Cell-free DNA Testing Research Articles

P-2224. Clinical and Public Health Implications of Tularemia Diagnoses by Microbial Cell-Free DNA Testing

Abstract Background Tularemia is a nationally notifiable disease and Category A potential bioterrorist threat caused by Francisella tularensis. Microbial cell-free DNA (mcfDNA) sequencing is a pathogen-agnostic diagnostic method using human plasma. mcfDNA detections of F. tularensis are not currently included in public health surveillance criteria for a tularemia case and are not automatically reported to public health jurisdictions. We reviewed recent F. tularensis mcfDNA detections to better understand their clinical and public health implications.Table 1.Francisella tularensis diagnostic test results and reported exposure histories among 15 patients with F. tularensis detected by mcfDNA sequencing — United States, 2018–2023. Methods Available residual patient samples, in which F. tularensis mcfDNA were detected by the Karius CLIA certified/CAP accredited laboratory, were sent to the Centers for Disease Control and Prevention (CDC) for F. tularensis testing by PCR. Treating clinicians and local/state public health jurisdictions where these patients lived at the time of testing were invited to complete a survey regarding clinical details and public health reporting.Table 2.Demographic and clinical characteristics of patients with Francisella tularensis detected by microbial cell-free DNA (mcfDNA) testing, as reported by the ordering clinician — United States, 2018–2023. Results During 2018–2023, mcfDNA sequencing detected F. tularensis in 15 patient samples in 6 states. CDC detected F. tularensis by PCR in 4 (31%) of 13 residual samples, all in samples with higher DNA quantities. All invited jurisdictions (n=6) and most clinicians (8/13, 62%) participated in the survey. Most cases (12/15, 80%) were reported to public health; 3 of 12 (25%) were determined not to meet the tularemia surveillance case definition, and only 1 case reported to CDC mentioned mcfDNA results. Among 11 cases with clinical information, tularemia was not suspected before receipt of mcfDNA results in 10 (91%), despite all patients reporting outdoor activities that could increase F. tularensis exposure risk. Other diagnostic tests for tularemia were positive in 7 of 11 (64%) cases; blood cultures were negative in all cases. mcfDNA results changed clinical management in all cases, resulting in antibiotic changes.Figure 1.Cross-sectional computed tomography of the lungs in a patient diagnosed with pneumonic tularemia by microbial cell-free DNA (mcfDNA) testing, showing bilateral moderate pleural effusion and right upper and middle lobe pulmonary nodules. This patient also exhibited nonspecific mediastinal and bilateral axillary lymphadenopathy and typhoidal symptoms. In this case, mcfDNA testing identified Francisella tularensis nearly 50 hours before any conventional testing confirmed the diagnosis and prompted changes in antibiotic therapy and infection prevention efforts to begin. Conclusion mcfDNA appears to be clinically impactful and highly sensitive for diagnosis of tularemia, particularly in febrile patients with consistent exposure history. New diagnostic methods may pose a challenge to public health surveillance and require changes to case definitions and reporting practices to ensure robustness of public health utility and timely prevention efforts.Figure 2.Left medial knee with 3 cm nodular ulcer with purulence and adjacent erythema at location of suspected tick bite in a patient diagnosed with ulceroglandular tularemia by microbial cell-free DNA (mcfDNA) testing. Disclosures Sarah Y. Park, MD, FAAP, Karius, Inc.: employee

P-920. Free-living Ameba Infections Diagnosed by Cell-free DNA Blood Testing – United States, 2018-2023

