control studies.

CONCLUSION

The findings varied, but reassuring results on overall childhood cancer and fertility treatment were observed. However, some studies suggested an elevated risk of haematological cancers. More large population-based studies are needed, and the growing population of ART children should be monitored.

Maternal fetal loss history and increased acute leukemia subtype risk in subsequent offspring: a systematic review and meta-analysis

PURPOSE

History of fetal loss including miscarriage and stillbirth has been inconsistently associated with childhood (0-14 years) leukemia in subsequent offspring. A quantitative synthesis of the inconclusive literature by leukemia subtype was therefore conducted.

METHODS

Eligible studies (N = 32) were identified through the screening of over 3500 publications. Random-effects meta-analyses were conducted on the association of miscarriage/stillbirth history with overall (AL; 18,868 cases/35,685 controls), acute lymphoblastic (ALL; 16,150 cases/38,655 controls), and myeloid (AML; 3042 cases/32,997 controls) leukemia. Sensitivity and subgroup analyses by age and ALL subtype, as well as meta-regression were undertaken.

RESULTS

Fetal loss history was associated with increased AL risk [Odds Ratio (OR) 1.10, 95% Confidence Intervals (CI) 1.04-1.18]. The positive association was seen for ALL (OR 1.12, 95%CI 1.05-1.19) and for AML (OR 1.13, 95%CI 0.91-1.41); for the latter the OR increased in sensitivity analyses. Notably, stillbirth history was significantly linked to ALL risk (OR 1.33, 95%CI 1.02-1.74), but not AML. By contrast, the association of ALL and AML with previous miscarriage reached marginal significance. The association of miscarriage history was strongest in infant ALL (OR 2.34, 95%CI 1.19-4.60).

CONCLUSIONS

In this meta-analysis involving >50,000 children, we found noteworthy associations by indices of fetal loss, age at diagnosis, and leukemia type; namely, of stillbirth with ALL and miscarriage history with infant ALL. Elucidation of plausible underlying mechanisms may provide insight into leukemia pathogenesis and indicate monitoring interventions prior to and during pregnancy.

Possible risk for cancer among children born following assisted reproductive technology in Israel

BACKGROUND

Among children conceived by assisted reproductive technology (ART), increased risk of adverse birth outcomes has been observed, including multiple births, preterm births, and congenital malformations. Regarding cancer among ART-conceived children, findings are discrepant.

METHODS

This is a historical cohort of 9,042 ART-conceived children and 211,763 spontaneously conceived (SC) children born from 1997 through 2004. The median duration of follow-up was 10.6 years (interquartile range 9.0-12.3) in the ART group and 9.3 years (interquartile range 8.0-10.6) in the SC group. The cohort database was linked with the Israel National Cancer Registry updated until December 31, 2011 using each child's personal identification number.

RESULTS

Twenty-one cases of cancer were identified in the ART group (2.2 per 10,000 person-years), as compared to 361 cancer cases in the SC group (1.8 per 10,000 person-years). The relative risk (RR) for overall cancer in the ART group compared to the SC group adjusted for maternal characteristics was 1.18 (95% confidence interval [CI] 0.80-1.75). ART children had a significantly increased risk for specific cancers, although based on small number of cases, including two cases of retinoblastoma (RR 6.18, 95% CI 1.22-31.2), as well as four cases of renal tumors (RR 3.25, 95% CI 1.67-6.32).

CONCLUSION

A statistically significant increased risk for two pediatric cancers was found. However, for overall types of cancer the risk estimate was elevated but not statistically significant. Further studies with larger sample size and longer follow-up time are warranted in order to either confirm or refute these findings.

Association of maternal and index child's diet with subsequent leukemia risk: A systematic review and meta analysis

BACKGROUND

Exploring the effect of maternal and/or childhood diet on offspring leukemogenesis is challenging, given differences in food group categories, their potentially variable impact depending on time window of exposure and the multiple leukemia subtypes. We opted to quantitatively synthesize published data on the association of maternal/child diet with leukemia risk.

METHODS

Medline was searched until June 30th, 2016 for eligible articles on the association of childhood leukemia with consumption of (i) food groups, excluding alcoholic and non-alcoholic beverages, and (ii) specific dietary supplements before/during index pregnancy and childhood.

RESULTS

Eighteen studies of case-control design (N=11,720 cases/18,721 controls) were included, of which nine assessed maternal dietary components, five index child's and four both, mainly focusing on acute lymphoblastic leukemia (ALL). Statistically significant inverse estimates for ALL were found (2 studies, 413 cases, 490 controls) for fruit (OR: 0.81, 95% CI: 0.67, 0.99); vegetables (OR: 0.51, 95% CI: 0.28, 0.94); legumes (OR: 0.76, 95% CI: 0.62, 0.94); fish (OR: 0.27, 95% CI: 0.14, 0.53, among the 0-4year old; 2 studies 215 cases, 215 controls); preconception folic acid supplementation (OR: 0.69, 95%CI: 0.50-0.95; published meta analysis plus 2 studies, 3511 cases, 6816 controls); and use of vitamins during pregnancy (OR: 0.81, 95%CI: 0.74-0.88; published meta analysis plus one study, 5967 cases, 8876 controls). The associations (2 studies) of the remaining food groups and maternal dietary supplements consumption during pregnancy as well as of childhood diet and supplements intake (2-4 studies) were non significant.

