Cancer cell transmission via the placenta

Cross-individual cancer transmission to children during the gestational and perinatal periods

Cancer transmission may rarely occur between individuals. Besides through allogenic transplantation, cancer transmission via the hemochorial placenta, which is permissive for cell traffic, has been described in a few reports. Three etiologies of transplacental cancer transmission include (1) maternofetal transmission of maternal cancer cells, (2) transmission of gestational choriocarcinoma to the fetus, and (3) transfer of preleukemic cells from one monozygotic twin to the other. Additionally, we recently reported two pediatric cases of lung tumors in which the lung-only distribution of tumors and genomic profiling of both the child's and mother's tumor samples suggested the airway/transbronchial transmission of maternal cervical cancer cells to the child by aspiration at birth. The immune system coordinates the hemostatic balance between effector and regulatory immunity, especially during fetal development. The immunoregulatory properties are shared in both physiological pregnancy-related and pathological cancer-related conditions. Mechanistically, the survival and colonization of transmitted cancer cells within a child are likely attributed to a combination of the child's immune tolerance and the cancer's immune escape. In this review, we summarize the current understanding of gestational/perinatal cancer transmission and discuss the possible mechanism-based immunotherapy for this rare form of pediatric cancer.

Cancer in pregnancy - The obstetrical management

Cancer in pregnancy, defined as a cancer diagnosed during pregnancy, is a rare but severe condition presenting both clinical and ethical challenges. During the last two decades a paradigm shift has occurred towards recommending similar staging and treatment regimens of pregnant and non-pregnant cancer patients. This strategy is a result of an increasing number of reassuring reports on chemotherapy treatment in pregnancy after the first trimester. The management of cancer in pregnancy should be managed in a multidisciplinary team where staging, oncological treatment, social and mental care, timing of delivery, and follow-up of the infant should be planned. Due to the rarity, centralization is recommended to allow experience accumulation. Furthermore, national and international advisory boards are supportive when there is a lack of expertise.

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.

Evolutionary determinants of curability in cancer

The emergence of drug-resistant cells, most of which have a mutated TP53 gene, prevents curative treatment in most advanced and common metastatic cancers of adults. Yet, a few, rarer malignancies, all of which are TP53 wild type, have high cure rates. In this Perspective, we discuss how common features of curable cancers offer insights into the evolutionary and developmental determinants of drug resistance. Acquired loss of TP53 protein function is the most common genetic change in cancer. This probably reflects positive selection in the context of strong ecosystem pressures including microenvironmental hypoxia. Loss of TP53's functions results in multiple fitness benefits and enhanced evolvability of cancer cells. TP53-null cells survive apoptosis, and tolerate potent oncogenic signalling, DNA damage and genetic instability. In addition, critically, they provide an expanded pool of self-renewing, or stem, cells, the primary units of evolutionary selection in cancer, making subsequent adaptation to therapeutic challenge by drug resistance highly probable. The exceptional malignancies that are curable, including the common genetic subtype of childhood acute lymphoblastic leukaemia and testicular seminoma, differ from the common adult cancers in originating prenatally from embryonic or fetal cells that are developmentally primed for TP53-dependent apoptosis. Plus, they have other genetic and phenotypic features that enable dissemination without exposure to selective pressures for TP53 loss, retaining their intrinsic drug hypersensitivity.

Chronic Myeloid Leukemia During Pregnancy with Placental Involvement: Case Report and Literature Review

Introduction: Chronic myeloid leukemia (CML) occurrence during pregnancy is unusual due to the low prevalence of the disease in women of childbearing age, with only three reported cases. Case report: The mother was diagnosed with CML with positive BCR-ABL gene fusion in her 32nd week of gestation. The placenta showed an increased population of myelocytes and segmented neutrophils in the intervillous space and features of maternal villous malperfusion (increased perivillous fibrinoid material and distal villous hypoplasia). The mother underwent leukapheresis and delivered the neonate at 33 wk gestation. The neonate demonstrated neither leukemia nor other pathology. The mother is in remission after four years of follow-up. Conclusion: Leukapheresis was performed safely during pregnancy and provided a safe management strategy until the delivery one week later.