Abstract Background Free-living amebae (FLA) including Acanthamoeba spp., Balamuthia mandrillaris, and Naegleria fowleri live in soil and water worldwide and cause severe infections in humans. Approximately 15 people in the United States are infected by FLA each year; most do not survive. Early diagnosis and treatment improve outcomes. Targeted testing options for FLA require tissue or cerebrospinal fluid (CSF) and are offered at < 5 laboratories in the U.S., making it challenging to diagnose infections quickly and non-invasively. Detection of FLA infections via cell-free DNA testing of blood (Karius Test®) has increased in recent years. Methods The Centers for Disease Control and Prevention (CDC) maintains a database of confirmed FLA cases reported through the CDC FLA Clinical Consultation Service or national surveillance efforts. This database was used to identify and describe cases in which a Karius Test® first detected an FLA infection. Results In 2018-2023, 9 U.S. FLA infections were diagnosed with Karius Test® and reported to CDC, including 4 Acanthamoeba, 4 Balamuthia, and 1 Naegleria case. These represent 10% of FLA cases reported to CDC in this timeframe (9/93). Four of these cases were reported in 2023 (22% of FLA cases in 2023), an increase over previous years. FLA had not been suspected in 8/9 cases before receiving results. Eight patients presented with meningitis or encephalitis; 1 had only skin findings. FLA diagnoses were subsequently confirmed by other methods in 7/7 cases for which tissue or CSF was available. Duration from hospitalization or symptom onset to Karius Test® result was 5-14 days. One patient was diagnosed postmortem; the others were initiated on anti-amebic therapy. No patients ultimately survived, though 3 patients were treated for several weeks. Conclusion Cell-free DNA testing (Karius Test®) of blood is increasingly being used to diagnose FLA infections. Nearly all patients described were diagnosed by Karius Tests® before FLA infections had been suspected. Early diagnosis can allow early treatment, inform clinical decision-making, and contribute to the further understanding of FLA infections through surveillance. In patients with suspected FLA infections or encephalitis of unknown etiology, Karius Test® may be useful, particularly when tissue or CSF is not available. Disclosures All Authors: No reported disclosures

P-2161. Evaluating the Clinical Utility of Next-Generation Sequencing Cell-Free DNA Testing in Pediatric Patients: A Focus on Medical History

Abstract Background The Karius test is a noninvasive, cell-free next-generation sequencing (NGS) test that can detect over 1,000 pathogens from a single blood sample. Validating the Karius test's useful clinical applications in pediatric patients is necessary to elucidate its benefits and limitations compared to conventional diagnostic testing. This pilot study aims to expand on existing evidence for Karius indications by investigating its utility among pediatric patients with specific underlying diagnoses.Figure 1:Age Distribution of Patients in Sample Methods A retrospective chart review was conducted, consisting of 251 consecutive pediatric patients [03/2018-06/2022] (fig 1) for whom a Karius NGS test was performed at a free-standing 240-bed children’s hospital and affiliated clinic in Central Texas. Statistical analysis was conducted to evaluate whether a child’s underlying diagnosis was associated with clinically useful Karius results. The Karius result was considered clinically useful if it was the first or only diagnostic test used to make the diagnosis, had negative predictive value essential to the plan of care, or contributed to changes in the antimicrobial regimen. Underlying diagnoses were categorized into ten groups (fig 2). Statistical analysis was conducted using R software via Pearson’s Chi-Squared Test and Fischer’s Exact Test.Figure 2:Distribution of Underlying Diagnosis in Sample Results Evaluation of underlying diagnoses and the clinical usefulness of the Karius test revealed a significant association only for patients with an oncologic diagnosis (p=0.038) (Fig 3).Figure 3:Underlying Diagnosis and Reason Karius Result Deemed Clinically Useful Conclusion While Karius testing can be useful in specific patients regardless of the underlying diagnosis, this analysis found the most significant utility among patients with an oncology diagnosis. Further investigation through larger sample sizes and prospective designs is essential to validate and extend these findings, shedding light on cost-effectiveness and patient outcomes. Disclosures All Authors: No reported disclosures

Impact of Race/Ethnicity on Clinical and Genomic Characteristics, Trial Participation, and Genotype-Matched Therapy among Patients with Metastatic Breast Cancer.

