Noninvasive Prenatal Test Results Indicative of Maternal Malignancies: A Nationwide Genetic and Clinical Follow-Up Study

The impact of confined placental mosaicism on prenatal cell-free DNA screening: Insights from a monocentric study of 99 cases

INTRODUCTION

Confined placental mosaicism (CPM) is thought to be one of the main sources of false-positive prenatal cell-free DNA (cfDNA) screening results, but extensive and systematic studies to prove this statement are limited. We evaluate the contribution of CPM to false-positive prenatal cfDNA screening results in the largest cohort published to date.

METHOD

We systematically offered postnatal analysis on placenta and umbilical cord to women who had a negative amniocentesis following a positive prenatal cfDNA screening result. A standardized protocol was used in which (when available) biopsies were taken at five locations in the placenta and umbilical cord.

RESULTS

We analyzed a series of 99 placentas. CPM could be confirmed in 32.3 % of cases (32/99). CPM was detected across all subtypes of chromosomal aberrations (common and rare autosomal trisomies, sex chromosome abnormalities, copy number variations and autosomal monosomies). A lower detection rate was present in umbilical cord biopsies in comparison with placental biopsies. When comparing different sections of the placenta, no clear difference could be observed with regard to the probability of CPM being present nor to the grade of mosaicism.

DISCUSSION

We confirm an important role for CPM in explaining false-positive prenatal cfDNA screening results. Placental regional differences are common. Given its limited clinical relevance, we do however not advocate placental studies in a diagnostic setting.

Prenatal Genome-Wide Cell-Free DNA Screening: Three Years of Clinical Experience in a Hospital Prenatal Diagnostic Unit in Spain

Genome-wide prenatal cell-free DNA (cfDNA) screening can be used to screen for a wide range of fetal chromosomal anomalies in pregnant patients. In this study, we describe our clinical experience with a genome-wide cfDNA assay in screening for common trisomies, sex chromosomal aneuploidies (SCAs), rare autosomal aneuploidies (RAAs), and copy-number variations (CNVs) in about 6000 patients over a three-year period at our hospital's Prenatal Diagnostic Unit in Spain. Overall, 204 (3.3%) patients had a high-risk call, which included 76 trisomy 21, 21 trisomy 18, 7 trisomy 13, 29 SCAs, 31 RAAs, 31 CNVs, and 9 cases with multiple anomalies. The diagnostic outcomes were obtained for the high-risk cases when available, allowing for the calculation of positive predictive values (PPVs). Calculated PPVs were 95.9% for trisomy 21, 77.8% for trisomy 18, 66.7% for trisomy 13, 10.7% for RAAs, and 10.7% for CNVs. Pregnancy and birth outcomes were also collected for the majority of RAA and CNV cases. Adverse perinatal outcomes for some of these cases included preeclampsia, fetal growth restriction, preterm birth, reduced birth weight, and major congenital structural abnormalities. In conclusion, our study showed strong performance for genome-wide cfDNA screening in a large cohort of pregnancy patients in Spain.

Comprehensive Recommendations for the Clinical Management of Pregnant Women With Noninvasive Prenatal Test Results Suspicious of a Maternal Malignancy

In this article, we defined comprehensive recommendations for the clinical follow-up of pregnant women with a malignancy-suspicious NIPT result, on the basis of the vast experience with population-based NIPT screening programs in two European countries complemented with published large data sets. These recommendations provide a tool for classifying NIPT results as malignancy-suspicious, and guide health care professionals in structured clinical decision making for the diagnostic process of pregnant women who receive such a malignancy-suspicious NIPT result.

Breast cancer during pregnancy-The oncologist's point of view

Breast cancer is the most common malignancy diagnosed during or directly after pregnancy. Differences in pathogenesis and prognosis identify two distinct patient groups, those with breast cancer during pregnancy and those with postpartum breast cancer which, for reasons not completely understood, is associated with worse outcomes. Compared with breast cancer in the non-pregnant patient, several limitations in terms of both local and systemic therapy are applied to limit fetal harm. Treatment is nevertheless delivered with curative intent, therefore avoiding harmful delays in therapy initiation, unnecessary therapy de-escalation or chemotherapy dose modifications is strongly recommended. In this short commentary, we briefly review current evidence and treatment guidelines and provide recommendations for optimal oncologic management of pregnancy-related breast cancer.

