Blood as liquid Biopsy:
- Minimally-invasive
- Repeatable
- Representative of cancer heterogeneity
- Versatile
- Informative
Importance of upstream workflow to generate quality sample.
CTC and CTC clusters:
Reflective of metastatic
tumor
Source of biomarkers
(suitable for multiomics
analysis)
Rare event: 1 CTC / 109
blood cells
Intended use
“The Parsortix® PC1 system is an in vitro diagnostic device intended to enrich circulating tumor cells (CTCs) from peripheral blood collected in K2EDTA tubes from patients diagnosed with metastatic breast cancer. The system employs a microfluidic chamber (a Parsortix cell separation cassette) to capture cells of a certain size and deformability from the population of cells present in blood. The cells retained in the cassette are harvested by the Parsortix PC1 system for use in subsequent downstream assays.
The end user is responsible for the validation of any downstream assay. The standalone device, as indicated, does not identify, enumerate or characterize CTCs and cannot be used to make any diagnostic/prognostic claims for CTCs, including monitoring indications or as an aid in any disease management and/or treatment decisions.
Platform technology
The Parsortix system harvests cancer cells from blood based on their larger size and lack of deformability
Other cells can be captured:
- white blood cells associated with the tumor microenvironment
- megakaryocytes (frequency may relate to cancer)
- fetal cells from maternal blood
Proof Of Concept work:
No CTC loss following plasma removal, prior to Parsortix enrichment.
Can we allow for dual detection of targets/variants which may have an impact on patient care?
ctDNA and Parsortix-derived CTC-DNA can be analysed from single blood sample across multiple cancer types to detect mutations using Illumina Cell-Free DNA prep with enrichment combined with custom panel targeting Lung Cancer.
Illumina Cell-Free DNA prep with Enrichment and custom 79 gene panel enables a flexibility in the targeted genes.
Contrived samples were used to assess the analytical performance of the assay:
Two cell lines with known mutations, were spiked into Parsortix-enriched samples.
DNA samples from CTC were extracted and processed following Illumina Cell-Free DNA prep with Enrichment procedure.
Table: expected mutations to be detected in spiked samples
2 cohorts of Lung Cancer patient
- 1st cohort: 8 Lung Cancer patient samples (no treatment)
- 2nd cohort: 19 Lung Cancer patient samples (may be under treatment)
Good quality samples
Overall, 93% of samples with at least one oncogenic gene detected.
1st cohort - Lung cancer panel (n=8):
-
CTC (average) = 49 and CTC (median) = 20
- 100% patients showed oncogenic mutations signal for one or more targets.
- 32 genes (74 variants) seem to be specifically detected in this cohort:
Table: expected mutations to be detected in spiked samples
2nd cohort - Lung cancer panel (n=19):
-
CTC (average) = 4 and CTC (median) = 3
- 90% of patients with at least one oncogenic mutations in CTC for one or more targets.
-
38 genes (214 variants) have been specifically detected in this cohort:
Table: expected mutations to be detected in spiked samples
Full cohort - Lung cancer panel (n=27):
43 genes (247 variants) have been specifically detected in this cohort:
Analysing both analytes give access to twice as many mutations, which could be investigated and/or use as “potential” biomarkers.
Validation
of patient data using another cohort of patient samples (under treatment – n=10)
-
Use of a pan-CANCER NGS panel, with blocker displacement amplification
- 20 genes (27 variants) have been specifically detected in this cohort:
Table: expected mutations to be detected in spiked samples
Table: expected mutations to be detected in spiked samples