Race/ethnicity may affect outcomes in metastatic breast cancer (MBC) due to biological and social determinants. We evaluated the impact of race/ethnicity on clinical, socioeconomic, and genomic characteristics, clinical trial participation, and receipt of genotype-matched therapy among patients with MBC. A retrospective study of patients with MBC who underwent cell-free DNA testing (cfDNA, Guardant360â, 74 gene panel) between 11/2016 and 11/2020 was conducted. Receipt of genotype-matched therapy targeted at a cfDNA actionable mutation was determined. Pearson's chi-squared and Wilcoxon rank-sum tests were used to compare categorical and continuous variables between groups. Multivariable logistic regression was used to assess the association of race and receiving matched therapy. 425 patients with MBC and cfDNA results were identified (White: 369, Black: 27, Hispanic 15, and Asian 14). White patients traveled further for cancer care than other groups (p<0.001). White patients had the highest rates of commercial insurance, Black patients had the highest rates of state-supported insurance, and Asian patients had the highest uninsured rates (p<0.001). Clinical trial enrollment did not differ by race/ethnicity (p=0.34). The proportion of patients with ≥1 actionable mutation in cfDNA did not vary by race/ethnicity (p=0.18). The highest rates of matched therapy were observed in White patients (p<0.001). After multivariable logistic regression adjusting for subtype, commercial vs. other insurance, Charlson comorbidity index, and distance to center, White patients remained more likely to receive matched therapy (p=0.024). Racial/ethnic minority patients were less likely to receive matched therapy. Further research is needed to identify barriers to precision medicine.

The evolution of cell-free fetal DNA testing: expanded non-invasive prenatal testing and its effect on target populations.

To evaluate the clinical performance of expanded non-invasive prenatal testing (NIPT-plus) in screening for fetal chromosome aneuploidy and copy number variations (CNVs) among pregnant women with different risk factors to investigate how the target population of cell-free fetal DNA may change in NIPT-plus. The clinical data, test results, confirmatory invasive testing outcomes, and follow-up results of 6,220 pregnant women who underwent NIPT-plus were re-viewed. The performance indicators of the positive predictive value (PPV), positive rate (PR), specificity, and sensitivity in screening for common trisomies, sex chromosomal abnormalities (SCAs), rare autosomal aneuploidies (RAAs), and CNVs were calculated. The PR or PPV of NIPT-plus for screening chromosome aneuploidy and CNVs in women of varying ages, risk factors, and clinical indications were determined. The PRs of common trisomies, SCAs, RAAs, and CNVs in NIPT-plus were 0.71, 0.45, 0.32, and 0.59%, respectively, with 100% sensitivity and specificities ranging from 99.69 to 99.87%. The PPVs were 80.95, 30.77, 13.33, and 44.12%, respectively. The high-risk group had higher PRs and PPVs for chromosome aneuploidy, with no significant difference in screening for CNVs. NIPT-plus showed greater PR for aneuploidy in the older age group than in the younger age group, with no significant differences in CNVs screening. NIPT-plus was able to effectively screen for chromosome aneuploidy and CNVs. The performance of CNVs screening was not significantly different among different risk factors and age groups. The target population for NIPT-plus should include all pregnant women, not just those at high risk.

Advocating a specific risk calculation of trisomy 18 in case of low maternal serum markers during screening for fetal Down syndrome.

In France, legislation concerning pregnancy monitoring only considers screening for Down syndrome (T21), while the contingent introduction of the circulating cell free DNA test (DPNI) also allows screening for trisomies 13 and 18 with similar performances. We retrospectively studied more than 800,000 patients among whom 7971 presented serum markers suggestive of T18 (but without increased risk of T21), of which 438 benefited from NIPT and of a complete pregnancy follow-up. We show that the use of a specific risk calculation for T18 would have improve the relevance of the prescription. The generalization of this calculation would allow an optimization of the management of patients presenting a suggestive biochemical profile without significantly increasing the number of NIPT prescribed.