Placental, maternal, fetal, and technical origins of false-positive cell-free DNA screening results

The introduction of noninvasive prenatal testing has resulted in substantial reductions to previously accepted false-positive rates of prenatal screening. Despite this, the possibility of false-positive results remains a challenging consideration in clinical practice, particularly considering the increasing uptake of genome-wide noninvasive prenatal testing, and the subsequent increased proportion of high-risk results attributable to various biological events besides fetal aneuploidy. Confined placental mosaicism, whereby chromosome anomalies exclusively affect the placenta, is perhaps the most widely accepted cause of false-positive noninvasive prenatal testing. There remains, however, a substantial degree of ambiguity in the literature pertaining to the clinical ramifications of confined placental mosaicism and its potential association with placental insufficiency, and consequentially adverse pregnancy outcomes including fetal growth restriction. Other causes of false-positive noninvasive prenatal testing include vanishing twin syndrome, in which the cell-free DNA from a demised aneuploidy-affected twin triggers a high-risk result, technical failures, and maternal origins of abnormal cell-free DNA such as uterine fibroids or unrecognized mosaicisms. Most concerningly, maternal malignancies are also a documented cause of false-positive screening results. In this review, we compile what is currently known about the various causes of false-positive noninvasive prenatal testing.

Diagnostic, Management, and Neonatal Outcomes of Colorectal Cancer during Pregnancy: Two Case Reports, Systematic Review of Literature and Metanalysis

OBJECTIVE

Colorectal cancer (CRC) during pregnancy is a rare occurrence, with a reported incidence of 0.8 cases per 100,000 pregnancies. Managing CRC during pregnancy poses substantial challenges for clinicians: the diagnosis is often complicated and delayed due to symptom overlap with pregnancy-related manifestations, and medical imaging is constrained by safety concerns for the foetus.

METHODS

This article presents two cases of advanced CRC diagnosed and managed during pregnancy. Additionally, we conducted a systematic review of the literature to assess diagnostic and prognostic factors involved in CRC in pregnant individuals. The systematic review, with pre-registration and approval through Prospero, involved an extensive search of medical databases (Pubmed, Web of Science, Scopus and Scholar) and statistical analysis using t-test for continuous variables and chi square for dichotomous variables.

RESULTS

A total of 1058 studies were identified. After applying exclusion criteria, sixty-six studies were included. Women whose initial symptoms were severe abdominal pain not responsive to common medical treatments and constipation (acute abdomen) had a mean gestational age at delivery lower than those who presented with paucisymptomatic onset. In our study groups, women who underwent chemotherapy during pregnancy had a higher mean gestational age at delivery and did not experience worse neonatal outcomes compared to those who did not undergo chemotherapy.

CONCLUSIONS

CRC during pregnancy poses unique diagnostic and therapeutic challenges. Collaborative efforts among various medical disciplines are essential to manage CRC during pregnancy.

Evaluation of Circulating Tumor DNA as a Liquid Biomarker in Uveal Melanoma

Purpose

Uveal melanoma (UM) has a high propensity to metastasize. Prognosis is associated with specific driver mutations and copy number variations (CNVs), but limited primary tumor tissue is available for molecular characterization due to eye-sparing irradiation treatment. This study aimed to assess the rise in circulating tumor DNA (ctDNA) levels in UM and evaluate its efficacy for CNV-profiling of patients with UM.

