Preterm birth, neonatal therapies and the risk of childhood cancer

Risk of childhood neoplasms related to neonatal phototherapy- a systematic review and meta-analysis

CONTEXT

Observational studies have shown conflicting results as to whether exposure to neonatal phototherapy is associated with increased rates of childhood cancer.

OBJECTIVE

To describe the rates of childhood neoplasms and cancer after neonatal phototherapy.

DATA SOURCES

The CENTRAL, PubMed, Scopus, and Web of Science databases.

STUDY SELECTION

Observational studies regardless of design were included.

DATA EXTRACTION

The data were extracted by one author and validated by another. The risk-of-bias assessment was performed using the ROBINS-E and Joanna Briggs Institute critical appraisal tools.

RESULTS

Six cohort and 10 case-control studies were included. The overall risk of bias was high in seven and low in nine studies. In cohort studies, the odds ratio (OR) was increased for hematopoietic cancer (1.44; confidence interval [CI]: 1.16-1.80) and solid tumors (OR: 1.18; CI: 1.00-1.40). In case-control studies, the OR was 1.63 (CI: 0.99-2.67) for hematopoietic cancers and 1.18 (CI: 1.04-1.34) for solid tumors.

CONCLUSIONS

Children with a history of neonatal phototherapy had increased risk of hematopoietic cancer and solid tumors. The evidence quality was limited due to the high risk of bias and potential residual confounding.

IMPACT STATEMENT

Exposure to neonatal phototherapy increased later risk of hematopoietic cancer and solid tumors. This is the most comprehensive study on the association between phototherapy and cancer, but the evidence quality was limited due risk of bias and residual confounding. Future large scale well conducted studies are still needed to better estimate the association and.

Neonatal per- and polyfluoroalkyl substance exposure in relation to retinoblastoma

BACKGROUND

Neonatal per- and polyfluoroalkyl substance (PFAS) exposure can disrupt hormonal homeostasis and induce neuro- and immunotoxicity in children. In this exploratory study, we investigated associations between PFAS levels in neonatal dried blood spots and retinoblastoma risk.

MATERIALS AND METHODS

This study included 501 retinoblastoma cases born from 1983 to 2011 and 899 controls frequency-matched by birth year (20:1 matching ratio), born to 755 US-born and 366 Mexico-born mothers in California. Perfluorooctanesulfonic acid (PFOS), perflurooctanoic acid (PFOA), and perfluorononanoic acid (PFNA) feature intensities were identified from neonatal blood spots from California newborn Genetic Disease Screening Program. Using logistic regression, we assessed whether an interquartile range (IQR) increase of PFAS levels or having above-mean levels of PFAS in blood affects retinoblastoma risk overall or its subtypes (i.e., unilateral, bilateral). We assessed children of US-born and Mexico-born mothers, separately.

RESULTS AND DISCUSSION

Among all children, above-mean PFOS levels at birth increased the odds of retinoblastoma overall by 29% (95% Confidence Interval (CI): 1.00, 1.67) and unilateral retinoblastoma by 42% (95% CI: 1.03, 1.97). For children of Mexico-born mothers, we estimated the highest odds of retinoblastoma overall (adjusted odds ratio (aOR): 1.67; 95% CI: 1.06, 2.66) and bilateral retinoblastoma (aOR: 2.06; 95% CI: 1.12, 3.92) with above-mean PFOS levels. Among children of US-born mothers, higher PFOS levels increased the odds of unilateral retinoblastoma by 15% (95% CI: 0.99, 1.35) for each IQR increase and by 71% among children with above-mean PFOS levels (95% CI: 1.04, 2.90). In addition, for children of US-born mothers, PFOA increased the odds of retinoblastoma overall (aOR: 1.41; 95% CI: 1.00, 2.02 for above-mean levels, aOR: 1.06; 95% CI: 0.98, 1.16 per IQR increase). PFNA was not associated with retinoblastoma risk.

CONCLUSIONS

Our results suggested that PFOS and PFOA might contribute to retinoblastoma risk in children born in California.

Consequences of Preterm Birth: Knowns, Unknowns, and Barriers to Advancing Cardiopulmonary Health

Preterm birth occurs in 10% of all live births and creates challenges to neonatal life, which persist into adulthood. Significant previous work has been undertaken to characterize and understand the respiratory and cardiovascular sequelae of preterm birth, which are present in adulthood, i.e., "late" outcomes. However, many gaps in knowledge are still present and there are several challenges that will make filling these gaps difficult. In this perspective we discuss the obstacles of studying adults born preterm, including (1) the need for invasive (direct) measures of physiologic function; (2) the need for multistate, multinational, and diverse cohorts; (3) lack of socialized medicine in the United States; (4) need for detailed and better-organized birth records; and (5) transfer of neonatal and pediatric knowledge to adult care physicians. We conclude with a discussion on the "future" of studying preterm birth in regards to what may happen to these individuals as they approach middle and older age and how the improvements in perinatal and postnatal care may be changing the phenotypes observed in adults born preterm on or after the year 2000.