Discrepancies Between Sex Prediction and Fetal Sex After Prenatal Noninvasive Cell-Free DNA Screening

Abstract In the last 10 years the field of prenatal diagnosis has been significantly reshaped followed by the implementation of noninvasive prenatal cell-free DNA (cfDNA) testing methodologies in clinical practice. Based on a superior performance and higher sensitivity and specificity than the former practice of biochemical markers screening, the American College of Obstetricians and Gynecologists and American College of Medical Genetics and Genomics recommend noninvasive prenatal cfDNA screening for trisomy 21, 18, 13, and sex chromosome aneuploidy to all pregnant people. While cfDNA screening is helpful in risk assessment for the most common autosomal trisomies, cfDNA also provides information about fetal sex chromosomes. Prediction of fetal sex is highly desired by the parents and also useful to healthcare providers for management of pregnancies that are at-risk for X-linked conditions. In fact, utilization of cfDNA screening has resulted in a significant number of referrals to evaluate discordant results for cfDNA sex prediction and appearance of fetal genitalia by prenatal ultrasound scan or at birth raising concerns about the fetus/infant atypical sex development known as a difference in sex development (DSD). In this mini-review, we outline principles and limitations of cfDNA technology, summarize recent findings related to cfDNA test performance in prediction of sex chromosome abnormalities and DSD conditions, define the technical and biological causes of discrepant results, provide recommendations to consolidate efforts by prenatal and clinical management teams in challenging situations, and discuss ethical considerations associated with fetal sex prediction and prenatal DSD diagnosis.

The association between the amount of fetal fraction in cell-free DNA testing and adverse pregnancy outcomes: A cohort study.

Noninvasive perinatal testing is a new method of screening for aneuploidy called cell-free DNA (cfDNA). Fetal fraction (FF) plays a crucial role in assessing the reliability of aneuploidy detection through noninvasive perinatal testing. We aimed to investigate the association between the amount of FF in cfDNA testing and adverse pregnancy outcomes. This cohort study was conducted on 619 singleton pregnant women who were candidates for cfDNA testing and were referred to the perinatology clinics of Shariati hospital and Arash Women's hospital, both affiliated with Tehran University of Medical Sciences, Tehran, Iran from March 2019 to June 2020. The FF was extracted from the cfDNA test results, and the participants were followed until delivery. A total of 619 singleton pregnant women with a mean SD age and FF of 34.4 4.85 and 8.39 3.95, respectively, participated in the study. A significant association between maternal age and FF was not found (p = 0.12). A lower FF was associated with a rise in the incidence of gestational diabetes mellitus (p = 0.02) and a higher FF was associated with a rise in the incidence of fetal growth restriction (p 0.001). However, high or low FF was not associated with pre-eclampsia, premature rupture of membranes, birth weight, or delivery time. No significant association was found between FF and multiple of the median of pregnancy-associated plasma protein-A and free β-human chorionic gonadotropin. The amount of FF may be considered a predictor of certain adverse pregnancy outcomes. Therefore, maternity care should be performed more carefully for women with high or low FF.

Evaluating diagnostic performance: A comparative analysis of cell-free DNA and serological test in hepatic cystic Echinococcosis.

Cystic Echinococcosis (CE) is a zoonotic disease caused by Echinococcus granulosus sensu lato. Diagnosing CE primarily relies on imaging techniques, and there is a crucial need for an objective laboratory test to enhance the diagnostic process. Today, cell-free DNAs (cfDNAs) have gained importance regarding their biomarker potential. This study aims to investigate the diagnostic capabilities of different cfDNA targets (Echinococcus-specific repeat sequences (mgs-4 and mgs-12) and partial fragment of repetitive sequence (EG1 Hae III)) and evaluate their diagnostic effectiveness when compared to a frequently used commercial E.granulosus-specific IgG ELISA. Seventy-six confirmed hepatic CE patients and healthy controls were included in the study. The EG1 Hae III region was assessed using nested PCR, whereas real-time PCR was employed to investigate other cfDNA targets. Analysis of the cfDNA-targeted tests indicated that mgs-4 demonstrated the highest diagnostic efficacy in distinguishing CE patients from healthy controls, achieving a sensitivity of 60.5% (p = 0.002). Combining ELISA with the mgs-4 target led to an increased sensitivity of 72.4% for distinguishing between CE patients and the control group. The sensitivity rates for ELISA and the three cfDNA targets varied among the groups. Active CE patients showed sensitivity rates of 52.9%, 52.9%, 23.5%, and 52.9% for ELISA, mgs-4, mgs-12, and EG1 Hae III assays, respectively. In contrast, inactive cyst patients displayed sensitivity rates of 21.4%, 66.7%, 19%, and 42.9% for the corresponding assays. The mgs-4, either alone or in combination with ELISA, demonstrated notably higher sensitivity values for CE diagnosis in all group comparisons compared to serology.