Methods

In a pilot study, we assessed ctDNA levels in the blood of patients with UM (n = 18) at various time points, including the time of diagnosis (n = 13), during fractionated stereotactic radiotherapy (fSRT) treatment (n = 6), and upon detection of metastatic disease (n = 13). Shallow whole-genome sequencing (sWGS) combined with in silico size-selection was used to identify prognostically relevant CNVs in patients with UM (n = 26) from peripheral blood retrieved at the time of diagnosis (n = 9), during fSRT (n = 5), during post-treatment follow-up (n = 4), metastasis detection (n = 6), and metastasis follow-up (n = 4).

Results

A total of 34 patients had blood analyzed for ctDNA detection (n = 18) and/or CNV analysis (n = 26) at various time points. At the time of diagnosis, 5 of 13 patients (38%) had detectable ctDNA (median = 0 copies/mL). Upon detection of metastatic disease, ctDNA was detected in 10 of 13 patients (77%) and showed increased ctDNA levels (median = 24 copies/mL, P < 0.01). Among the six patients analyzed during fSRT, three (50%) patients had detectable ctDNA at baseline and three of six (50%) patients had undetectable levels of ctDNA. During the fSRT regimen, ctDNA levels remained unchanged (P > 0.05). The ctDNA fractions were undetectable to low in localized disease, and sWGS did not elucidate chromosome 3 status from blood samples. However, in 7 of 10 (70%) patients with metastases, the detection of chromosome 3 loss corresponded to the high metastatic-risk class.

Conclusions

The rise in ctDNA levels observed in patients with UM harboring metastases suggests its potential utility for CNV profiling. These findings highlight the potential of using ctDNA for metastasis detection and patient inclusion in therapeutic studies targeting metastatic UM.

Non-invasive prenatal testing: when results suggests maternal cancer

It is now well-established that non-invasive prenatal testing (NIPT), originally designed to screen cell-free DNA (cfDNA) in maternal blood for the presence of common fetal trisomies, can lead to incidental detection of occult maternal malignancies. Retrospective evaluations have demonstrated that the detection of multiple copy number alterations in cfDNA is particularly suggestive of an incipient tumor and that cancer detection rates not only depend on tumor biology but also on applied NIPT technologies and downstream diagnostic investigations. Since the identification of a maternal cancer in pregnancy has implications for both woman and the unborn child, prospective studies are needed to provide evidence on best clinical practices and on clinical utility in terms of patient outcomes.

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.

Chorionic Villous Testing Versus Amniocentesis After Abnormal Noninvasive Prenatal Testing

In the setting of a normal first-trimester ultrasound, an amniocentesis may be a better option than chorionic villous sampling for invasive diagnostic testing after a cell-free DNA high risk for trisomy 13, given the high rates of confined placental mosaicism. In unaffected fetuses, other evaluations should be considered depending on the cell-free DNA results, including maternal karyotyping for monosomy X, uniparental disomy testing for chromosomes with imprinted genes, serial growth scans for trisomy 16, and a workup for maternal malignancy for multiple aneuploidies or autosomal monosomy.

Noninvasive Prenatal Testing Using Circulating DNA and RNA: Advances, Challenges, and Possibilities

Prenatal screening using sequencing of circulating cell-free DNA has transformed obstetric care over the past decade and significantly reduced the number of invasive diagnostic procedures like amniocentesis for genetic disorders. Nonetheless, emergency care remains the only option for complications like preeclampsia and preterm birth, two of the most prevalent obstetrical syndromes. Advances in noninvasive prenatal testing expand the scope of precision medicine in obstetric care. In this review, we discuss advances, challenges, and possibilities toward the goal of providing proactive, personalized prenatal care. The highlighted advances focus mainly on cell-free nucleic acids; however, we also review research that uses signals from metabolomics, proteomics, intact cells, and the microbiome. We discuss ethical challenges in providing care. Finally, we look to future possibilities, including redefining disease taxonomy and moving from biomarker correlation to biological causation.

Patients' perspectives on prenatal screening results that suggest maternal cancer: A qualitative analysis

OBJECTIVE

To explore patient perspectives after receiving non-invasive prenatal testing (NIPT) results that suggest maternal cancer.