Gestational trophoblastic neoplasia with concurrent metastasis to the mother and child: a systematic literature review

Gestational trophoblastic neoplasia (GTN) arising in the placenta and presenting as a metastatic disease concurrently in the mother and the baby is extremely rare. GTN poses a diagnostic dilemma to the treating clinicians. In the current review, an electronic search of Scopus, PubMed, Embase and other databases was conducted for case reports and case series of GTN co-existing or metastatic to both the mother and the baby, published to date. Globally, a total of twenty-two cases of GTN with metastasis to both the mother and baby was found. The previous history of histopathology confirmed molar pregnancy was present in 4/22 cases. The median time to diagnose GTN in the mother was six weeks post-partum. In the majority of cases, diagnosis of maternal disease was made after the infant presented with clinical manifestation. Overall survival was reported in 17/22 mothers up to varying latest follow-up and in 6/22 infants. A knowledge of the varied clinical presentation, eliciting a history of previous pregnancy loss/term pregnancy and serum beta human chorionic gonadotrophin (β-hCG) estimations were helpful for early diagnosis. The concurrent presence of GTN in the mother and baby is a rare entity and poses a diagnostic dilemma. Diagnosis in the mother often follows diagnosis in the baby after an infant presents with clinical manifestations. GTN is a highly chemo-sensitive tumour, but the main prognostic factors determining survival are the time to diagnosis following previous pregnancy and serum β-hCG levels.

Is chimerism associated with cancer across the tree of life?

Chimerism is a widespread phenomenon across the tree of life. It is defined as a multicellular organism composed of cells from other genetically distinct entities. This ability to 'tolerate' non-self cells may be linked to susceptibility to diseases like cancer. Here we test whether chimerism is associated with cancers across obligately multicellular organisms in the tree of life. We classified 12 obligately multicellular taxa from lowest to highest chimerism levels based on the existing literature on the presence of chimerism in these species. We then tested for associations of chimerism with tumour invasiveness, neoplasia (benign or malignant) prevalence and malignancy prevalence in 11 terrestrial mammalian species. We found that taxa with higher levels of chimerism have higher tumour invasiveness, though there was no association between malignancy or neoplasia and chimerism among mammals. This suggests that there may be an important biological relationship between chimerism and susceptibility to tissue invasion by cancerous cells. Studying chimerism might help us identify mechanisms underlying invasive cancers and also could provide insights into the detection and management of emerging transmissible cancers.

Maternal and Child Health, Non-Communicable Diseases and Metabolites

Mothers influence the health and disease trajectories of their children, particularly during the critical developmental windows of fetal and neonatal life reflecting the gestational-fetal and lactational-neonatal phases. As children grow and develop, they are exposed to various stimuli and insults, such as metabolites, that shape their physiology and metabolism to impact their health. Non-communicable diseases, such as diabetes, cardiovascular disease, cancer and mental illness, have high global prevalence and are increasing in incidence. Non-communicable diseases often overlap with maternal and child health. The maternal milieu shapes progeny outcomes, and some diseases, such as gestational diabetes and preeclampsia, have gestational origins. Metabolite aberrations occur from diets and physiological changes. Differential metabolite profiles can predict the onset of non-communicable diseases and therefore inform prevention and/or better treatment. In mothers and children, understanding the metabolite influence on health and disease can provide insights for maintaining maternal physiology and sustaining optimal progeny health over the life course. The role and interplay of metabolites on physiological systems and signaling pathways in shaping health and disease present opportunities for biomarker discovery and identifying novel therapeutic agents, particularly in the context of maternal and child health, and non-communicable diseases.

Fetal and placental metastases associated with maternal cancers

PURPOSE

Review the effects of fetal and placental metastases in the setting of maternal cancer.

METHOD

Data reported in the peer-reviewed literature were combined with guidelines to evaluate the incidence, type and prognosis for fetal and placental metastasis in the setting of maternal cancer.

RESULTS

Limited literature available. Fetal and placental metastasis are rare. Fetal metastasis generally occurs on the background of concurrent placental metastasis thus it is important to thoroughly examine the placenta in cases of known gestational cancers. Tumor molecular testing is used to confirm maternal to offspring transmission. Maternal to offspring transmission may have a long timeline between birth to clinical presentation. Prognosis in offspring may be better than in the mother who may have a more aggressive phenotype.

CONCLUSION

Fetal and placental metastasis associated with maternal cancers are rare and limited peer-reviewed literature is available. The occurrence may be confirmed by detailed histological placental evaluation and molecular testing in the offspring.