Utility of Donor Derived Cell Free DNA Testing in Pancreas Transplantation Patients

Utility of Donor Derived Cell Free DNA Testing in Pancreas Transplantation Patients

Rho(D) immune globulin shortage and fetal Rh(D) screening with cell-free DNA.

Despite the availability of Rh(D) immune globulin (RhIg) to prevent alloimmunization in Rh(D)-negative pregnant patients, anti-Rh(D) alloimmunization remains a prevalent cause of hemolytic disease of the fetus and newborn (HDFN). Recent RhIg shortages have caused clinicians and professional societies to identify methods to prioritize RhIg administration. New cell-free DNA (cfDNA) tests to predict fetal red blood cell antigen genotypes have been proposed as an option to prioritize the administration of RhIg to Rh(D)-negative pregnant people. Commercial laboratories offer fetal Rh(D) genotype testing as part of cfDNA screening for fetal aneuploidy. Studies indicate that these tests have a high sensitivity and specificity for the detection of fetal Rh(D) status. Considering the current RhIg shortage, the American College of Obstetricians & Gynecologists (ACOG) suggests that utilizing cfDNA tests to determine fetal Rh(D) status is a reasonable approach to prioritize RhIg administration when supply is limited. cfDNA screening for fetal Rh(D) status is a reasonable approach to triage the administration of RhIg in the setting of the current RhIg shortage. Utilization of cfDNA screening for fetal Rh(D) and other red blood cell antigen status is likely to increase in routine care. Research, professional society guidance, and education are necessary to ensure well tolerated and equitable utilization.

Chromosomal Mosaicism in the Placenta.

The clinical implications of placental chromosomal mosaicism can be challenging for patients and health care providers. Key considerations include the specific characteristics of the chromosomal abnormality (such as size, gene content, and copy number), the timing of the mosaicism's onset during embryogenesis or fetal development, the types of tissues involved, and the level of mosaicism (the ratio of normal to abnormal cells within those tissues). Genetic counseling can help inform patients about the chances of having a live-born child with a chromosomal abnormality. Each case requires individual assessment to provide accurate guidance. This chapter will explore the clinical implications of detecting mosaicism at 3 critical diagnostic stages: (1) chorionic villus sampling (CVS); (2) amniocentesis; and (3) cell-free DNA (cfDNA) testing.

Clinical Validation of a Prenatal Cell-Free DNA Screening Test for Fetal RHD in a Large U.S. Cohort.

To present a large U.S. clinical validation of a next-generation sequencing-based, noninvasive prenatal cell-free DNA test for fetal RHD. This clinical validation study assessed the performance of a commercially available, next-generation sequencing-based cell-free DNA test for fetal RHD status. Samples that passed quality metrics were included if the patient had a previously reported cell-free DNA result for fetal aneuploidy, maternal RhD-negative serology, newborn RhD serology, and maternal RHD deletion or RHD-CE-D hybrid(r's) genotype. Dizygotic twin pregnancies were excluded. Maternal and fetal RHD genotypes were evaluated with prospective cell-free DNA next-generation sequencing analysis. At the time of analysis, investigators were blinded to fetal RhD status. The cohort consisted of 655 pregnant patients with serologic results for RhD antigen. Patient demographics included a representative distribution of race and ethnicities in the RhD-negative U.S. population (74.0% White, 13.7% Hispanic, 7.0% Black, and 2.1% Asian). Cell-free DNA fetal RHD was not reported in two cases. There were zero false-negative cases; 356 of 356 fetuses were correctly identified as fetal RhD positive (sensitivity 100%, 95% CI, 98.9-100%). Of the 297 RhD-negative fetuses, 295 were correctly identified as RhD negative (specificity 99.3%, 95% CI, 97.6-99.8%). Of the fetuses with a negative RhD phenotype, the cell-free DNA test accurately identified three with the fetal RHD pseudogene (RHDΨ) genotype. Validation of this test in this large U.S. cohort of RhD-negative patients provides data on early and accurate noninvasive prenatal identification of fetal RHD genotype at 9 weeks of gestation or more. This test has the potential to assist patients and clinicians in the prevention and management of RhD alloimmunization.