METHODS

Individuals who received non-reportable or discordant NIPT results during pregnancy and enrolled in a study were interviewed prior to and after receiving the outcome of their clinical evaluation for cancer. Interviews were independently coded by two researchers and analyzed thematically.

RESULTS

Forty-nine participants were included. Three themes were identified: 1) limited pre-test awareness of maternal incidental findings caused considerable confusion for participants, whose initial concerns focused on their babies; 2) providers' communication influenced how participants perceived their risk of cancer and the need to be evaluated; and 3) participants perceived value in receiving maternal incidental findings from NIPT despite any stress it caused during their pregnancy.

CONCLUSION

Participants viewed the ability to detect occult malignancy as an added benefit of NIPT and felt strongly that these results should be disclosed. Obstetric providers need to be aware of maternal incidental findings from NIPT, inform pregnant people of the potential to receive these results during pre-test counseling, and provide accurate and objective information during post-test counseling.

CLINICAL TRIAL REGISTRATION

Incidental Detection of Maternal Neoplasia Through Non-Invasive Cell-Free DNA Analysis (IDENTIFY), a Natural History Study, NCT4049604.

A Novel Paradigm for Non-Invasive Prenatal Genetic Screening: Trophoblast Retrieval and Isolation from the Cervix (TRIC)

As the prevalence of pregnancies with advanced maternal age increases, the risk of fetal chromosomal abnormalities is on the rise. Therefore, prenatal genetic screening and diagnosis have become essential elements in contemporary obstetrical care. Trophoblast retrieval and isolation from the cervix (TRIC) is a non-invasive procedure that can be utilized for prenatal genetic diagnosis. The method involves the isolation of fetal cells (extravillous trophoblasts) by transcervical sampling; along with its non-invasiveness, TRIC exhibits many other advantages such as its usefulness in early pregnancy at 5 weeks of gestation, and no interference by various fetal and maternal factors. Moreover, the trophoblast yields from TRIC can provide valuable information about obstetrical complications related to abnormal placentation even before clinical symptoms arise. The standardization of this clinical tool is still under investigation, and the upcoming advancements in TRIC are expected to meet the increasing need for a safe and accurate option for prenatal diagnosis.

Immunochemotherapy for life-threatening haematological malignancies in pregnancy: a systematic review of the literature and cross-sectional analysis of clinical trial eligibility

The management of potentially life-threatening malignancies in pregnancy is complicated by a lack of robust safety and efficacy evidence. This data shortage stems from a historical exclusion of women of childbearing potential from prospective clinical trials due to concerns around potential teratogenicity and toxicity of investigational agents. We conducted a systematic review of published data on immunochemotherapeutic treatment of life-threatening haematological malignancies in pregnancy between 2010 and 2022, and the maternal and neonatal outcomes. We then performed a cross-sectional observational study of clinical trial protocols on ClinicalTrials.gov, between 2016 and 2022, recruiting women of childbearing potential with potentially life-threatening haematological malignancies, collecting trial demographic data, and documenting whether pregnant or lactating women were explicitly excluded, along with the type and duration of contraception required for women of childbearing potential. We included 17 studies for analysis in our systematic review. A total of 595 women were treated with immunochemotherapy during pregnancy, with a median age of 29 years (range 14-48). Of these, 81 women (14%) were treated in the first trimester, and 514 (86%) were treated in the second and third trimesters collectively. In total, 68 trials for acute myeloid leukaemia, acute lymphocytic leukaemia, high-grade non-Hodgkin lymphoma, and Hodgkin lymphoma (40%, 26%, 21%, and 13%, respectively) were included in our ClinicalTrials.gov analysis. Most protocols (66 [97%]) explicitly excluded pregnant women, with 40 (69%) not providing a rationale for exclusion. The potential harm to the fetus from anti-cancer therapy has historically been given greater moral precedence than a pregnant woman's autonomy. This pattern is reflected in the lack of rigorous evidence for immunochemotherapy in pregnancy and a universal exclusion of pregnant and lactating women from clinical trial protocols in this study. Nonetheless, the administration of systemic chemotherapy in the second and third trimesters was not associated with an increased rate of congenital malformations or perinatal mortality in our systematic review cohort, with maternal outcomes broadly comparable to those of the non-pregnant population.