CONCLUSIONS

Maternal consumption of specific food groups comprising"healthy" items of the Mediterranean diet, preconception use of folic acid and intake of vitamins during pregnancy were associated with decreased ALL risk. Further research is needed, however preferably with homogeneous dietary information and data on immunophenotypic/cytogenetic subtypes to also explore the interaction of specific macro- and micronutrients intake with gene polymorphisms.

Fertility treatments and pediatric neoplasms of the offspring: results of a population-based cohort with a median follow-up of 10 years

OBJECTIVE

Studies have questioned the long-term health effects of offspring conceived after fertility treatments.

METHODS

We aimed to evaluate whether an association exists between mode of conception (in vitro fertilization, ovulation induction, or spontaneous pregnancy) and neoplasm risk (both benign and malignant tumors) among the offspring; we observed the offspring for up to 18 years.

STUDY DESIGN

A population-based cohort analysis was performed that compared the risk for neoplasms among children (up to the age of 18 years) based on mode of conception. Neoplasm diagnoses were based on hospital records of the same single tertiary center in the region. All singletons born during from 1991-2013 and discharged alive were included in the study. Offspring with congenital malformations were excluded from the analysis. Kaplan-Meier survival curves were constructed to compare cumulative neoplasms incidence; multivariable survival analyses were used to control for confounders that included gestational age, pregnancy complications, and maternal factors.

RESULTS

During the study period, 242,187 newborn infants met the inclusion criteria: 2603 (1.1%) were conceived after in vitro fertilization; 1721 (0.7%) were conceived after ovulation induction treatments, and 237,863 (98.3%) were conceived spontaneously. During the follow-up period (median, 10.55 years), 1498 neoplasms(0.6%) were diagnosed. Incidence density rate for neoplasms was higher among children conceived either after in vitro fertilization (1.5/1000 person years) or ovulation induction treatments (1.0/1000 person years), as compared with naturally conceived children (0.59/1000 person years; Kaplan-Meier log rank, P<.001). The association between in vitro fertilization and total pediatric neoplasms and the association between any fertility treatments and malignancies remained significant; we controlled for confounders such as gestational diabetes mellitus, hypertensive disorders, preterm birth, and maternal age (adjusted hazard ratio, 2.48; 95% confidence interval, 1.71-3.50; and adjusted hazard ratio, 1.96; 95% confidence interval, 1.14-3.36, for all neoplasms and all malignancies, respectively).

CONCLUSION

Children conceived after fertility treatments are at an increased risk for pediatric neoplasms.

Mechanisms of epigenetic remodelling during preimplantation development

Epigenetics involves mechanisms independent of modifications in the DNA sequence that result in changes in gene expression and are maintained through cell divisions. Because all cells in the organism contain the same genetic blueprint, epigenetics allows for cells to assume different phenotypes and maintain them upon cell replication. As such, during the life cycle, there are moments in which the epigenetic information needs to be reset for the initiation of a new organism. In mammals, the resetting of epigenetic marks occurs at two different moments, which both happen to be during gestation, and include primordial germ cells (PGCs) and early preimplantation embryos. Because epigenetic information is reversible and sensitive to environmental changes, it is probably no coincidence that both these extensive periods of epigenetic remodelling happen in the female reproductive tract, under a finely controlled maternal environment. It is becoming evident that perturbations during the extensive epigenetic remodelling in PGCs and embryos can lead to permanent and inheritable changes to the epigenome that can result in long-term changes to the offspring derived from them, as indicated by the Developmental Origins of Health and Disease (DOHaD) hypothesis and recent demonstration of inter- and trans-generational epigenetic alterations. In this context, an understanding of the mechanisms of epigenetic remodelling during early embryo development is important to assess the potential for gametic epigenetic mutations to contribute to the offspring and for new epimutations to be established during embryo manipulations that could affect a large number of cells in the offspring. It is of particular interest to understand whether and how epigenetic information can be passed on from the gametes to the embryo or offspring, and whether abnormalities in this process could lead to transgenerationally inheritable phenotypes. The aim of this review is to highlight recent progress made in understanding the nature and mechanisms of epigenetic remodelling that ensue after fertilisation.

Environmental, maternal, and reproductive risk factors for childhood acute lymphoblastic leukemia in Egypt: a case-control study

BACKGROUND

Acute lymphocytic leukemia (ALL) is the most common pediatric cancer. The exact cause is not known in most cases, but past epidemiological research has suggested a number of potential risk factors. This study evaluated associations between environmental and parental factors and the risk for ALL in Egyptian children to gain insight into risk factors in this developing country.

METHODS

We conducted a case-control design from May 2009 to February 2012. Cases were recruited from Children's Cancer Hospital, Egypt (CCHE). Healthy controls were randomly selected from the general population to frequency-match the cumulative group of cases by sex, age groups (<1; 1 - 5; >5 - 10; >10 years) and region of residence (Cairo metropolitan region, Nile Delta region (North), and Upper Egypt (South)). Mothers provided answers to an administered questionnaire about their environmental exposures and health history including those of the father. Odds ratios (ORs) and 95 % confidence intervals (CI) were calculated using logistic regression with adjustment for covariates.