Abstract IA007: Modulating cfDNA biology to enhance liquid biopsies

Abstract Liquid biopsies could transform cancer care but require higher sensitivity to detect early-stage tumors and minimal residual disease (MRD) and to enable tumor molecular profiling and therapy response monitoring for most patients. In this talk, I will focus on the significant biological bottlenecks upstream of cell-free DNA (cfDNA) testing. I will posit that in many circumstances, insufficient circulating tumor DNA (ctDNA) drawn in a blood tube cannot be overcome by assay technology alone, and that in vivo modulation of cfDNA biology may also be required to enhance liquid biopsies. Inspired by widespread use of diagnostic drugs in other areas of medicine, we sought to create the first “priming agents” for liquid biopsies that could be administered before a blood draw to recover more ctDNA. I will describe two such approaches—a monoclonal antibody against double-stranded DNA and a liposome nanoparticle—that briefly attenuate cfDNA clearance by shielding it from nuclease digestion and cellular uptake. These enabled &amp;gt;10x more ctDNA to be collected when administered within 1-2 hours of a blood draw in mice. This improved the analytical limit of detection for ctDNA testing by &amp;gt;10-fold, provided more complete representation of the tumor genome in each blood sample, and increased the sensitivity for detection of small tumors from &amp;lt;10% to &amp;gt;75% in mice. Envisioning a future where liquid biopsies are optionally enhanced with priming, I will also explore a unique potential pairing with our tumor-informed, whole-genome, mutation enrichment sequencing MRD test called MAESTRO, and how it stands to enable routine ctDNA detection below 1 part per million. Citation Format: Viktor Adalsteinsson. Modulating cfDNA biology to enhance liquid biopsies [abstract]. In: Proceedings of the AACR Special Conference: Liquid Biopsy: From Discovery to Clinical Implementation; 2024 Nov 13-16; San Diego, CA. Philadelphia (PA): AACR; Clin Cancer Res 2024;30(21_Suppl):Abstract nr IA007.

Trastuzumab Deruxtecan in Advanced Solid Tumors With Human Epidermal Growth Factor Receptor 2 Amplification Identified by Plasma Cell-Free DNA Testing: A Multicenter, Single-Arm, Phase II Basket Trial.

HERALD/EPOC1806 was conducted as a multicenter phase II trial assessing trastuzumab deruxtecan (T-DXd) therapy for patients with human epidermal growth factor receptor 2 (HER2)-amplified progressive stage solid tumors detected by cell-free DNA (cfDNA) testing. Patients exhibited advanced solid tumors with HER2 amplification that was identified via next-generation sequencing of cfDNA testing, without the requirement for immunohistochemical HER2 testing. The studied group was administered T-DXd at 5.4 mg/kg once every 3 weeks until onset of disease progression or intolerable toxicity. Overall, 4,734 patients underwent cfDNA testing from December 2019 to January 2022, and 252 demonstrated HER2 amplification. Finally, the study included 62 patients with 16 cancer types with a median baseline plasma HER2 copy number (CN) of 8.55 (range, 2.4-73.9). Confirmed overall response rate (ORR) by investigator assessment was 56.5% (95% CI, 43.3 to 69.0), thus showing a value beyond the 5% threshold. Responses were evaluated for 13 cancer types, including KRAS-mutant colorectal (1/3), PIK3CA-mutant endometrial (5/6), and tissue HER2-negative gastric (1/2) cancers. Plasma HER2 CN above versus below the baseline median value did not differ for impact response; however, clearance of HER2 amplification in cfDNA on cycle 2 day 1 had higher response values compared with persistence. Median progression-free survival and response duration were 7.0 (95% CI, 4.9 to 9.7) and 8.8 (95% CI, 5.8 to 11.2) months, respectively, with the majority of complications being mild to moderate. Interstitial lung diseases were identified in 16 (26%) patients, including 14 patients with grade 1 disease, one patient with grade 2 disease, and one patient with grade 3 disease. T-DXd treatment demonstrated high ORR with durable response in patients with advanced HER2-amplified solid tumors determined with cfDNA testing.

