Abstract 5596: Cell free DNA levels and fragmentation patterns in different liquid biopsy analytes (blood, urine and vaginal fluid) in cervical cancer patients
Notice bibliographique
Résumé
Abstract Background: Cervical cancer (CC) is the 4th most commonly diagnosed cancer among women, with approximately 528,000 new cases annually. Current screening approaches for this disease have certain limitations; Pap tests require dedicated cytopathology infrastructure, while human papillomavirus (HPV) DNA testing may lead to invasive procedures in patients with transient infection. Liquid biopsy has emerged as a minimally invasive approach to detect and monitor disease progression and treatment response. We and others have previously demonstrated the clinical utility of circulating tumor (ct)DNA to monitor HPV+ cancers. Moreover, cell free (cf)DNA fragmentation patterns have been found to be a biomarker of disease burden. This cfDNA is thought to originate largely as a result of cell death, where small fragments of ~167 bp are associated with apoptosis and larger fragments (>1000 bp) are associated with necrosis. Despite advances in liquid biopsy techniques, little is known about the composition of cfDNA from different analytes in CC patients. Methods: The aim of this study was to compare the presence and composition of cfDNA from different liquid biopsy analytes in patients with CC and high grade cervical intraepithelial neoplasia or dysplasia (CIN/CD). Blood, urine, and vaginal swabs were collected from 20 patients with CC and 9 patients with CIN/CD at the McGill University Health Centre. All samples were centrifuged twice to isolate supernatant. Samples were tested for HPV ctDNA by ddPCR. Analysis of fragment length was performed using the Agilent Bioanalyzer 2100. Dominant fragment was determined as the DNA fragment with the highest concentration, while overall fragment was calculated as the average fragment across all bioanalyzer peaks. Results: HPV16/18 ctDNA was detectable 14/20 CC patients and 2/6 CIN patients, and 0/3 CD patients in plasma, urine, and vaginal swab. Concordance for all sample types tested was seen in 90% of cases. On average, fragment analysis demonstrated 174, 195, and 183 bp dominant small fragments in plasma, urine and vaginal swab, respectively. Plasma samples showed only smaller fragments (range: 168-187 bp). Other analytes displayed a predominance of larger cfDNA, with an overall fragment size of 3996 and 5194 bp in urine and vaginal swab, respectively. Conclusions: HPV-DNA was detectable in all analytes sampled in patients with CC and CIN, with a trend of higher detection in CC samples. The fragmentation patterns of cfDNA varied between patients and within patients across analytes, with larger fragments - likely of necrotic origin - seen only in urine and vaginal swab cfDNA. Smaller fragments - likely related to apoptosis - were seen across all sample types studied. Overall, analysis of fragmentation may provide valuable insight into cfDNA origins in different sample types and provide a novel biomarker for diagnosis and surveillance. Citation Format: Sarah Tadhg Ferrier, Erica Mandato, Alexandra Bartolomucci, Thupten Tsering, Shuk On Annie Leung, Julia Valdemarin Burnier. Cell free DNA levels and fragmentation patterns in different liquid biopsy analytes (blood, urine and vaginal fluid) in cervical cancer patients. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 5596.
Récupéré en direct depuis OpenAlex et désinversé. Les résumés ne sont pas conservés dans cette base de données : les index inversés représentent 8,6 Go des 9,3 Go de texte de la base, et le serveur dispose de 13 Go libres.
Comment cette classification a été obtenuedéplier
Prédiction machine sur la base complète
Imitation des enseignantsNi prévalence calibrée, ni vérité terrain. Validation humaine à venir. Le volet Gemma est une étiquette directe du modèle pour chaque travail de la base, lue sur la notice réduite au titre. Le volet Codex est un classifieur appris des 10 348 étiquettes directes de Codex et calibré sur les taux pondérés de l'échantillon; les champs sans appui suffisant ne portent aucun appel Codex. Le mode candidate est l'union des deux volets; le consensus est leur intersection. Ces sorties portent le statut machine_predicted_unvalidated et ne sont pas des étiquettes humaines.
Scores du classifieur distillé par catégorie (deux têtes)
| Catégorie | Codex | Gemma |
|---|---|---|
| Métarecherche | 0,000 | 0,001 |
| Méta-épidémiologie (sens strict) | 0,000 | 0,000 |
| Méta-épidémiologie (sens large) | 0,000 | 0,000 |
| Bibliométrie | 0,001 | 0,001 |
| Études des sciences et des technologies | 0,000 | 0,000 |
| Communication savante | 0,001 | 0,000 |
| Science ouverte | 0,000 | 0,000 |
| Intégrité de la recherche | 0,000 | 0,000 |
| Charge utile insuffisante (le modèle a refusé de juger) | 0,002 | 0,000 |
Scores machine (provisoires)
Les deux têtes enseignantes du modèle étudiant, lues sur ce travail. Un score ordonne la base pour la relecture; il n'affirme jamais une catégorie, et le statut de validation accompagne chaque rangée tel quel.
Scores de référence d'un modèle non mature (critères de maturité non atteints, 7 itérations). Un score ordonne; il n'affirme jamais une catégorie.
score_only:v0-immature-baseline · tel quel depuis la passe de notation : score_only signifie que le nombre peut ordonner les travaux, et qu'aucune étiquette de catégorie n'en découleClassification
machine, non validéePrédiction automatique; un appel candidat d’une seule source (Gemma direct ou Codex distillé), pas un consensus.
Le détail, modèle par modèle et score par score, se trouve en fin de page sous « Comment cette classification a été obtenue ».