Patient-Centered Care in the Management of Cancer During Pregnancy

The management of cancer during pregnancy requires a patient-centered, multidisciplinary approach to balance maternal and fetal well-being given the rarity of this clinical scenario and lack of substantial data. Involvement of oncology and nononcology medical specialists and ethical, legal, and psychosocial supports, as needed, is instrumental in navigating the complexities of care for this patient population. Critical periods of fetal development and physiological changes in pregnancy must be considered when planning diagnostic and therapeutic approaches during pregnancy. The complexity of symptom recognition and interventional approaches contributes to diagnostic delays of cancers during pregnancy. Ultrasound and whole-body diffusion-weighted magnetic resonance imaging are safe throughout pregnancy. Surgery can be safely performed throughout pregnancy, with the early second trimester preferred for intra-abdominal surgery. Chemotherapy can be safely administered after 12-14 weeks of gestation until 1-3 weeks before the anticipated delivery. Most targeted and immunotherapeutic agents are contraindicated during pregnancy because of limited data. Pelvic radiation during pregnancy is absolutely contraindicated, while if radiation to the upper body is needed, administration should only be considered early in pregnancy. To ensure that the total cumulative fetal exposure to ionizing radiation does not exceed 100 mGy, early inclusion of the radiology team in the care plan is required. Closer prenatal monitoring is recommended for maternal and fetal treatment-related toxicities. Delivery before 37 weeks of gestation should be avoided if possible, and vaginal delivery is preferred unless obstetrically indicated or specific clinical scenarios. Postpartum, breastfeeding should be discussed, and the neonate should receive blood work to assess for acute toxicities with follow-up arranged for long-term monitoring.

Noninvasive prenatal screening and maternal malignancy: role of imaging

Noninvasive prenatal screening (NIPS) tests for fetal chromosomal anomalies through maternal blood sampling. It is becoming widely available and standard of care for pregnant women in many countries. It is performed in the first trimester of pregnancy, usually between 9 and 12 weeks. Fragments of fetal cell-free deoxyribonucleic acid (DNA) floating in maternal plasma are detected and analyzed by this test to assess for chromosomal aberrations. Similarly, maternal tumor-derived cell-free DNA (ctDNA) released from the tumor cells also circulates in the plasma. Hence, the presence of genomic anomalies originating from maternal tumor-derived DNA may be detected on the NIPS-based fetal risk assessment in pregnant patients. Presence of multiple aneuploidies or autosomal monosomies are the most commonly reported NIPS abnormalities detected with occult maternal malignancies. When such results are received, the search for an occult maternal malignancy begins, in which imaging plays a crucial role. The most commonly detected malignancies via NIPS are leukemia, lymphoma, breast and colon cancers. Ultrasound is a reasonable radiation-free modality for imaging during pregnancy, specially when there are localizing symptoms or findings, such as palpable lumps. While there are no consensus guidelines on the imaging evaluation for these patients, when there are no localizing symptoms or clinically palpable findings, whole body MRI is recommended as the radiation-free modality of choice to search for an occult malignancy. Based on clinical symptoms, practice patterns, and available resources, breast ultrasound, chest radiographs, and targeted ultrasound evaluations can also be performed initially or as a follow-up for MRI findings. CT is reserved for exceptional circumstances due to its higher radiation dose. This article intends to increase awareness of this rare but stressful clinical scenario and guide imaging evaluation for occult malignancy detected via NIPS during pregnancy.

Maternal Malignancy After Atypical Findings on Single-Nucleotide Polymorphism-Based Prenatal Cell-Free DNA Screening

OBJECTIVE

To evaluate the incidence and clinical outcomes of cell-free DNA results suspicious for maternal malignancy on prenatal cell-free DNA screening with single-nucleotide polymorphism (SNP)-based technology.

