Pregnancy and Cancer: Cellular Biology and Mechanisms Affecting the Placenta

Nausea, vomiting and conflict in pregnancy: The adaptive significance of Growth-Differentiation Factor 15

Nausea and vomiting in pregnancy (NVP) is heritable, common and aversive, and its extreme, hyperemesis gravidarum (HG), can be highly deleterious to the mother and fetus. Recent influential studies have demonstrated that HG is caused predominantly by high levels of Growth-Differentiation Factor 15 (GDF15), a hormone produced by the placenta in substantial amounts. This work has led to calls for therapeutic modulation of this hormone to reduce GDF15 levels and ameliorate HG risk. I describe three main lines of evidence relevant to the hypothesis that GDF15 production is typically adaptive for the fetus, in the context of enhanced placental invasion, reduced rates of miscarriage and preterm birth and higher birth weight. These considerations highlight the medical implications of maternal-fetal conflict, in the context of tradeoffs between aversive symptoms during gestation, rare disorders of pregnancy with major adverse effects and moderate fitness-enhancing benefits to fetuses.

Cancer during pregnancy: Twenty-two years of experience from a tertiary referral center

INTRODUCTION

Cancer complicating pregnancy is a rare but potentially life-threatening condition for both the mother and her child. The aim of the present study was to assess the outcomes for mothers and children after pregnancy complicated by malignancy and to investigate which parameters are important for their 1-year survival.

MATERIAL AND METHODS

The study included 84 pregnant women diagnosed with malignant tumors during pregnancy from 2001 to 2022. The pregnancy course and outcome, as well as parameters that could influence the survival and condition of the mother and child were evaluated. Mothers and children were followed up for 1 year after delivery to assess their condition/complications and overall survival.

RESULTS

Most malignancies were gynecological (31%) or hematological (23.8%) and were diagnosed and surgically treated in the second trimester. Most children (69%) showed adequate growth and development throughout pregnancy but were delivered before term (53.6%) to allow mothers to receive therapy. Adjuvant therapy during pregnancy mostly caused a transitory deterioration of the child's condition, while surgery did not significantly impact the pregnancy course. Deliveries, on average, occurred during the 33.01 ± 6.16 gestational week (range: 20-40) and mostly by cesarean section (76.2%). For mothers, the pregnancy survival rate was 95.2% and survival after 1 year was 87.5%. However, 37.5% of women were still ill and required additional therapy 1 year postpartum. The pregnancy survival rate for children was 94%, whereas the 1-year survival rate was 76.2%. Most children had a favorable condition (alive, adequately growing and developing, and without complications) at birth (81%) as well as at the 1-year follow-up (63.7%). Regression analysis identified the following predictors of favorable 1-year maternal condition: applying therapy during pregnancy, no progression of the malignancy during pregnancy, and delivery at a later gestational week. Predictors of favorable 1-year condition of children were lower histopathological grade of malignancy, surgery as therapy for malignancy, obtaining higher birthweight, and delivery by cesarean section.

CONCLUSIONS

If the malignancy is not progressing, pregnancy should be continued as long as possible for the child to obtain adequate birthweight. Both surgery and chemotherapy were safe therapeutic choices, as most pregnancies continued successfully after therapy.

Influence of cancer in pregnancy on obstetric and neonatal outcomes: an observational retrospective cohort study

OBJECTIVE

The study aimed to review the oncological characteristics and treatment of pregnancy-associated cancers and analyze the obstetric and neonatal outcomes to provide evidence-based recommendations for reproductive function preservation, oncological treatment, and obstetric management.

METHODS

We conducted an observational retrospective cohort study among pregnant patients with cancer in 7 Chinese tertiary A hospitals from 2003 to 2021. We conducted multiple logistic regression to determine the influence of various factors on preterm birth and small-for-gestational-age infants, log-binomial regression to analyze temporal changes, and χ² tests to explore the effects of cancer type/treatment.

RESULTS

Of 204 women, 17% terminated their pregnancies; 59% received pre-delivery treatment. Every 6 years, the rates of pregnancy termination (relative risk [RR]=0.48; 95% confidence interval [CI]=0.35-0.67) and iatrogenic preterm births (RR=0.73; 95% CI=0.54-0.98) reduced, and that of pre-delivery treatment increased, mainly due to increased rates of surgery (RR=1.87; 95% CI=1.31-2.67). Maternal systemic diseases were related to small-for-gestational-age infants (odds ratio [OR]=12.02; 95% CI=1.82-79.43). Chemotherapy with taxanes plus platinum-based agents was related to adverse obstetric outcomes (OR=1.87; 95% CI=1.42-2.46; p<0.05). Thyroid (OR=0.36; 95% CI=0.22-0.57) and ovarian cancer (OR=0.70; 95% CI=0.50-0.98) were associated with fewer cesarean sections. Thyroid cancer was associated with fetal growth restriction (OR=5.21; 95% CI=1.21-22.55).