Danish Population Based Study of Familial Epilepsy and Childhood Cancer

Objective

Results from studies investigating the association between maternal or child epilepsy, use of anticonvulsants in pregnancy, and childhood cancer are inconsistent and at times contradictory.

Methods

Linking Danish national databases, we obtained epilepsy and childhood cancer diagnoses, and anticonvulsant use data. We estimated adjusted odds ratios of all or specific childhood cancers in relation to maternal or child epilepsy and anticonvulsant therapies using conditional logistic regression.

Results

Maternal epilepsy was positively associated with all childhood cancers in offspring, specifically, with acute lymphoblastic leukemia (Odds Ratio (OR) = 1.68, 95% Confidence Interval (CI) = 1.16, 2.43) and Wilms tumor (OR = 2.13, 95%CI = 0.97, 4.68). When considering maternal ever (lifetime) ingestion of anticonvulsants, a positive association was found with all cancers (OR = 1.15, 95%CI = 1.01, 1.31), and central nervous system tumors (OR = 1.32, 95%CI = 1.03, 1.69) as well as neuroblastoma (OR = 2.05, 95%CI = 1.29, 3.28) among offspring. Maternal anticonvulsant use before or during the index pregnancy was related to CNS tumors in offspring (OR = 1.78, 95%CI = 0.99, 3.21), however the confidence interval included the null.

Significance

Maternal use of certain anticonvulsant medications may be a risk factor for cancer in offspring. Medical providers may need to consider what type of treatments to prescribe to pregnant mothers with epilepsy.

Association of Maternal and Neonatal Birth Outcomes With Subsequent Pediatric Transplants

BACKGROUND

We identified maternal and neonatal birth characteristics that were associated with organ or tissue transplants during childhood.

METHODS

We designed a retrospective cohort study of the population of children born between 2006 and 2019 in Quebec, Canada. The exposure included birth complications such as congenital anomaly, neonatal blood transfusion, and oligohydramnios. The main outcome measure was organ or tissue transplantation before 14 y of age. We categorized transplants according to type (major organs versus superficial tissues). To determine the association of birth characteristics with risk of pediatric transplant, we estimated hazard ratios (HRs) and 95% confidence intervals (CIs) using Cox proportional hazards models adjusted for potential confounders.

RESULTS

The cohort comprised 1 038 375 children with 7 712 678 person-years of follow-up, including 436 children who had transplants before 14 y of age. Birth complications were predominantly associated with major organ transplants. Congenital anomaly was associated with heart or lung (HR, 10.41; 95% CI, 5.33-20.33) and kidney transplants (HR, 13.69; 95% CI, 7.48-25.06), compared with no anomaly. Neonatal blood transfusion was associated with all major organ transplants, compared with no transfusion. Maternal complications were not as strongly associated with the risk of childhood transplant, although oligohydramnios was associated with 16.84 times (95% CI, 8.09-35.02) the risk of kidney transplant, compared with no oligohydramnios.

CONCLUSIONS

Adverse birth outcomes such as congenital anomaly, neonatal blood transfusion, and maternal oligohydramnios are associated with a greater risk of transplantation before 14 y of age. Maternal and neonatal birth outcomes may be useful predictors of transplantation.

Is neonatal phototherapy associated with a greater risk of childhood cancers?

Background

Neonatal phototherapy (NNPT) has long been used as an effective and relatively safe method of treating neonatal hyperbilirubinemia. Considering the subsequent evidence of long-term impacts of NNPT such as malignancies, this study was conducted to evaluate the relationship between NNPT and childhood cancers.

Methods

This case-control study assessed 116 children up to 4 years old with every kind of cancer referred to the Oncology department of Afzalipour hospital, Kerman, Iran, from 2011 to 18. Moreover, 116 pediatric patients without cancer hospitalized at the same Center were included after sex and age matching as the control group. The history of phototherapy and its duration were evaluated in these two groups.

Results

We found no association between the NNPT and malignancies in children. However, high intensive phototherapy was higher historically among affected cancerous patients than in non-cancerous cases without any statistically significant difference (25% vs 19%; P = 0.26). Maternal educational level and history of maternal infection during pregnancy, which initially appeared to be two factors associated with malignancy in single variable regression analyses, were not significant based on the adjusted models.