RESULTS

Two hundred ninety nine ALL cases and 351 population-based controls frequency-matched for age group, gender and location were recruited. The risk of ALL was increased with the mother's use of medications for ovulation induction (ORadj = 2.5, 95 % CI =1.2 -5.1) and to a lesser extend with her age (ORadj = 1.8, 95 % CI = 1.1 - 2.8, for mothers ≥ 30 years old). Delivering the child by Cesarean section, was also associated with increased risk (ORadj = 2.01, 95 % CI =1.24-2.81).

CONCLUSIONS

In Egypt, the risk for childhood ALL appears to be associated with older maternal age, and certain maternal reproductive factors.

Risk of Cancer in Children Conceived by Assisted Reproductive Technology

BACKGROUND AND OBJECTIVE

An increasing number of children are born after assisted reproductive technology (ART), and monitoring their long-term health effects is of interest. This study compares cancer risk in children conceived by ART to that in children conceived without.

METHODS

The Medical Birth Registry of Norway contains individual information on all children born in Norway (including information of ART conceptions). All children born between 1984 and 2011 constituted the study cohort, and cancer data were obtained from the Cancer Registry of Norway. Follow-up started at date of birth and ended on the date of the first cancer diagnosis, death, emigration, or December 31, 2011. A Cox proportional hazards model was used to calculate hazard ratios (HR) and 95% confidence intervals (CI) of overall cancer risk between children conceived by ART and those not. Cancer risk was also assessed separately for all childhood cancer types.

RESULTS

The study cohort comprised 1 628 658 children, of which 25 782 were conceived by ART. Of the total 4554 cancers, 51 occurred in ART-conceived children. Risk of overall cancer was not significantly elevated (HR 1.21; 95% CI 0.90-1.63). However, increased risk of leukemia was observed for children conceived by ART compared with those who were not (HR 1.67; 95% CI 1.02-2.73). Elevated risk of Hodgkin's lymphoma was also found for ART-conceived children (HR 3.63; 95% CI 1.12-11.72), although this was based on small numbers.

CONCLUSIONS

This population-based cohort study found elevated risks of leukemia and Hodgkin's lymphoma in children conceived by ART.

History of Maternal Fetal Loss and Childhood Leukaemia Risk in Subsequent Offspring: Differentials by Miscarriage or Stillbirth History and Disease Subtype

BACKGROUND

Despite the putative intrauterine origins of childhood (0-14 years) leukaemia, it is complex to assess the impact of perinatal factors on disease onset. Results on the association of maternal history of fetal loss (miscarriage/stillbirth) with specific disease subtypes in the subsequent offspring are in conflict. We sought to investigate whether miscarriage and stillbirth may have different impacts on the risk of acute lymphoblastic leukaemia (ALL) and of its main immunophenotypes (B-cell and T-cell ALL), as contrasted to acute myeloid leukaemia (AML).

METHODS

One thousand ninety-nine ALL incidents (957 B-ALL) and 131 AML cases along with 1:1 age and gender-matched controls derived from the Nationwide Registry for Childhood Hematological Malignancies and Brain Tumors (1996-2013) were studied. Multivariable regression models were used to assess the roles of previous miscarriage(s) and stillbirth(s) on ALL (overall, B-, T-ALL) and AML, controlling for potential confounders.

RESULTS

Statistically significant exposure and disease subtype-specific associations of previous miscarriage(s) exclusively with AML [odds ratio (OR) 1.67, 95% confidence interval (CI) 1.00, 2.81] and stillbirth(s) with ALL [OR 4.82, 95% CI 1.63, 14.24] and B-ALL particularly, emerged.

CONCLUSION

Differential pathophysiological pathways pertaining to genetic polymorphisms or cytogenetic aberrations are likely to create hostile environments leading either to fetal loss or the development of specific leukaemia subtypes in subsequent offspring, notably distinct associations of maternal miscarriage history confined to AML and stillbirth history confined to ALL (specifically B-ALL). If confirmed and further supported by studies revealing underlying mechanisms, these results may shed light on the divergent leukemogenesis processes.

Effect of Xianziyizhen Recipe Capsule on PGI2-PPARδ Signaling Pathway in Embryo Implantation Dysfunction Mice

PROBLEM

We investigated the effect of Xianziyizhen recipe capsule (XRC), a kidney-tonifying herb, on the PGI2-PPARδ signaling pathway at the maternal-fetal interface in embryo implantation dysfunction (EID) mice.

METHOD OF STUDY

Intragastric administration of Progynova (estradiol) or XRC was performed in EID mouse model, following experimental induction of kidney deficiency by co-treatment with chemotherapy drug hydroxyurea and antiprogesterone mifepristone. The PPARδ and IL-11 mRNA expression in endometrium were detected by real-time relative reverse transcription-polymerase chain reaction (RT-PCR). Further, the protein expression of COX-2, PGI2, MMP-9, and TIMP-3 was detected in endometrial glandular epithelium and in stromal cells by immunohistochemical (IHC) assay.

