Effects of in-utero exposure to chemotherapy on fetal brain growth

Shaping the risk for late-life neurodegenerative disease: A systematic review on prenatal risk factors for Alzheimer's disease-related volumetric brain biomarkers

Environmental exposures including toxins and nutrition may hamper the developing brain in utero, limiting the brain's reserve capacity and increasing the risk for Alzheimer's disease (AD). The purpose of this systematic review is to summarize all currently available evidence for the association between prenatal exposures and AD-related volumetric brain biomarkers. We systematically searched MEDLINE and Embase for studies in humans reporting on associations between prenatal exposure(s) and AD-related volumetric brain biomarkers, including whole brain volume (WBV), hippocampal volume (HV) and/or temporal lobe volume (TLV) measured with structural magnetic resonance imaging (PROSPERO; CRD42020169317). Risk of bias was assessed using the Newcastle Ottawa Scale. We identified 79 eligible studies (search date: August 30th, 2020; Ntotal=24,784; median age 10.7 years) reporting on WBV (N = 38), HV (N = 63) and/or TLV (N = 5) in exposure categories alcohol (N = 30), smoking (N = 7), illicit drugs (N = 14), mental health problems (N = 7), diet (N = 8), disease, treatment and physiology (N = 10), infections (N = 6) and environmental exposures (N = 3). Overall risk of bias was low. Prenatal exposure to alcohol, opioids, cocaine, nutrient shortage, placental dysfunction and maternal anemia was associated with smaller brain volumes. We conclude that the prenatal environment is important in shaping the risk for late-life neurodegenerative disease.

Direct and indirect effects on child neurocognitive development when maternal cancer is diagnosed during pregnancy: What do we know so far?

Cancer during pregnancy threatens the lives of mother and foetus and its incidence is rising, making it an emerging medical challenge. Evidence on the direct impact of cancer therapies on neonatal outcomes resulted in general guidelines for maternal treatment that safeguards foetal development. Less focus has been placed on indirect factors, in pre- and postnatal periods, that may exert long-term impacts specifically on child neurocognition. Foetal development, in the context of maternal cancer during pregnancy, may be influenced directly by exposure to cancer diagnostics and (co-)treatment, or indirectly through maternal inflammation, malnutrition, hormonal fluctuations, prematurity, and psycho-biological stress. Maternal stress and insecure mother-infant bonding related to postpartum cancer treatment may further impact child cognitive-behavioural development. Understanding the independent and synergistic effects of the factors impacting neurocognitive development creates the opportunity to intervene during the oncological treatment to improve the child's long-term outcome, both by medical and psychosocial care and support.

Transplacental Passage and Fetal Effects of Antineoplastic Treatment during Pregnancy

Simple Summary

In this paper we perform an introduction about pregnancy-associated cancer (PAC) and transplacental passage of antineoplastic agents. Furthermore, we describe therapeutic use and potential toxic effects of chemotherapeutic drug (alkylating agents, antimetabolites agents, anthracyclines, topoisomerase inhibitors, antimitotic agents, actinomycin-D, bleomycin) and targeted agents during pregnancy. This manuscript may be a useful and practical guide for the management of PAC, which is a challenge for clinicians that have to consider alike maternal benefits and fetal potential risks correlated to the antineoplastic treatment.

Abstract

The incidence of PAC is relatively infrequent among pregnant women. However, it has gradually increased in recent years, becoming a challenging area for clinicians that should take into account in the same way maternal benefits and fetal potential risks correlated to the antineoplastic treatment. None of the antineoplastic drugs is completely risk-free during the pregnancy, the timing of exposure and transplacental transfer properties influence the toxicity of the fetus. Despite the lack of guidelines about the management of PAC, several studies have described the use and the potential fetal and neonatal adverse events of antineoplastic drugs during pregnancy. We provide a review of the available literature about the transplacental passage and fetal effects of chemotherapy and targeted agents, to guide the clinicians in the most appropriate choices for the management of PAC.