CONCLUSION

Rates of pregnancy termination in cancer declined. Taxane plus platinum-based chemotherapy was associated with adverse obstetric outcomes. Cancer type influenced outcomes.

TRIAL REGISTRATION

Chinese Clinical Trial Register Identifier: ChiCTR2100044292.

Metastatic Lymphomas of the Placenta: A Literature Review With an Illustrative Case

Lymphoma is the fourth most common tumor to display placental metastasis. This study aimed to report a case of high-grade lymphoma involving the placenta and review the literature on lymphomas metastatic to the placenta. A systematic review was performed following the PRISMA guidelines, using the keywords "lymphoma" AND "placenta." All case reports and case series on lymphoma infiltrating the placenta were collected. Eight cases from 7 studies, including the present case, were synthesized. The mean patient age is 29.5 years. The clinical presentation is non-specific. Hematologic derangements included cytopenias or cytoses, and elevated prothrombin time. The mean gestational age (GA) when a diagnosis of lymphoma was rendered is 27 weeks. Five cases presented with either lymphadenopathy or visceral masses on imaging. Four of these cases eventually led to maternal demise. The mean GA when the fetus was delivered is 31 3/4 weeks. Grossly, most placentas had non-specific findings. Leukemic infiltrates were mostly seen within intervillous spaces. Intravillous infiltrates were associated with high-grade lymphomas, resulting in either maternal demise or stillborn fetuses. This study suggests that the placenta has mechanisms to guard against malignancies; however, these defense mechanisms are not foolproof and may be breached by tumor cells.

Incidental Detection of Malignancies With Cell-Free DNA Screening

Cell-free circulating DNA is an evolving technology with important clinical applications in both obstetric care and oncology. In the challenging patient with pregnancy and co-existing malignancy, the utility of cell-free DNA both for aneuploidy screening and cancer identification is an area of active research. Understanding the physiology associated with circulating cell-free DNA and subsequent laboratory evaluation is critical for clinicians caring for the obstetric patient with cell-free fetal DNA screening results suggestive of malignancy. Ongoing research is necessary to determine best practices for the evaluation and management of these patients with promising applications in the advancement of precision medicine.

Immune plasticity in pregnancy-associated breast cancer tumorigenesis

Pregnancy-associated breast cancer (PrBC) is a rare tumor that requires complex management. The coexistence of cancer and pregnancy involves several proliferative, invasive, and immune tolerance mechanisms that are shared between the two conditions. In normal pregnancy, successful fetal development is achieved through suppression of the maternal immune response toward the fetus. Similar immunosuppressive patterns during the malignant transformation supporting tumor growth, progression, and metastasis are also exhibited by tumors. An improved understanding of the immunosuppressive mechanisms and pathways underlying the immunological synergy in PrBC could lead to the identification of novel biomarkers that potentially improve patients' clinical management. In this review article, we outline some of the paramount features of immune plasticity during pregnancy, discussing the similarities shared between normal pregnancy and breast cancer in terms of immune suppression mechanisms. Emphasis is also placed on how the current knowledge of the immune milieu of these conditions may be translated into consequent therapeutic opportunities.

Early Pregnancy Exposure to Ambient Air Pollution among Late-Onset Preeclamptic Cases Is Associated with Placental DNA Hypomethylation of Specific Genes and Slower Placental Maturation

Exposure to ambient air pollution during pregnancy has been associated with an increased risk of preeclampsia (PE). Some suggested mechanisms behind this association are changes in placental DNA methylation and gene expression. The objective of this study was to identify how early pregnancy exposure to ambient nitrogen oxides (NO_x) among PE cases and normotensive controls influence DNA methylation (EPIC array) and gene expression (RNA-seq). The study included placentas from 111 women (29 PE cases/82 controls) in Scania, Sweden. First-trimester NO_x exposure was assessed at the participants’ residence using a dispersion model and categorized via median split into high or low NO_x. Placental gestational epigenetic age was derived from the DNA methylation data. We identified six differentially methylated positions (DMPs, q < 0.05) comparing controls with low NO_x vs. cases with high NO_x and 14 DMPs comparing cases and controls with high NO_x. Placentas with female fetuses showed more DMPs (N = 309) than male-derived placentas (N = 1). Placentas from PE cases with high NO_x demonstrated gestational age deceleration compared to controls with low NO_x (p = 0.034). No differentially expressed genes (DEGs, q < 0.05) were found. In conclusion, early pregnancy exposure to NO_x affected placental DNA methylation in PE, resulting in placental immaturity and showing sexual dimorphism.