Adopting Non-invasive Approaches into Precision Colorectal Cancer Screening.

Effective screening is essential to reducing CRC incidence and mortality by detecting the disease at early stages and identifying non-invasive precursors. While colonoscopy remains the most sensitive modality to visualize and remove neoplastic lesions thereby reducing CRC and the related death, its high cost and invasive nature limit its widespread use. The fecal immunochemical test (FIT), which offers a non-invasive alternative with higher public acceptance and comparable cost-effectiveness to colonoscopy, has become the preferred screening method in many regions. Newer non-invasive tests, such as multitarget stool DNA or RNA tests, have shown improved sensitivity for CRC and advanced adenomas, although their high costs and lower specificity present challenges for large-scale implementation. Blood-based circulating cell-free DNA test also offer promise but still require optimization to be cost-effective. The heterogeneity of the screening population further complicates the effectiveness of CRC screening programs. Variations in non-communicable disease risk factors, such as metabolic syndrome, lifestyle habits, and comorbidities, can significantly influence CRC risk and screening outcomes. Moreover, diverse screening behaviors, including inconsistent adherence to recommended screening intervals and the interchangeable use of different screening modalities, add complexity to achieving uniform effectiveness across populations. This variability underscores the need for personalized screening strategies that consider individual risk profiles and screening behaviors, as well as the application of cutting-edge technologies such as big data analytics, artificial intelligence, and digital twin approaches to evaluate its effectiveness. This article reviews the current CRC screening strategies, the advantages of non-invasive methods, and the potential of fecal hemoglobin concentration, to tailor screening intervals and improve risk stratification. It also discusses the emerging role of real-world data and advanced technologies in enhancing CRC screening accuracy and effectiveness, particularly in complex real-world scenarios where traditional methods may fall short. Before novel non-invasive approaches, such as ctDNA tests or polygenic risk scores, are validated and proven cost-effective, exploring the clinical utility of FIT and its quantitative measurement in both screening and surveillance by integrating real-world clinical big data seems a feasible direction for achieving sustained development in population screening.

Histiocytosis Advancements Parallel Ophthalmic Innovations. The LXXXI Edward Jackson Memorial Lecture

PurposeTo highlight innovations in ophthalmic oncology through histiocytosis advancements. DesignPerspective and retrospective review. MethodsThe literature outlining the recent advancements in histiocytosis and ocular oncology were reviewed and combined with trial data and personal recollection. Intersections between these two fields were discussed. ResultsThe understanding of genetic mutations in disease—both in which cells they occur and the timing of mutation development—has expanded in tandem for the fields of ophthalmic oncology and histiocytosis. Similarly, advancements in diagnostic and treatment technology in one field can help patients in the other. For example, in one study, cell-free DNA testing reliably detected mutations in 14 of 18 (78%) patients with suspected histiocytosis. This technique has also been used in ophthalmic oncology as an alternative to invasive biopsy to avoid the risk of tumor externalization, vision impairment, and other side effects. These and other advancements, have allowed both fields to utilize targeted agents to successfully treat diseases with an actionable mutation; or deliver more targeted chemotherapy via the intraarterial technique. ConclusionsThe explosion of molecular genetics technology and targeted therapies has revolutionized cancer treatment, including histiocytosis and ophthalmic oncology. Recent progress in both fields has shown how these seemingly disparate areas have many intersections, and this speaks to the collaborative spirit that is inherent in clinical research.