Conclusions

The results did not show a positive correlation between NNPT and childhood cancers, which may partly be due to the relatively small sample size of the study. However, some other evidence is worrisome enough that NNPT should not be considered risk-free. Additional multi-centric studies should be undertaken to specify that phototherapy is really safe.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12887-022-03412-0.

Association Between Neonatal Phototherapy Exposure and Childhood Neoplasm

OBJECTIVE

To study the association between phototherapy for the treatment of neonatal jaundice and the risk of childhood neoplasms.

STUDY DESIGN

This population-based retrospective cohort study included all infants born at ≥32 weeks of gestation at a single medical center between 1988 and 2018. The incidence of neoplastic diseases was compared between infants exposed to phototherapy and those unexposed. Kaplan-Meier curves and log-rank tests were used for cumulative incidence comparison, and multivariable Cox and Weibull survival analysis were used to adjust for confounding or clinically significant variables.

RESULTS

The study population included 342 172 infants, of whom 18 797 (5.5%) were exposed to phototherapy. The median duration of follow-up was 9.5 years (range, birth to 18 years). Phototherapy was associated with a significantly increased risk for childhood malignancies and benign tumors (preterm birth and maternal age-adjusted hazard ratio, 1.89 [95% CI, 1.35-2.67] for malignancies and 1.27 [95% CI, 1.02-1.57] for benign tumors) Specifically, phototherapy was associated with hematopoietic cancers and leukemia (hazard ratio, 2.29 [95% CI, 1.48-3.54; P < .01] for hematopoietic cancers and 2.51 [95% CI, 1.52-4.14; P < .001] for leukemia), but not with solid tumors and lymphoma.

CONCLUSIONS

Phototherapy may be associated with a slightly increased childhood risk of neoplasm. It is important to strictly follow phototherapy treatment guidelines to minimize unnecessary exposure.

Medication-Associated Phthalate Exposure and Childhood Cancer Incidence

BACKGROUND

Human phthalate exposure is widespread through contact with myriad consumer products. Exposure is particularly high through medications formulated with phthalates. Phthalates disrupt normal endocrine signaling and are associated with reproductive outcomes and incidence of some cancers. We measured associations between gestational and childhood medication-associated phthalate exposures and the incidence of childhood cancers.

METHODS

We identified all live births in Denmark between 1997 and 2017, including both children and birth mothers. Using drug ingredient data merged with the Danish National Prescription Registry, we measured phthalate exposure through filled prescriptions for mothers during pregnancy (gestational exposure) and for children from birth until age 19 years (childhood exposure). Incident childhood cancers were ascertained from the Danish Cancer Registry, and associations were estimated with Cox regression models.

RESULTS

Among 1 278 685 children, there were 2027 childhood cancer cases diagnosed over 13.1 million person-years of follow-up. Childhood phthalate exposure was strongly associated with incidence of osteosarcoma (hazard ratio [HR] = 2.78, 95% confidence interval [CI] = 1.63 to 4.75). We also observed a positive association with incidence of lymphoma (HR = 2.07, 95% CI = 1.36 to 3.14), driven by associations with Hodgkin and non-Hodgkin lymphoma but not Burkitt lymphoma. Associations were apparent only for exposure to low-molecular phthalates, which have purportedly greater biological activity.

CONCLUSIONS

Childhood phthalate exposure was associated with incidence of osteosarcoma and lymphoma before age 19 years. Lingering questions include which specific phthalate(s) are responsible for these associations, by what mechanisms they occur, and to what extent childhood cancer cases could be avoided by reducing or eliminating the phthalate content of medications and other consumer products.

Maternal Thyroid Disease and the Risk of Childhood Cancer in the Offspring

Maternal thyroid disease, especially hypothyroidism, affects pregnancy and its outcome. In-utero exposure to autoimmune thyroid disease has been reported to associate with childhood ALL in the offspring. We evaluated the risk of childhood cancer in the offspring following exposure to maternal thyroid disease in a case-control setting using registry data. All patients with their first cancer diagnosis below the age of 20 years were identified from the Finnish Cancer Registry (n = 2037) and matched for sex and birth year at a 1:5 ratio to population controls identified from the Medical Birth Registry (n = 10,185). We collected national information on maternal thyroid disease from the Medical Birth Registry, Care Register for Health Care, Register for Reimbursed Drug Purchases and Register of Special Reimbursements. We used conditional logistic regression to analyze childhood cancer risk in the offspring. The adjusted OR for any childhood cancer was 1.41 (95%, CI 1.00-2.00) comparing the offspring of mothers with hypothyroidism and those with normal thyroid function. The risk of lymphomas was increased (adjusted OR for maternal hypothyroidism 3.66, 95%, CI 1.29-10.38). The results remained stable when mothers with cancer history were excluded from the analyses. Maternal hypothyroidism appears to be associated with an increased risk for childhood lymphoma in the offspring. The association exists even after excluding possible familial cancers.

