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Method & Technology: cfDNA Methylation and Machine Learning

The science behind Galleri®: reading methylation signatures on cell-free DNA by next-generation sequencing and converting them into a cancer signal score with a machine-learning classifier.

Clinical Evidence: CCGA, PATHFINDER and NHS-Galleri

Galleri® performance metrics (CCGA3), the designs and results of PATHFINDER 1-2 and the NHS-Galleri randomized trial; an overview of the evidence program with more than 385,000 participants.

Patient Selection and Clinical Use

Who is and is not eligible; the prescribing process, blood draw, and planning the diagnostic work-up after the result.

Limitations and Result Interpretation

False positive/negative probabilities, stage I sensitivity, non-use in symptomatic patients, and the pathway to follow when a signal is detected.

CTC and Microfluidic Technology

The biology of circulating tumor cells (CTCs), the patented microfluidic capture principle, and the analysis workflow from a single blood tube.

Characterization Panels: Identification, ER/PR/Her2, PD-L1

Composition and reading of the three panels: CTC identification with CD45⁻/cytokeratin⁺/DAPI⁺, ER/PR/Her2 for breast cancer follow-up, and PD-L1 for immunotherapy response.

Clinical Monitoring and RUO Boundaries

Monitoring disease course and treatment response through serial measurements; the panels are research-use-only (RUO) and cannot guide diagnosis or treatment.

ELSA-seq and Methylation-Based Detection

The single-strand-library ELSA-seq platform, screening of more than 70,000 methylation regions, and the scoring logic of the BRMERMAID® algorithm.

The THUNDER Study: Design and Results

Design and performance results of the prospective, independent, blinded validation study NCT04820868 (69.1% / 98.9% / 83.2%), with the full reference list.

Eligibility and Contraindications

The 50–75 age range, risk factors and the recommended user profile; absolute exclusion criteria (transplantation, immunosuppression, cancer treatment within 3 years, and more).

Result Interpretation and Safety Notices

The cancer signal score threshold (0.5), interpreting 'detected / not detected', tissue-of-origin prediction, and the safety notices emphasizing the test is not diagnostic.

Liquid Biopsy: a Non-Invasive Alternative to Solid Biopsy

Analysis of CTCs, ctDNA and exosomes from blood; a components table, advantages, and a CTC-vs-ctDNA selection guide.

What Is a CTC (Circulating Tumor Cell)?

The rare cells that carry metastasis: clinical importance, detection challenges, and the flow cytometry identification approach.

Solid Biopsy vs Liquid Biopsy: a Comparison

A comparison table across invasiveness, repeatability, heterogeneity and cost; when to use which?

CTC Counting by Flow Cytometry

The standard CTC panel (CD45, CK, EpCAM, DAPI), rules of rare-event analysis, and the gating strategy.

ctDNA: What Is Circulating Tumor DNA?

The cfDNA-ctDNA distinction, measurement indications (mutations, MRD, resistance) and analytical challenges.

Minimal Residual Disease (MRD) and Liquid Biopsy

Definition and prognostic importance of MRD; CTC- and ctDNA-based MRD approaches, and the research scope.

CTC Characterization: Beyond Counting

CTC phenotyping with PD-L1, HER2, ER/PR, EMT markers and Ki-67; the multicolor flow cytometry approach.

Sample Preparation Guide for CTC Analysis

Tube choice, blood draw protocol, transport conditions and common mistakes; the pre-analytical layer that determines result quality.

EMT (Epithelial-Mesenchymal Transition) in CTCs and the Metastasis Mechanism

The molecular program of EMT, the hybrid E/M phenotype, CTC clusters, the immune-escape intersection and EMT measurement platforms; a comprehensive technical guide.

ctDNA-Based Minimal Residual Disease (MRD) Test Protocol

Tumor-informed and tumor-naive MRD strategies, UMI/duplex error mathematics, CHIP management, timing and validation; an implementation guide with appendices.

Measuring Tumor Mutational Burden (TMB) by Liquid Biopsy

bTMB vs tTMB, the calculation method, ctDNA fraction and reliability, Poisson statistics, panel design and threshold interpretation.

Liquid Biopsy Endpoint Design in Clinical Trials

Endpoint types, the time-point matrix, sample logistics, statistical power, regulatory perspective and central laboratory selection; with checklists and cases.