METHODS

This retrospective cohort study included data from SNP-based, noninvasive prenatal screening samples from a commercial laboratory from January 2015 to October 2021. Maternal plasma was screened for trisomy 21, 18, and 13; monosomy X; and triploidy. Cases were considered suspicious for maternal malignancy if retrospective bioinformatics and visual inspection of the SNP plot were suggestive of multiple maternal copy number variants across at least two of the tested chromosomes. Clinical follow-up on patients was obtained by contacting individual referring clinician offices by telephone, facsimile, or email.

RESULTS

A total of 2,004,428 noninvasive prenatal screening samples during the study period met criteria for inclusion in the analysis. Of these, 38 samples (0.002% or 1 in 52,748, 95% CI 1:74,539-1:38,430) had SNP-plot results that were suspicious for maternal malignancy. Maternal health outcomes were obtained in 30 of these patients (78.9%); eight were lost to follow-up. Maternal malignancy or suspected malignancy was identified in 66.7% (20/30) of the 30 patients with clinical follow-up provided by the clinic. The most common maternal malignancies were lymphoma (n=10), breast cancer (n=5), and colon cancer (n=3).

CONCLUSION

Results suspicious for maternal malignancy are rare with SNP-based noninvasive prenatal screening (1:53,000), but two thirds of patients who had a noninvasive prenatal screening result concerning for malignancy in this study had a cancer diagnosis. Investigation for malignancy should be recommended for all pregnant patients with this type of result.

FUNDING SOURCE

This study was funded by Natera, Inc.

An 8q24 Gain in Pancreatic Juice Is a Candidate Biomarker for the Detection of Pancreatic Cancer

Secretin-stimulated pancreatic juice (PJ), collected from the duodenum, presents a valuable biomarker source for the (earlier) detection of pancreatic cancer (PC). Here, we evaluate the feasibility and performance of shallow sequencing to detect copy number variations (CNVs) in cell-free DNA (cfDNA) from PJ for PC detection. First, we confirmed the feasibility of shallow sequencing in PJ (n = 4), matched plasma (n = 3) and tissue samples (n = 4, microarray). Subsequently, shallow sequencing was performed on cfDNA from PJ of 26 cases (25 sporadic PC, 1 high-grade dysplasia) and 19 controls with a hereditary or familial increased risk of PC. 40 of the 45 PJ samples met the quality criteria for cfDNA analysis. Nine individuals had an 8q24 gain (oncogene MYC; 23%; eight cases (33%) and one control (6%), p = 0.04); six had both a 2q gain (STAT1) and 5p loss (CDH10; 15%; four cases (7%) and two controls (13%), p = 0.72). The presence of an 8q24 gain differentiated the cases and controls, with a sensitivity of 33% (95% CI 16-55%) and specificity of 94% (95% CI 70-100%). The presence of either an 8q24 or 2q gain with a 5p loss was related to a sensitivity of 50% (95% CI 29-71%) and specificity of 81% (95% CI 54-96%). Shallow sequencing of PJ is feasible. The presence of an 8q24 gain in PJ shows promise as a biomarker for the detection of PC. Further research is required with a larger sample size and consecutively collected samples in high-risk individuals prior to implementation in a surveillance cohort.

Noninvasive prenatal screening (NIPS) for fetal chromosome abnormalities in a general-risk population: An evidence-based clinical guideline of the American College of Medical Genetics and Genomics (ACMG)

PURPOSE

This workgroup aimed to develop an evidence-based clinical practice guideline for the use of noninvasive prenatal screening (NIPS) for pregnant individuals at general risk for fetal trisomy 21, trisomy 18, or trisomy 13 and to evaluate the utility of NIPS for other chromosomal disorders.

METHODS

The NIPS Evidence-Based Guideline Work Group (n = 7) relied on the results from the recent American College of Medical Genetics and Genomics (ACMG) systematic review to form the evidentiary basis of this guideline. Workgroup members used the Grading of Recommendations Assessment, Development, and Evaluation Evidence to Decision framework to draft recommendations. The guideline underwent extensive internal and external peer review with a public comment period before approval by the ACMG Board of Directors.