Cancer Is Associated with the Emergence of Placenta-Reactive Autoantibodies

Placenta-specific antigens are minimally expressed or unexpressed in normal adult tissues, while they are widely expressed in cancer. In the course of carcinogenesis, a vast array of autoantibodies (AAbs) is produced. Here, we used a quantitative approach to determine the reactivity of AAbs in the sera of patients with breast (BrC: N = 100, 100% female, median age: 51 years), gastric (GC: N = 30, 46.6% female, median age: 57 years), bladder (BC: N = 29, 34.4% female, median age: 57 years), and colorectal (CRC: N = 34, 41.1% female, median age: 51 years) cancers against first-trimester (FTP) and full-term placental proteome (TP) in comparison with age- and sex-matched non-cancer individuals. Human-on-human immunohistochemistry was used to determine reactive target cells in FTP. The effect of pregnancy on the emergence of placenta-reactive autoantibodies was tested using sera from pregnant women at different trimesters of pregnancy. Except for BC, patients with BrC (p < 0.0284), GC (p < 0.0002), and CRC (p < 0.0007) had significantly higher levels of placenta-reactive AAbs. BrC (p < 0.0001) and BC (p < 0.0409) in the early stages triggered higher autoantibody reactivity against FTP. The reactivities of BrC sera with FTP did not show an association with ER, PR, or HER2 expression. Pregnancy in the third trimester was associated with the induction of TP- and not FTP-reactive autoantibodies (=0.018). The reactivity of BrC sera with placental proteins was found to be independent of gravidity or abortion. BrC sera showed a very strong and specific pattern of reactivity with scattered cells beneath the syncytiotrophoblast layer. Our results reinforce the concept of the coevolution of placentation and cancer and shed light on the future clinical application of the placental proteome for the non-invasive early detection and treatment of cancer.

In utero origin of myelofibrosis presenting in adult monozygotic twins

The latency between acquisition of an initiating somatic driver mutation by a single-cell and clinical presentation with cancer is largely unknown. We describe a remarkable case of monozygotic twins presenting with CALR mutation-positive myeloproliferative neoplasms (MPNs) (aged 37 and 38 years), with a clinical phenotype of primary myelofibrosis. The CALR mutation was absent in T cells and dermal fibroblasts, confirming somatic acquisition. Whole-genome sequencing lineage tracing revealed a common clonal origin of the CALR-mutant MPN clone, which occurred in utero followed by twin-to-twin transplacental transmission and subsequent similar disease latency. Index sorting and single-colony genotyping revealed phenotypic hematopoietic stem cells (HSCs) as the likely MPN-propagating cell. Furthermore, neonatal blood spot analysis confirmed in utero origin of the JAK2V617F mutation in a patient presenting with polycythemia vera (aged 34 years). These findings provide a unique window into the prolonged evolutionary dynamics of MPNs and fitness advantage exerted by MPN-associated driver mutations in HSCs.

Cancer Susceptibility as a Cost of Reproduction and Contributor to Life History Evolution

Reproduction is one of the most energetically demanding life-history stages. As a result, breeding individuals often experience trade-offs, where energy is diverted away from maintenance (cell repair, immune function) toward reproduction. While it is increasingly acknowledged that oncogenic processes are omnipresent, evolving and opportunistic entities in the bodies of metazoans, the associations among reproductive activities, energy expenditure, and the dynamics of malignant cells have rarely been studied. Here, we review the diverse ways in which age-specific reproductive performance (e.g., reproductive aging patterns) and cancer risks throughout the life course may be linked via trade-offs or other mechanisms, as well as discuss situations where trade-offs may not exist. We argue that the interactions between host–oncogenic processes should play a significant role in life-history theory, and suggest some avenues for future research.

Lessons from transmissible cancers for immunotherapy and transplant

The emergence of horizontal transmission of cancer between vertebrates is an issue that interests scientists and medical society. Transmission requires: (i) a mechanism by which cancer cells can transfer to another organism and (ii) a repressed immune response on the part of the recipient. Transmissible tumors are unique models to comprehend the responses and mechanisms mediated by the major histocompatibility complex (MHC), which can be transposed for transplant biology. Here, we discuss the mechanisms involved in immune-mediated tissue rejection, making a parallel with transmissible cancers. We also discuss cellular and molecular mechanisms involved in cancer immunotherapy and anti-rejection therapies.