RESULTS

The results showed that hydroxyurea and mifepristone-induced EID were associated with significantly lower PPARδ and IL-11 mRNA levels in endometrium and reduced COX-2, PGI2, MMP-9, and TIMP-3 levels in endometrial glandular epithelium, compared with normal controls. However, XRC and Progynova treatment reversed these effects, leading to significant increases in PPARδ and IL-11 mRNA expression, and COX-2, PGI2, MMP-9 and TIMP-3 protein levels, when compared with the levels observed in EID mice.

CONCLUSION

These results strongly suggested that XRC is beneficial in EID treatment and that XRC may mediate its effects through regulation of the PGI2-PPARδ signaling pathway.

Assisted reproductive technology and somatic morbidity in childhood: a systematic review

OBJECTIVE

To assess whether children conceived by assisted reproductive technology are at increased risk of somatic morbidity in childhood compared with spontaneously conceived children.

DESIGN

Systematic review.

SETTING

None.

PATIENT(S)

Children conceived by assisted reproductive technology and reference groups of spontaneously conceived children or children from the background population.

INTERVENTION(S)

Medline/Pubmed, Embase, and the Cochrane Library were searched as well as reference lists of the retrieved relevant studies. Only cohort studies and case-control studies were included. All studies were scored using the Newcastle-Ottawa scale to assess study quality and the risk of bias in the individual studies.

MAIN OUTCOME MEASURE(S)

Postneonatal somatic diseases, health care use, chronic illnesses (unspecified), surgery, use of medication, and mortality.

RESULT(S)

Thirty-eight studies were included. Results indicated that children conceived by assisted reproductive technology may be at increased risk of unspecified infectious and parasitic diseases, asthma, genitourinary diseases, epilepsy or convulsions, and longer hospitalizations. However, several results in individual studies were not statistically significant and some inconsistency existed between study results. No differences between groups were found regarding hospital admission, outpatient visits, or use of medication. Results regarding mortality, unspecified cancer, pneumonia, allergy, respiratory, and gastrointestinal diseases were contradictory. When considering only the 13 studies allocated the highest score on the Newcastle-Ottawa scale, similar results were found.

CONCLUSION(S)

Children conceived by assisted reproductive technology may be at increased risk of somatic morbidity in childhood compared with spontaneously conceived children, although some inconsistency exists between study results.

Descriptive Epidemiology in Mexican children with cancer under an open national public health insurance program

Background

All the children registered at the National Council for the Prevention and Treatment of Childhood Cancer were analyzed. The rationale for this Federal Government Council is to financially support the treatment of all children registered into this system. All patients are within a network of 55 public certified hospitals nationwide.

Methods

In the current study, data from 2007 to 2012 are presented for all patients (0–18 years) with a pathological diagnosis of leukemia, lymphoma and solid tumors. The parameters analyzed were prevalence, incidence, mortality, and abandonment rate.

Results

A diagnosis of cancer was documented in 14,178 children. The incidence was of 156.9/million/year (2012). The median age was 4.9. The most common childhood cancer is leukemia, which occurs in 49.8% of patients (2007–2012); and has an incidence rate of 78.1/million/year (2012). The national mortality rate was 5.3/100,000 in 2012, however in the group between 15 to 18 years it reaches a level of 8.6.

Conclusions

The study demonstrates that there is a high incidence of childhood cancer in Mexico. In particular, the results reveal an elevated incidence and prevalence of leukemia especially from 0 to 4 years. Only 4.7% of these patients abandoned treatment. The clinical outcome for all of the children studied improved since the establishment of this national program.

Maternal use of fertility drugs and risk of cancer in children--a nationwide population-based cohort study in Denmark

Large population-based studies are needed to examine the effect of maternal use of fertility drugs on the risk of cancer in children, while taking into account the effect of the underlying infertility. A cohort of 123,322 children born in Denmark between 1964 and 2006 to 68,255 women who had been evaluated for infertility was established. We used a case-cohort design and calculated hazard ratios (HRs) for cancer in childhood (0-19 years) and in young adulthood (20-29 years) associated with maternal use of six groups of fertility drugs (clomiphene, gonadotropins [i.e., human menopausal gonadotropins and follicle-stimulating hormone], gonadotropin-releasing hormone analogs, human chorionic gonadotropins, progesterone and other fertility drugs). We found no statistically significant association between maternal use of fertility drugs and risk for overall cancer in childhood or young adulthood. However, with regard to specific cancers in childhood, our results showed that maternal use of progesterone before childbirth markedly increased the risks of their offspring for acute lymphocytic leukemia (any use: HR, 4.95; 95% CI, 1.69-14.54; ≥ three cycles of use: HR, 9.96; 95% CI, 2.63-37.77) and for sympathetic nervous system tumors (any use: HR, 5.79; 95% CI, 1.23-27.24; ≥ three cycles of use: HR, 8.51; 95% CI, 1.72-42.19). These findings show that maternal use of progesterone may increase the risk for specific cancers in the offspring. Additional large epidemiological studies are urgently needed to confirm our finding.