RESULTS

Evidence consistently demonstrated improved accuracy of NIPS compared with traditional screening methods for trisomies 21, 18, and 13 in singleton and twin gestations. Identification of rare autosomal trisomies and other microdeletion syndromes with NIPS is an emerging area of interest.

CONCLUSION

ACMG strongly recommends NIPS over traditional screening methods for all pregnant patients with singleton and twin gestations for fetal trisomies 21, 18, and 13 and strongly recommends NIPS be offered to patients to screen for fetal sex chromosome aneuploidy.

Clinical impacts of genome-wide noninvasive prenatal testing for rare autosomal trisomy

BACKGROUND

Genome-wide noninvasive prenatal testing identifies several rare autosomal trisomies in the general obstetrical population, but its use is questioned by its low positive predictive value. Furthermore, the origin of rare autosomal trisomies and the clinical effect of reporting them has not been sufficiently investigated. In addition, professional societies express their need for data assessing the clinical use of genome-wide noninvasive prenatal testing for rare autosomal trisomies for years.

OBJECTIVE

This study aimed to investigate the origin of rare autosomal trisomies and the clinical effect of disclosing rare autosomal trisomies in clinical settings.

STUDY DESIGN

Women who received noninvasive prenatal testing between March 2021 and March 2022 were prospectively enrolled. Clinical follow-up and cytogenetic and molecular investigations were performed. Posthoc analysis was performed to investigate the association between placental mosaicism and clinical outcomes.

RESULTS

Overall, 154 rare autosomal trisomies were identified in 89,242 pregnancies (0.17%) through noninvasive prenatal testing. In the 120 cases in which cytogenetic and molecular investigations were carried out, the rare autosomal trisomies were found to originate from true fetal mosaicism (n=5), uniparental disomy (n=5), maternal mosaic trisomy (n=3), maternal malignancy (n=1), and confined placental mosaicism (n=106). Clinical follow-up showed that 40% of all rare autosomal trisomy cases had adverse perinatal outcomes. In women with false-positive noninvasive prenatal testing results originating from confined placental mosaicism, the frequency of adverse perinatal outcomes was 26%. More importantly, the placental mosaicism ratio revealed by noninvasive prenatal testing was significantly higher in women who experienced adverse perinatal outcomes than those who did not (0.688 vs 0.332; P<.001).

CONCLUSION

Women with noninvasive prenatal testing results indicative of rare autosomal trisomies are at risk of adverse perinatal outcomes, and that risk can be stratified using chromosomes and the mosaicism ratio revealed by noninvasive prenatal testing. Our data are valuable for obstetrical caregivers advising a patient with a noninvasive prenatal testing result indicative of a rare autosomal trisomy and a false-positive diagnosis and for managing risks during pregnancy.

Clinicopathologic features, treatment, and prognosis of pregnancy-associated breast cancer

Purpose

To identify the clinicopathological features, treatment, and prognosis of patients with breast cancer, who were diagnosed during and after pregnancy.

Methods

We searched for patients with pregnancy-associated breast cancer (PABC) using the big data query and analysis system of Peking Union Medical College Hospital from between January 1, 2013, and December 31, 2021, and matched each patient with two non-PABC patients by age at diagnosis, year at diagnosis, and tumor stage. The clinicopathologic features, treatment, and outcomes of breast cancer during pregnancy (BC-P) and breast cancer during the first-year post-partum (BC-PP) were examined retrospectively in two case-control studies.

Results

Eighteen BC-P cases, 36 controls for BC-P cases, 62 BC-PP cases, and 124 controls for BC-PP cases were enrolled in our study. The expression of HER-2 and Ki-67 was higher in BC-PP cases than in its controls (P=0.01, 0.018, respectively). Patients with BC-PP were more likely to choose mastectomy than breast-conserving surgery (P=0.001). There were no significant differences in event-free survival (EFS) between patients with BC-P and BC-PP and their controls.