Cancer during Pregnancy: A Review of Preclinical and Clinical Transplacental Transfer of Anticancer Agents

The occurrence of cancer during pregnancy is observed in 1 in 1000 pregnancies and is expected to increase given the trend of delaying childbearing. While breast cancer is the most common, the incidence of other cancers, such as cervical, ovarian, and lung cancers as well as hemopathies and melanomas, is also increasing. Thus, cancer occurrence in pregnant women raises questions of management during pregnancy and, especially, assessment of the treatment benefit-risk ratio to ensure optimal management for the mother while ensuring the safety of the fetus. Chemotherapy remains a cornerstone of cancer management. If the use of anticancer agents appears possible during pregnancy, while avoiding the first trimester, the extent of placental transfer of different anticancer agents varies considerably thereafter. Furthermore, the significant physiological pharmacokinetic variations observed in pregnant women may have an impact on the placental transfer of anticancer agents. Given the complexity of predicting placental transfer of anticancer agents, preclinical studies are therefore mandatory. The aim of this review was to provide updated data on in vivo and ex vivo transplacental transfer of anticancer agents used in the management of the most common pregnancy-associated cancers to better manage these highly complex cases.

Management of pregnancy in women with cancer

As the incidence of cancer in pregnancy has been increasing in recent decades, more specialists are confronted with a complex oncologic–obstetric decision-making process. With the establishment of (inter)national registries, including the International Network on Cancer, Infertility and Pregnancy, and an increasing number of smaller cohort studies, more evidence on the management of cancer during pregnancy is available. As fetal, neonatal, and short-term pediatric outcomes after cancer treatment are reassuring, more women receive treatment during pregnancy. Prenatal treatment should adhere to standard treatment as much as possible to optimize maternal prognosis, always taking into account fetal well-being. In order to guarantee the optimal treatment for both mother and child, a multidisciplinary team of specialists with expertise should be involved. Apart from oncologic treatment, a well-considered obstetric and perinatal management plan discussed with the future parents is crucial. Results of non-invasive prenatal testing are inconclusive in women with cancer and alternatives for prenatal anomaly screening should be used. Especially in women treated with chemotherapy, serial ultrasounds are strongly recommended to follow-up fetal growth and cervical length. After birth, a neonatal assessment allows the identification of any cancer or treatment-related adverse events. In addition, placental histologic examination aims to assess the fetal risk of metastasis, especially in women with malignant melanoma or metastatic disease. Breastfeeding is discouraged when systemic treatment needs to be continued after birth. At least a 3-week interval between the last treatment and nursing is recommended to prevent any treatment-induced neonatal effects from most non-platinum chemotherapeutic agents.

Long-Term Neurodevelopmental Outcome of Children after in Utero Exposure to Chemotherapy

Simple Summary

Facing cancer diagnosis during pregnancy constitutes a truly complex and challenging situation for both the patients and the physicians. Cancer diagnosis in a period of hope and joy is an unendurable situation that may affect the psychosocial functioning of the mother, causing depression, anxiety, self-blame, and social isolation. At the same time, a moral dilemma evolves among medical professionals; what is best for the mother in terms of immediate chemotherapy may have detrimental effects on the fetus, and conversely, delaying therapy and protecting the fetus may have a negative impact on the mother as the tumor progresses. Solid data on the safety profile or risks of anti-cancer agents and on the long-term neurodevelopmental outcome of children after in utero exposure to chemotherapy may provide both the patients and the physicians the information necessary for shared decision making when cancer is diagnosed during pregnancy.

Abstract

Pregnancy-related cancer management represents a real challenge for both the patients and the physicians. The long-term neurodevelopmental outcome of children in utero exposed to chemotherapeutic agents has only recently been addressed. This review aims to systematically integrate and highlight all existing data from the literature regarding the effect of prenatal exposure to chemotherapy on fetal brain growth and child development. All eligible studies are based on validated neurodevelopmental testing scales (e.g., Bayley Scales of Infant Development, Wechsler Preschool and Primary Scale of Intelligence) and/or well-defined questionnaires. Our systematic review including 17 studies demonstrates that no major consequences on the neurodevelopment of children after in utero exposure to anti-cancer drugs have been reported; nevertheless, longer and more thorough follow-up with large-scale multicenter prospective studies is certainly required in order to draw firm conclusions.

