Abstract P2-09-01: Preliminary Findings from the Breast Cancer Combined Visualization And Characterization Tools (bCOMBAT): Low-Dose PEM and Liquid Biopsy Study
Bibliographic record
Abstract
Abstract Purpose: This study evaluates the effectiveness of low-dose Positron Emission Mammography (PEM) and liquid biopsy in detecting and characterizing breast abnormalities in high-risk patients. Materials and Methods: Approved by the research ethics board, this prospective study involves high-risk women from the Ontario Breast Screening Program (OBSP) at the University Health Network (UHN). Participants scheduled for MRI-guided biopsy of suspicious lesions detected by standard MRI are subjected to low-dose PEM using 74 MBq of fluorine 18-labeled fluorodeoxyglucose (18F-FDG) and liquid biopsy for plasma analysis. Preliminary Findings: Among the first high-risk 24 patients analyzed (median age 41; range 33–66) from a planned cohort of 100, four had biopsy-confirmed cancer, including two cases of ductal carcinoma in-situ (DCIS) and two of invasive cancer. Of these, low-dose PEM imaging identified three malignancies and missed one DCIS, with no false positives reported. Liquid biopsy, measuring tumor content and performing fragmentomic analysis on cell-free DNA, did not detect any cancers. Further analysis using cell-free methylated DNA immunoprecipitation and high throughput sequencing (cfMeDIP) is pending. Conclusion: Early results indicate that low-dose PEM is more sensitive than liquid biopsy for detecting breast cancer in high-risk populations and maintains high specificity relative to MRI. Citation Format: Vivianne Freitas, Oleksandr Bubon, Samira Taeb, Frederick Au, Supriya Kulkarni, Sandeep Ghai, Shayna Parker, Michael Waterston, Alla Reznik. Preliminary Findings from the Breast Cancer Combined Visualization And Characterization Tools (bCOMBAT): Low-Dose PEM and Liquid Biopsy Study [abstract]. In: Proceedings of the San Antonio Breast Cancer Symposium 2024; 2024 Dec 10-13; San Antonio, TX. Philadelphia (PA): AACR; Clin Cancer Res 2025;31(12 Suppl):Abstract nr P2-09-01.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.003 | 0.003 |
| Meta-epidemiology (narrow) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.001 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.001 | 0.001 |
| Research integrity | 0.001 | 0.001 |
| Insufficient payload (model declined to judge) | 0.004 | 0.001 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".