Conclusion

BC-P and BC-PP patients displayed adverse clinicopathological features in our population. However, when matched by age at diagnosis, year of diagnosis, and tumor stage, BC-P and BC-PP patients did not show inferior outcomes to controls, probably due to aggressive multimodality therapy.

Experiences of pregnant women with genome-wide non-invasive prenatal testing in a national screening program

Pregnant women’s perspectives should be included in the dialogue surrounding the expanding offers of non-invasive prenatal testing (NIPT), especially now that technological possibilities are rapidly increasing. This study evaluated women’s experiences with the offer of genome-wide (GW) first-tier NIPT in a national screening program. A nationwide pre-and post-test questionnaire was completed by 473 pregnant women choosing between targeted NIPT (trisomies 21, 18 and 13 only) and GW-NIPT (also other findings) within the Dutch TRIDENT-2 study. Measures included satisfaction, reasons for or against choosing GW-NIPT, anxiety, and opinion on the future scope of NIPT. Most respondents (90.4%) were glad to have been offered the choice between GW-NIPT and targeted NIPT; 76.5% chose GW-NIPT. Main reasons to choose GW-NIPT were ‘wanting as much information as possible regarding the child’s health’ (38.6%) and ‘to be prepared for everything’ (23.8%). Main reasons to choose targeted NIPT were ‘avoiding uncertain results/outcomes’ (33.7%) and ‘not wanting to unnecessarily worry’ (32.6%). Nearly all respondents received a low-risk NIPT result (98.7%). No differences were found in anxiety between women choosing GW-NIPT and targeted NIPT. Most respondents were favorable toward future prenatal screening for a range of conditions, including life-threatening disorders, mental disabilities, disorders treatable in pregnancy and severe physical disabilities, regardless of their choice for GW-NIPT or targeted NIPT. In conclusion, women who chose first-tier NIPT were satisfied with the choice between GW-NIPT and targeted NIPT, and most women were favorable toward a broader future screening offer. Our results contribute to the debate concerning the expansion of NIPT.

Clinical impact of additional findings detected by genome-wide non-invasive prenatal testing: Follow-up results of the TRIDENT-2 study

In the TRIDENT-2 study, all pregnant women in the Netherlands are offered genome-wide non-invasive prenatal testing (GW-NIPT) with a choice of receiving either full screening or screening solely for common trisomies. Previous data showed that GW-NIPT can reliably detect common trisomies in the general obstetric population and that this test can also detect other chromosomal abnormalities (additional findings). However, evidence regarding the clinical impact of screening for additional findings is lacking. Therefore, we present follow-up results of the TRIDENT-2 study to determine this clinical impact based on the laboratory and perinatal outcomes of cases with additional findings. Between April 2017 and April 2019, additional findings were detected in 402/110,739 pregnancies (0.36%). For 358 cases, the origin was proven to be either fetal (n = 79; 22.1%), (assumed) confined placental mosaicism (CPM) (n = 189; 52.8%), or maternal (n = 90; 25.1%). For the remaining 44 (10.9%), the origin of the aberration could not be determined. Most fetal chromosomal aberrations were pathogenic and associated with severe clinical phenotypes (61/79; 77.2%). For CPM cases, occurrence of pre-eclampsia (8.5% [16/189] vs 0.5% [754/159,924]; RR 18.5), and birth weight <2.3rd percentile (13.6% [24/177] vs 2.5% [3,892/155,491]; RR 5.5) were significantly increased compared to the general obstetric population. Of the 90 maternal findings, 12 (13.3%) were malignancies and 32 (35.6%) (mosaic) pathogenic copy number variants, mostly associated with mild or no clinical phenotypes. Data from this large cohort study provide crucial information for deciding if and how to implement GW-NIPT in screening programs. Additionally, these data can inform the challenging interpretation, counseling, and follow-up of additional findings.