Non-invasive prenatal testing suggesting a maternal malignancy: What do we tell the prospective parents in Belgium?

Cancer is diagnosed in one in 1000 to 1500 pregnancies. Most frequently encountered malignancies during pregnancy are breast cancer, hematological cancer, cervical cancer and malignant melanoma. Maternal cancer is associated with an increased risk of IUGR and preterm labor, especially in patients with systemic disease or those receiving chemotherapy during pregnancy, requiring a high-risk obstetrical follow-up. Fetal aneuploidy screening by non-invasive prenatal testing (NIPT) can lead to the incidental identification of copy number alterations derived from non-fetal cell-free DNA (cfDNA), as seen in certain cases of maternal malignancy. The identification of tumor-derived cfDNA requires further clinical, biochemical, radiographic and histological investigations to confirm the diagnosis. In such cases, reliable risk estimation for fetal trisomy 21, 18 and 13 is impossible. Therefore, invasive testing should be offered when ultrasonographic screening reveals an increased risk for chromosomal anomalies, or when a more accurate test is desired. When the fetal karyotype is normal, long term implications for the fetus refer to the consequences of the maternal disease and treatment during pregnancy. This manuscript addresses parental questions when NIPT suggests a maternal malignancy. Based on current evidence and our own experience, a clinical management scheme in a multidisciplinary setting is proposed.

Vaginal Transmission of Cancer from Mothers with Cervical Cancer to Infants

Two cases of pediatric lung cancer (in 23-month-old and 6-year-old boys) resulting from mother-to-infant transmission of uterine cervical tumors were incidentally detected during routine next-generation sequencing of paired samples of tumor and normal tissue. Spontaneous regression of some lesions in the first child and slow growth of the tumor mass in the second child suggested the existence of alloimmune responses against the transmitted tumors. Immune checkpoint inhibitor therapy with nivolumab led to a strong regression of all remaining tumors in the first child. (Funded by the Japan Agency for Medical Research and Development and others; TOP-GEAR UMIN Clinical Trials Registry number, UMIN000011141.).

Ovarian Cancer and Pregnancy-A Current Problem in Perinatal Medicine: A Comprehensive Review

The frequency of concomitant adnexal tumors in pregnancy is reported to be at 0.15-5.7%, while ovarian cancer complicates 1 in 15,000 to 1 in 32,000 pregnancies, being the second most common gynecologic cancer diagnosed during pregnancy. The aim of this review is to discuss the problem of ovarian cancer complicating pregnancy and the current recommendations for diagnostics and treatment, with an emphasis on the risk to the fetus. A detailed analysis of the literature found in the PubMed and MEDLINE databases using the keywords "ovarian cancer", "ovarian malignancy", "adnexal masses", "ovarian tumor" and "pregnancy" was performed. There were no studies on a large series of pregnant women treated for ovarian malignancies and the management has not been well established. The diagnostics and therapeutic procedures need to be individualized with respect to the histopathology of the tumor, its progression, the gestational age at the time of diagnosis and the mother's decisions regarding pregnancy preservation. The multidisciplinary cooperation of specialists in perinatal medicine, gynecological oncology, chemotherapy, neonatology and psychology seems crucial in order to obtain the best possible maternal and neonatal outcomes.

Transmissible cancers and the evolution of sex under the Red Queen hypothesis

The predominance of sexual reproduction in eukaryotes remains paradoxical in evolutionary theory. Of the hypotheses proposed to resolve this paradox, the 'Red Queen hypothesis' emphasises the potential of antagonistic interactions to cause fluctuating selection, which favours the evolution and maintenance of sex. Whereas empirical and theoretical developments have focused on host-parasite interactions, the premises of the Red Queen theory apply equally well to any type of antagonistic interactions. Recently, it has been suggested that early multicellular organisms with basic anticancer defences were presumably plagued by antagonistic interactions with transmissible cancers and that this could have played a pivotal role in the evolution of sex. Here, we dissect this argument using a population genetic model. One fundamental aspect distinguishing transmissible cancers from other parasites is the continual production of cancerous cell lines from hosts' own tissues. We show that this influx dampens fluctuating selection and therefore makes the evolution of sex more difficult than in standard Red Queen models. Although coevolutionary cycling can remain sufficient to select for sex under some parameter regions of our model, we show that the size of those regions shrinks once we account for epidemiological constraints. Altogether, our results suggest that horizontal transmission of cancerous cells is unlikely to cause fluctuating selection favouring sexual reproduction. Nonetheless, we confirm that vertical transmission of cancerous cells can promote the evolution of sex through a separate mechanism, known as similarity selection, that does not depend on coevolutionary fluctuations.