The risk of neurodisability and other long-term outcomes for infants born following ART

Children born after assisted reproductive technologies (ART) have an increased morbidity. The risk of developing cerebral palsy is nearly doubled and the risk of developing epilepsy is also higher. Behavioural problems including attention deficit/hyperactivity disorder may be more common in children born following ART than among naturally conceived children but the finding is uncertain. Data on autism are difficult to interpret. There may exist a small increase in the incidence of childhood cancer and there is greater evidence of an elevated risk of asthma. To some extent, these risks are mediated by neonatal complications including prematurity and low birth weight but some effects such as cerebral palsy are likely to be linked to the increased rate of multiple births after ART. Many of the neonatal complications after ART are most likely linked to parental subfertility and are less an effect of the ART technology. The possibility exists that imprinting errors, associated with subfertility and/or ART, may result in long-term morbidity.

Cancer in children and young adults born after assisted reproductive technology: a Nordic cohort study from the Committee of Nordic ART and Safety (CoNARTaS)

STUDY QUESTION

Do children and young adults born after assisted reproductive technology (ART) have an increased risk of cancer?

SUMMARY ANSWER

Children born after ART showed no overall increase in the rate of cancer when compared with children born as a result of spontaneous conception.

WHAT IS KNOWN ALREADY

Children born after ART have more adverse perinatal outcomes, i.e. preterm births, low birthweights and birth defects. Previous studies have shown divergent results regarding the risk of cancer among children born after ART.

STUDY DESIGN, SIZE, DURATION

A retrospective Nordic population-based cohort study was performed, comprising all children born after ART in Sweden, Denmark, Finland and Norway between 1982 and 2007. The mean (±standard deviation) follow-up time was 9.5 (4.8) years.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Children born after ART (n = 91 796) were compared with a control group of children born after spontaneous conception. This control group was almost 4-fold the size of the ART group (n = 358 419) and matched for parity, year of birth and country. Data on perinatal outcomes and cancer were obtained from the National Medical Birth Registries, the Cancer Registries, the Patient Registries and the Cause of Death Registries. The cancer diagnoses were divided into 12 main groups. Hazard ratios (HRs) and adjusted HR were calculated. Adjustments were carried out for country, maternal age, parity, sex, gestational age and birth defects.

MAIN RESULTS AND THE ROLE OF CHANCE

There was no significant increase in overall cancer rates among children born after ART when compared with children born after spontaneous conception (adjusted HR 1.08; 95% CI 0.91-1.27). Cancer, of any form, was found among 181 children born after ART (2.0/1000 children, 21.0/100 000 person-years) compared with 638 children born after spontaneous conception (1.8/1000 children, 18.8/100 000 person-years). Leukaemia was the most common type of cancer (n = 278, 0.62/1000 children) but no significantly increased incidence was found among children born after ART. An increased risk was observed for 2 of 12 cancer groups. They were central nervous system tumours (adjusted HR 1.44; 95% CI 1.01-2.05) and malignant epithelial neoplasms (adjusted HR 2.03; 95% CI 1.06-3.89); the absolute risks were 0.46/1000 and 0.15/1000 children, respectively, corresponding to an absolute increased risk of 0.14/1000 and 0.08/1000 children, respectively.

LIMITATIONS, REASONS FOR CAUTION

As this is an observational study, the main limitation is the fact that it is not possible to adjust for all potential confounders. We were not able to control for confounders such as socio-economic status and perinatal factors, such as Apgar score, which other studies have suggested affect cancer rates.

WIDER IMPLICATIONS OF THE FINDINGS

The results of this large population-based cohort study are in agreement with most previously published studies. The main findings are reassuring for couples undergoing ART, children born after ART and clinicians working with ART.

STUDY FUNDING/COMPETING INTERESTS

No conflict of interest was reported. The study was supported by grants from The European Society for Human Reproduction and Embryology (ESHRE), Sahlgrenska University Hospital, Gothenburg, Sweden, the University of Copenhagen, Denmark, the Danish Agency of Science, Technology and Innovation and the Nordic Federation of Societies of Obstetrics and Gynecology (NFOG).

Nordic databases to evaluate medications in pregnancy

The objective of this review is to describe the possibilities to assess drugs used in pregnancy by means of the Nordic health registers. The Nordic countries comprise five countries: Denmark, Finland, Iceland, Norway and Sweden and have a total population of 25 million. All five countries have in their national health registers for many years recorded information concerning all births, cancer diagnoses, hospital contacts, causes of death and dispensed drugs. The registers can be used for studying drugs dispensed during pregnancy and though most previous studies focused on risks of congenital abnormalities, other health consequences of maternal medication can also be assessed.

IVF and breast cancer: a systematic review and meta-analysis

BACKGROUND

The effects of controlled ovarian hyperstimulation (COH) for IVF in terms of breast cancer risk remain controversial, despite the hormone-dependent nature of the latter.

METHODS

Eligible studies up to 15 February 2013 were identified and pooled effect estimates for relative risk (RR) were calculated separately for the investigations using the general population and those using infertile women, as a reference group. Fixed- or random-effects models were implemented and subgroup analyses were performed, as appropriate.