Internet-Based Abnormal Chromosomal Diagnosis During Pregnancy Using a Noninvasive Innovative Approach to Detecting Chromosomal Abnormalities in the Fetus: Scoping Review.

Chromosomal abnormalities are genetic disorders caused by chromosome errors, leading to developmental delays, birth defects, and miscarriages. Currently, invasive procedures such as amniocentesis or chorionic villus sampling are mostly used, which carry a risk of miscarriage. This has led to the need for a noninvasive and innovative approach to detect and prevent chromosomal abnormalities during pregnancy. This review aims to describe and appraise the potential of internet-based abnormal chromosomal preventive measures as a noninvasive approach to detecting and preventing chromosomal abnormalities during pregnancy. A thorough review of existing literature and research on chromosomal abnormalities and noninvasive approaches to prenatal diagnosis and therapy was conducted. Electronic databases such as PubMed, Google Scholar, ScienceDirect, CENTRAL, CINAHL, Embase, OVID MEDLINE, OVID PsycINFO, Scopus, ACM, and IEEE Xplore were searched for relevant studies and articles published in the last 5 years. The keywords used included chromosomal abnormalities, prenatal diagnosis, noninvasive, and internet-based, and diagnosis. The review of literature revealed that internet-based abnormal chromosomal diagnosis is a potential noninvasive approach to detecting and preventing chromosomal abnormalities during pregnancy. This innovative approach involves the use of advanced technology, including high-resolution ultrasound, cell-free DNA testing, and bioinformatics, to analyze fetal DNA from maternal blood samples. It allows early detection of chromosomal abnormalities, enabling timely interventions and treatment to prevent adverse outcomes. Furthermore, with the advancement of technology, internet-based abnormal chromosomal diagnosis has emerged as a safe alternative with benefits including its cost-effectiveness, increased accessibility and convenience, potential for earlier detection and intervention, and ethical considerations. Internet-based abnormal chromosomal diagnosis has the potential to revolutionize prenatal care by offering a safe and noninvasive alternative to invasive procedures. It has the potential to improve the detection of chromosomal abnormalities, leading to better pregnancy outcomes and reduced risk of miscarriage. Further research and development in this field is needed to make this approach more accessible and affordable for pregnant women.

Impact of Donor-Derived Cell-Free DNA Testing on Patient and Graft Outcomes

Impact of Donor-Derived Cell-Free DNA Testing on Patient and Graft Outcomes

NTRK Fusion as an Acquired Mechanism of Resistance to Selpercatinib in RET Positive Thyroid Cancer

Background: Rearrangement during Transfection (RET) proto-oncogene is involved in the pathogenesis of various thyroid cancer subtypes and drugs that block the RET tyrosine kinase pathways are used in the management of locally advanced and metastatic Medullary Thyroid Cancer (MTC). Acquired resistance to RET inhibitors likely occurs via two different mechanisms: (1) On-target mutations that prevent drug binding and (2) Activated alternative mechanisms which bypass the targeted kinase. We present a unique mechanism of selpercatinib resistance via secondary NTRK fusion mutation in a case of RET altered medullary thyroid cancer. Case Presentation: The patient is a 72-year-old female with stage III metastatic MTC who developed recurrence with newly found RET mutation 7 years after complete surgical resection. Despite initial stable response with selpercatinib for 2 years she rapidly progressed with widespread disease. Cell-free DNA (cfDNA) testing done at the time of progression revealed an NTRK1 fusion. Unfortunately, the patient succumbed to the disease despite starting targeted therapy with larotrectinib. Conclusion: This case highlights the importance of further investigation into mechanisms of resistance to RET inhibitors and drug studies directed towards overcoming them