Concordance for clonal hematopoiesis is limited in elderly twins

Although acquisition of leukemia-associated somatic mutations by 1 or more hematopoietic stem cells is inevitable with advancing age, its consequences are highly variable, ranging from clinically silent clonal hematopoiesis (CH) to leukemic progression. To investigate the influence of heritable factors on CH, we performed deep targeted sequencing of blood DNA from 52 monozygotic (MZ) and 27 dizygotic (DZ) twin pairs (aged 70-99 years). Using this highly sensitive approach, we identified CH (variant allele frequency ≥0.5%) in 62% of individuals. We did not observe higher concordance for CH within MZ twin pairs as compared with that within DZ twin pairs, or to that expected by chance. However, we did identify 2 MZ pairs in which both twins harbored identical rare somatic mutations, suggesting a shared cell of origin. Finally, in 3 MZ twin pairs harboring mutations in the same driver genes, serial blood samples taken 4 to 5 years apart showed substantial twin-to-twin variability in clonal trajectories. Our findings propose that the inherited genome does not exert a dominant influence on the behavior of adult CH and provide evidence that CH mutations may be acquired in utero.

Gynecologic cancers in pregnancy: guidelines based on a third international consensus meeting

We aimed to provide comprehensive protocols and promote effective management of pregnant women with gynecological cancers. New insights and more experience have been gained since the previous guidelines were published in 2014. Members of the International Network on Cancer, Infertility and Pregnancy (INCIP), in collaboration with other international experts, reviewed existing literature on their respective areas of expertise. Summaries were subsequently merged into a manuscript that served as a basis for discussion during the consensus meeting. Treatment of gynecological cancers during pregnancy is attainable if management is achieved by collaboration of a multidisciplinary team of health care providers. This allows further optimization of maternal treatment, while considering fetal development and providing psychological support and long-term follow-up of the infants. Nonionizing imaging procedures are preferred diagnostic procedures, but limited ionizing imaging methods can be allowed if indispensable for treatment plans. In contrast to other cancers, standard surgery for gynecological cancers often needs to be adapted according to cancer type and gestational age. Most standard regimens of chemotherapy can be administered after 14 weeks gestational age but are not recommended beyond 35 weeks. C-section is recommended for most cervical and vulvar cancers, whereas vaginal delivery is allowed in most ovarian cancers. Breast-feeding should be avoided with ongoing chemotherapeutic, endocrine or targeted treatment. More studies that focus on the long-term toxic effects of gynecologic cancer treatments are needed to provide a full understanding of their fetal impact. In particular, data on targeted therapies that are becoming standard of care in certain gynecological malignancies is still limited. Furthermore, more studies aimed at the definition of the exact prognosis of patients after antenatal cancer treatment are warranted. Participation in existing registries (www.cancerinpregnancy.org) and the creation of national tumor boards with multidisciplinary teams of care providers (supplementary Box S1, available at Annals of Oncology online) is encouraged.

Transmissible cancer and the evolution of sex

The origin and subsequent maintenance of sex and recombination are among the most elusive and controversial problems in evolutionary biology. Here, we propose a novel hypothesis, suggesting that sexual reproduction not only evolved to reduce the negative effects of the accumulation of deleterious mutations and processes associated with pathogen and/or parasite resistance but also to prevent invasion by transmissible selfish neoplastic cheater cells, henceforth referred to as transmissible cancer cells. Sexual reproduction permits systematic change of the multicellular organism's genotype and hence an enhanced detection of transmissible cancer cells by immune system. Given the omnipresence of oncogenic processes in multicellular organisms, together with the fact that transmissible cancer cells can have dramatic effects on their host fitness, our scenario suggests that the benefits of sex and concomitant recombination will be large and permanent, explaining why sexual reproduction is, despite its costs, the dominant mode of reproduction among eukaryotes.

Open questions: knowing who's who in multicellular animals is not always as simple as we imagine

The ability of certain tumor cells of mammals and molluscs to spread from the original host to others reopens the question of distinguishing self from non-self. It is part of a wider phenomenon of cellular parasitism and cell chimerism including germ cells.