RESULTS

Eight cohort studies were synthesized, yielding a total cohort size of 1,554,332 women among whom 14,961 incident breast cancer cases occurred, encompassing 576 incident breast cancer cases among women exposed to IVF. No significant association between IVF and breast cancer was observed either in the group of studies treating the general population (RR = 0.91, 95% confidence interval (CI): 0.74-1.11) or infertile women (RR = 1.02, 95% CI: 0.88-1.18), as a reference group. Of note were the marginal associations, protective for pregnant and/or parous women after IVF (pooled effect estimate = 0.86, 95% CI: 0.73-1.01) and adverse for women <30 years at first IVF treatment (pooled effect estimate = 1.64, 95% CI: 0.96-2.80).

CONCLUSIONS

At present, COH for IVF does not seem to impart increased breast cancer risk. Longer follow-up periods, comparisons versus infertile women, subgroup analyses aiming to trace vulnerable subgroups, adjustment for various confounders and larger informative data sets are needed before conclusive statements for the safety of the procedure are reached.

Childhood leukemia and lymphoma: time trends and factors affecting survival in five Southern and Eastern European Cancer Registries

PURPOSE

Within Europe, incidence and mortality rates of childhood leukemia and lymphoma are rather heterogeneous. The present study comprising data from five Southern and Eastern European Cancer Registries aims to compare time trends and examine whether sociodemographic variables, clinical parameters, and proxies of efficient care affect survival.

METHODS

Data spanning 1996-2010 were obtained for a total of 3,041 newly diagnosed childhood leukemia and 1,183 lymphoma cases reported by the Greek Nationwide Registry for Childhood Hematological Malignancies, Bulgarian National Cancer Registry, Moscow Region and Turkey (Antalya and Izmir) Cancer Registries. Poisson modeling for the evaluation of time trends and multivariate Cox regression analysis for the assessment of prognostic factors were performed.

RESULTS

The incidence of leukemia was increasing in all cases, with Bulgaria and Greece presenting statistically significant annual changes (+3.5, and +1.7 %, respectively), followed by marginally increasing trends in Izmir and Moscow; by contrast, there was a remarkable, statistically significant, decreasing mortality trend for leukemia. Rates for lymphoma remained flat. Greece experienced almost twofold better survival rates for both leukemia and lymphoma, probably due to its higher socioeconomic status during the study period. Overall, patients with leukemia living in rural areas had a 28 % lower prognosis (RR: 1.28, 95 % CI 1.03-1.59), pointing to effects of remoteness, when the most privileged country (Greece) was excluded from the analysis.

CONCLUSIONS

The favorable mortality trends highlight the progress in Southern-Eastern European countries along their trajectory to converge with Northern-Western EU counterpart states. Socioeconomic status may act as a multipotent factor underlying the study findings.

Long-term follow-up of children conceived through assisted reproductive technology

Children conceived via assisted reproductive technologies (ART) are nowadays a substantial proportion of the population. It is important to follow up these children and evaluate whether they have elevated health risks compared to naturally conceived (NC) children. In recent years there has been a lot of work in this field. This review will summarize what is known about the health of ART-conceived children, encompassing neonatal outcomes, birth defects, growth and gonadal developments, physical health, neurological and neurodevelopmental outcomes, psychosocial developments, risk for cancer, and epigenetic abnormalities. Most of the children conceived after ART are normal. However, there is increasing evidence that ART-conceived children are at higher risk of poor perinatal outcome, birth defects, and epigenetic disorders, and the mechanism(s) leading to these changes have not been elucidated. Continuous follow-up of children after ART is of great importance as they progress through adolescence into adulthood, and new ART techniques are constantly being introduced.

Fertility treatment and childhood cancer risk: a systematic meta-analysis

OBJECTIVE

To clarify the association between fertility treatment and the risk for cancer in children.

DESIGN

Meta-analysis.

SETTING

None.

PATIENT(S)

Twenty-five cohort and case-control studies involving children born after fertility treatment as the exposure of interest and cancer as the outcome.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Medline was searched through September 2012 to identify relevant studies. The study-specific estimates for each cancer outcome were combined into a pooled relative risk (RR) with 95% confidence interval (CI) by a meta-analytic approach.

RESULT(S)

We found that children born after fertility treatment were at increased risk for all cancers (RR = 1.33; 95% CI, 1.08-1.63) and for hematological cancers (RR = 1.59; 95% CI, 1.32-1.91), central nervous system/neural cancers (RR = 1.88; 95% CI, 1.02-3.46), and other solid cancers (RR = 2.19; 95% CI, 1.26-3.80). For specific cancer types, we found increased risks for leukemias (RR = 1.65; 95% CI, 1.35-2.01), neuroblastomas (RR = 4.04; 95% CI, 1.24-13.18), and retinoblastomas (RR = 1.62; 95% CI, 1.12-2.35) associated with fertility treatment.

CONCLUSION(S)

The results of the largest meta-analysis on this topic to date indicate an association between fertility treatment and cancer in offspring. However, our results do not rule out that factors related to underlying subfertility, rather than the procedure itself, are the most important predisposing factors for childhood cancer.