Cancer risk in individuals with intellectual disability in Sweden: A population-based cohort study

BACKGROUND

A knowledge gap exists about the risk of cancer in individuals with intellectual disability (ID). The primary aim of this study was to estimate the cancer risk among individuals with ID compared to individuals without ID.

METHODS AND FINDINGS

We conducted a population-based cohort study of all children live-born in Sweden between 1974 and 2013 and whose mothers were born in a Nordic country. All individuals were followed from birth until cancer diagnosis, emigration, death, or 31 December 2016 (up to age 43 years), whichever came first. Incident cancers were identified from the Swedish Cancer Register. We fitted Cox regression models to calculate hazard ratios (HRs) and 95% confidence intervals (CIs) as measures of cancer risk in relation to ID after adjusting for several potential confounders. We analyzed ID by severity, as well as idiopathic ID and syndromic ID separately. We performed a sibling comparison to investigate familial confounding. The study cohort included a total of 3,531,305 individuals, including 27,956 (0.8%) individuals diagnosed with ID. Compared with the reference group (individuals without ID and without a full sibling with ID), individuals with ID were in general more likely to be male. The median follow-up time was 8.9 and 23.0 years for individuals with ID and individuals without ID, respectively. A total of 188 cancer cases were identified among individuals with ID (incidence rate [IR], 62 per 1,000 person-years), and 24,960 among individuals in the reference group (IR, 31 per 1,000 person-years). A statistically significantly increased risk was observed for any cancer (HR 1.57, 95% CI 1.35-1.82; P < 0.001), as well as for several cancer types, including cancers of the esophagus (HR 28.4, 95% CI 6.2-130.6; P < 0.001), stomach (HR 6.1, 95% CI 1.5-24.9; P = 0.013), small intestine (HR 12.0, 95% CI 2.9-50.1; P < 0.001), colon (HR 2.0, 95% CI 1.0-4.1; P = 0.045), pancreas (HR 6.0, 95% CI 1.5-24.8; P = 0.013), uterus (HR 11.7, 95% CI 1.5-90.7; P = 0.019), kidney (HR 4.4, 95% CI 2.0-9.8; P < 0.001), central nervous system (HR 2.7, 95% CI 2.0-3.7; P < 0.001), and other or unspecified sites (HR 4.8, 95% CI 1.8-12.9; P = 0.002), as well as acute lymphoid leukemia (HR 2.4, 95% CI 1.3-4.4; P = 0.003) and acute myeloid leukemia (HR 3.0, 95% CI 1.4-6.4; P = 0.004). Cancer risk was not modified by ID severity or sex but was higher for syndromic ID. The sibling comparison showed little support for familial confounding. The main study limitations were the limited statistical power for the analyses of specific cancer types, and the potential for underestimation of the studied associations (e.g., due to potential underdetection or delayed diagnosis of cancer among individuals with ID).

CONCLUSIONS

In this study, we found that individuals with ID showed an increased risk of any cancer, as well as of several specific cancer types. These findings suggest that extended surveillance and early intervention for cancer among individuals with ID are warranted.

Maternal autoimmune disease is not associated with cancer in the offspring

AIM

Autoimmune disease and its medication are associated with increased cancer risk in adults, but it is unknown whether maternal autoimmune disease and/or medication use in pregnancy are associated with increased cancer risk in offspring.

METHODS

In this case-control study, we identified all patients under 20 years of age with their first cancer diagnosis in 1996-2014 from the Finnish Cancer Registry (n = 2029) and 1:5 population-based controls (n = 10,103) from the Medical Birth Register. We obtained information on maternal autoimmune disease and its medication from the relevant Finnish registries and used conditional logistic regression to analyse the risk of offspring cancer after maternal autoimmune disease exposure.

RESULTS

The odds ratio (OR) for cancer in offspring following maternal autoimmune exposure was 0.76 (95% confidence interval [CI] 0.47-1.23). Individual ORs for inflammatory bowel and connective tissue diseases were 1.08 (95% CI 0.56-2.01) and 0.50 (95% CI 0.23-1.08), respectively. The OR for maternal autoimmune medication was 0.95 (95% CI 0.80-1.14) overall and similar by drug subtype. There was an increased risk with medication in late pregnancy but the ORs were unstable owing to small numbers.

CONCLUSION

Our study does not support an increased cancer risk among offspring of women with autoimmune disease or its medication during pregnancy.