The impact of cancer and chemotherapy during pregnancy on child neurodevelopment: A multimodal neuroimaging analysis

BACKGROUND

This study applies multimodal MRI to investigate neurodevelopment in nine-year-old children born to cancer-complicated pregnancies.

METHODS

In this cohort study, children born after cancer-complicated pregnancies were recruited alongside 1:1 matched controls regarding age, sex and gestational age at birth (GA). Multimodal MRI was used to investigate whole-brain and subcortical volume, cortical structure (using surface-based morphometry), white matter microstructure (using fixel-based analysis) and functional connectivity (using resting-state blood-oxygen-level-dependant signal correlations). Graph theory probed whole-brain structural and functional organization. For each imaging outcome we conducted two group comparisons: 1) children born after cancer-complicated pregnancies versus matched controls, and 2) the subgroup of children with prenatal chemotherapy exposure versus matched controls. In both models, we used the covariate of GA and the group-by-GA interaction, using false-discovery-rate (FDR) or family-wise-error (FWE) correction for multiple comparisons. Exploratory post-hoc analyses investigated the relation between brain structure/function, neuropsychological outcome and maternal oncological/obstetrical history.

FINDINGS

Forty-two children born after cancer-complicated pregnancies were included in this study, with 30 prenatally exposed to chemotherapy. Brain organization and functional connectivity were not significantly different between groups. Both cancer and chemotherapy in pregnancy, as compared to matched controls, were associated with a lower travel depth, indicating less pronounced gyrification, in the left superior temporal gyrus (pFDR ≤ 006), with post-hoc analysis indicating platinum derivatives during pregnancy as a potential risk factor (p = .028). Both cancer and chemotherapy in pregnancy were related to a lower fibre cross-section (FCS) and lower fibre density and cross-section (FDC) in the posterior corpus callosum and its tapetal fibres, compared to controls. Higher FDC in the chemotherapy subgroup and higher FCS in the whole study group were observed in the anterior thalamic radiations. None of the psycho-behavioural parameters correlated significantly with any of the brain differences in the study group or chemotherapy subgroup.

INTERPRETATION

Prenatal exposure to maternal cancer and its treatment might affect local grey and white matter structure, but not functional connectivity or global organization. While platinum-based therapy was identified as a potential risk factor, this was not the case for chemotherapy in general.

FUNDING

This project has received funding from the European Union's Horizon 2020 research and innovation program (European Research council, grant no 647,047), the Foundation against cancer (Stichting tegen kanker, grant no. 2014-152) and the Research Foundation Flanders (FWO, grants no. 11B9919N, 12ZV420N).

Pregnancy and Cancer: the INCIP Project

PURPOSE OF REVIEW

Cancer diagnosis in young pregnant women challenges oncological decision-making. The International Network on Cancer, Infertility and Pregnancy (INCIP) aims to build on clinical recommendations based on worldwide collaborative research.

RECENT FINDINGS

A pregnancy may complicate diagnostic and therapeutic oncological options, as the unborn child must be protected from potentially hazardous exposures. Pregnant patients should as much as possible be treated as non-pregnant patients, in order to preserve maternal prognosis. Some approaches need adaptations when compared with standard treatment for fetal reasons. Depending on the gestational age, surgery, radiotherapy, and chemotherapy are possible during pregnancy. A multidisciplinary approach is the best guarantee for experience-driven decisions. A setting with a high-risk obstetrical unit is strongly advised to safeguard fetal growth and health. Research wise, the INCIP invests in clinical follow-up of children, as cardiac function, neurodevelopment, cancer occurrence, and fertility theoretically may be affected. Furthermore, parental psychological coping strategies, (epi)genetic alterations, and pathophysiological placental changes secondary to cancer (treatment) are topics of ongoing research. Further international research is needed to provide patients diagnosed with cancer during pregnancy with the best individualized management plan to optimize obstetrical and oncological care.