ART and health: clinical outcomes and insights on molecular mechanisms from rodent studies

Since the birth of the first IVF-conceived child in 1978, the use of assisted reproductive technologies (ART) has grown dramatically, contributing to the successful birth of 5 million individuals worldwide. However, there are several reported associations of ART with pregnancy complications, such as low birthweight (LBW), preterm birth, birth defects, epigenetic disorders, cancer and poor metabolic health. Whether this is attributed to ART procedures or to the subset of the population seeking ART remains a controversy, but the most relevant question today concerns the potential long-term implications of assisted conception. Recent evidence has emerged suggesting that ART-conceived children have distinct metabolic profiles that may predispose to cardiovascular pathologies in adulthood. Because the eldest IVF individuals are still too young to exhibit components of chronic middle-aged syndromes, the use of animal models has become particularly useful in describing the effects of unusual or stressful preimplantation experiences on adult fitness. Elucidating the molecular mechanisms by which embryos integrate environmental signals into development and metabolic gene expression programs will be essential for optimizing ART procedures such as in vitro culture conditions, embryo selection and transfer. In the future, additional animal studies to identify mechanisms underlying unfavorable ART outcomes, as well as more epidemiological reviews to monitor the long-term health of ART children are required, given that ART procedures have become routine medical practice.

Fertility treatments and childhood acute leukemia

SUMMARY Fertility treatments are enjoying increasing use around the world. As they intervene at such a sensitive time at the start of development, the effects of these treatments on children have been closely scrutinized, with generally reassuring results. Reports of a possible slightly increased risk of acute leukemia (AL) in children born after assisted reproductive technology have been investigated by a series of studies. Research in this field could provide clues not only to the effects of different treatments, but perhaps also to the etiology of AL, which remains largely enigmatic. This special report investigates the evidence of a possible association specifically between childhood AL and assisted reproductive technology, and offers an outlook for the direction of this important field in the future.

Increased risk for cancer among offspring of women with fertility problems

Some studies have indicated that children born after fertility treatment have a potential risk for cancer, but the results are inconsistent. Furthermore, any negative effects of fertility treatment might be due to the underlying infertility rather than to the procedure itself. In the largest cohort study to date with information on fertility, we examined whether the offspring of women with fertility problems had a higher risk for cancer than offspring of women without fertility problems. The study cohort consisted of 2,830,054 offspring born in Denmark between 1964 and 2006. Of these, 125,844 were offspring of women evaluated for infertility. Cox regression models were used to estimate the possible effect of being the offspring of a woman evaluated for infertility on the risk for cancer. Analyses were performed separately for cancer during childhood (0-19 years) and cancer in young adulthood (>20 years). We found that offspring born to women with fertility problems had higher overall risks for cancer in childhood (hazard ratio (HR), 1.18; 95% confidence interval (CI), 1.05-1.32) and in young adulthood (HR, 1.22; 95% CI, 1.04-1.43) than offspring of women without fertility problems. Offspring of women with fertility problems had significantly increased risks for leukemia in childhood (HR, 1.30; 95% CI, 1.06-1.60) and for cancer of the endocrine glands in young adulthood (HR, 2.67; 95% CI, 1.35-5.29). These findings suggest that offspring born to mothers with fertility problems are at increased risk for cancer in both childhood and young adulthood. If real, our findings of an ∼18% overall increase in risk for cancer in childhood and an ∼22% overall increase in risk for cancer in young adulthood would mean about four additional cases of childhood cancer and about nine additional cases of cancer in young adults per 100,000 exposed offspring.

The Childhood Leukemia International Consortium

BACKGROUND

Acute leukemia is the most common cancer in children under 15 years of age; 80% are acute lymphoblastic leukemia (ALL) and 17% are acute myeloid leukemia (AML). Childhood leukemia shows further diversity based on cytogenetic and molecular characteristics, which may relate to distinct etiologies. Case-control studies conducted worldwide, particularly of ALL, have collected a wealth of data on potential risk factors and in some studies, biospecimens. There is growing evidence for the role of infectious/immunologic factors, fetal growth, and several environmental factors in the etiology of childhood ALL. The risk of childhood leukemia, like other complex diseases, is likely to be influenced both by independent and interactive effects of genes and environmental exposures. While some studies have analyzed the role of genetic variants, few have been sufficiently powered to investigate gene-environment interactions.

OBJECTIVES

The Childhood Leukemia International Consortium (CLIC) was established in 2007 to promote investigations of rarer exposures, gene-environment interactions and subtype-specific associations through the pooling of data from independent studies.

METHODS

By September 2012, CLIC included 22 studies (recruitment period: 1962-present) from 12 countries, totaling approximately 31000 cases and 50000 controls. Of these, 19 case-control studies have collected detailed epidemiologic data, and DNA samples have been collected from children and child-parent trios in 15 and 13 of these studies, respectively. Two registry-based studies and one study comprising hospital records routinely obtained at birth and/or diagnosis have limited interview data or biospecimens.

CONCLUSIONS

CLIC provides a unique opportunity to fill gaps in knowledge about the role of environmental and genetic risk factors, critical windows of exposure, the effects of gene-environment interactions and associations among specific leukemia subtypes in different ethnic groups.

