Tissue v. cfDNA
Although liquid biopsy (blood) profiling to detect and characterize cancer from fragments of circulating tumor DNA continues to emerge as a clinically useful tool (PLoS1, NILE2, etc.), solid tissue profiling remains the gold standard and produces the most reliable results.
Concordance details of non-small-cell-lung-cancer (NSCLC) tissue biopsies performed by Caris over the last year vs. blood based cell-free (cfDNA) results as reported from multiple publication sources at the intent to treat level are outlined in the below diagram.
- Solid tumor testing by Caris is reported at 92% for the intent to treat population, 84% for complete results and 16% for partial results returned (meaning not enough tissue to perform all assays ordered), which still contain actionable information.
- Additional detail is provided for key actionable biomarkers such as ALK, ROS1, EGFR, BRAF and PD-L1 – all results are higher and more reliable than blood only profiling.
- In the intent to treat population, cfDNA liquid biopsy success rate was 57%
- Additional detail is provided for key biomarkers such as ALK, ROS1, EGFR, BRAF and PD-L1 – all results are lower and less reliable than solid tumor profiling and PD-L1 is not in tested for by blood.
Caris tissue testing returns successful results in 92% of patients in an average of 10 days. The data presented demonstrated that testing by cfDNA returns results on 57% of patients in an advertised 9 days.2
- Tissue testing remains the gold standard.
- cfDNA can be a viable clinical tool in cases where tissue is not available or limited.
- This data is consistent with numerous publications where researchers have concluded that cfDNA analysis is “not a replacement for histologic confirmation and immunohistochemistry from a diagnostic biopsy” but rather the “data thus supports a complementary role for plasma cfDNA NGS.”6