Fertility treatments, congenital malformations, fetal loss, and childhood acute leukemia: the ESCALE study (SFCE)

BACKGROUND

This study investigated the relationships between childhood acute leukemia (AL) and selective maternal and birth characteristics, including congenital malformations and the use of fertility treatment, for which the literature remains scarce.

PROCEDURE

The national registry-based case-control study ESCALE was carried out in France in 2003-2004. Population controls were frequency matched with cases on age and gender. Data were obtained from structured telephone questionnaires. Odds ratios (OR) and their 95% confidence intervals were estimated using unconditional regression models adjusted for potential confounders.

RESULTS

In all, 764 cases of AL (648 lymphoblastic AL (acute lymphoblastic leukemia, ALL) and 101 myeloblastic AL) and 1,681 controls were included. The AL cases' mothers reported congenital malformations more frequently than the controls' mothers (OR = 1.5 [1.0-2.4]). ALL was significantly associated with the use of fertility treatment for the index pregnancy (OR = 1.9 [1.3-2.8]). In particular, ALL was associated with ovulation induction only (OR = 2.6 [1.6-4.3]), but not with in vitro fertilization (IVF, OR = 1.0 [0.4-2.3]) or artificial insemination (OR = 1.3 [0.5-3.9]). A positive association was also observed for the difficulty of becoming pregnant without fertility treatment (OR = 1.5 [1.0-2.1]). AL was positively associated with a history of voluntary abortion (OR = 1.4 [1.1-1.8]) but not with a history of spontaneous (OR = 0.8 [0.7-1.0]) or therapeutic (OR = 0.7 [0.5-1.1]) abortion.

CONCLUSION

The results suggest that subfertility in itself and ovulation induction may be associated with ALL, and support a positive association with congenital malformations. The links with the various types of fertility drugs and the underlying causes of infertility need to be investigated further.

Preimplantation stress and development

The developmental origins of health and disease hypothesis holds that inappropriate environmental cues in utero, a period marked by tremendous developmental sensitivity, facilitate cellular reprogramming to ultimately predispose disease in adulthood. In this review, we analyze if stress during early stages of development can affect future health. This has wide clinical importance, given that 5 million children have been conceived with assisted reproductive technologies (ART). Because the primary outcome of assisted reproduction procedures is delivery at term of a live, healthy baby, the postnatal effects occurring outside ofthe neonatal period are often overlooked. To this end, the long-term outcome of ART is appropriately the most relevant concern of the field today. Evidence of adverse consequences is controversial. The majority of studies have concluded no obvious problems in IVF-conceived children, although a number of isolated cases of imprinted diseases, cancers, or malformations have been reported. Given that animal studies suggest alteration of metabolic pathways following preimplantation stress, it will be of great importance to follow-up ART individuals as they enter later stages of adult life.

Genetic counseling for the orthodox jewish couple undergoing preimplantation genetic diagnosis

Orthodox Jewish patients who seek genetic counseling are often placed in a difficult position of having to choose between their desire to follow Jewish religious instruction (halacha) and following the advice of the genetic counselor. In this article we will present the work of the Puah Institute based in Jerusalem that is dedicated to assisting and guiding such couples to navigate through the medical system and medical recommendations and create a harmony between modern genetic counseling and the Orthodox Jewish tradition. In light of the expanding use of preimplantation genetic diagnosis (PGD) for a variety of medical and non-medical conditions, this dilemma is even more poignant. There is an ethical debate regarding PGD and the correct parameters for its use. Here we present the Orthodox Jewish view of the use and abuse of PGD. We present three case studies that sought the assistance and guidance of the Puah Institute. Each of these cases raises ethical dilemmas for the genetic counselor and for the rabbinic counselor. We discuss; the status of the embryo, the status of a carrier of a genetic abnormality and whether PGD is an obligation or good practice. In addition we deal with whether PGD and the search for the desired traits can be defined as eugenics or not.

Maternal smoking during pregnancy and risk for childhood leukemia: a nationwide case-control study in Greece and meta-analysis

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.

How I treat childhood CML

Chronic myeloid leukemia (CML) is composed of 3% of pediatric leukemias, making evidence-based recommendations difficult. Imatinib has revolutionized the treatment for adult CML by eliminating allogeneic stem cell transplantation for almost all patients in chronic phase. Shown effective in pediatric CML, imatinib and successive tyrosine kinase inhibitors (TKI) have provided more therapeutic options. Because stem cell transplantation has been better tolerated in children and adolescents, the decision to treat by either TKI or transplantation is controversial. We present a recent case of a 12-month-old boy diagnosed with BCR-ABL(+) CML to highlight the controversies in treatment recommendations. We review the pediatric stem cell transplantation outcomes as well as the pediatric experience with imatinib and other TKIs. Finally, we compare the side effects as well as costs associated with allogeneic stem cell transplantation versus TKI therapy. We recommend that frontline therapy for pediatric CML in chronic phase is TKI therapy without transplantation. Patients in accelerated or blast crisis or who fail to reach landmarks on TKIs either because of intolerance or resistance should pursue stem cell transplantation. Although we recommend adopting adult clinical experience to guide therapeutic decision making, the issues of infant CML, drug formulation, pharmacokinetics, and adolescent compliance merit clinical investigation.