Pan-Tumor Assay for Solid Tumors
GTC’s Liquid Trace Solid Tumor is a highly sensitive pan-cancer test that evaluates cell-free RNA and DNA (cfRNA and cfDNA), providing highly informative data that can be used for diagnoses, evaluating the host immune response, and identifying biomarkers for predicting responses to various therapies.
Furthermore, Liquid Trace Solid Tumor may provide additional information on changes not detected with tissue biopsies, including germline mutations and mutations in the subclones not present in the tissue sample (heterogeneity).
Examples of types of solid tumors Liquid Trace can detect:
Use CSF as a liquid biopsy specimen for your brain cancer patients
Many conventional liquid biopsy tests are dependent solely on cfDNA analysis, which presents multiple challenges. These include variations in DNA shedding between tumors as well as low sensitivity (especially in early-stage cancer), difficulty in detecting fusion genes (i.e., chromosomal translocations leading to the expression of chimeric mRNA from two genes), and inability to detect the numerous biological processes that modify RNA expression levels, such as alternative splicing, stability, and allele-specific methylation. The latter limitation is critically important as recent studies have shown that RNA testing provides another level of biological information regarding the tumor and its microenvironment.
-TMB evaluation is now part of Liquid Trace Solid Tumor
The Benefits of cfRNA
Studies have found RNA sequencing to be more sensitive for some types of mutations, likely because cancer cells typically contain one copy of mutated DNA but numerous copies of RNA. This research is consistent with GTC’s findings that cfRNA has increased sensitivity over cfDNA alone. More specifically, cfRNA allows GTC’s Liquid Trace to detect mutations and fusions in hematologic and solid tumor samples that may be undetected with conventional cfDNA testing.
T-cell and B-cell Clonality Detection: The detection of T- and B-cell clonality is important because it can help diagnose and monitor certain types of malignancies. When malignant transformation occurs in a T- or B-cell, the cells can undergo uncontrolled clonal expansion, resulting in the accumulation of many cells with the identical T- or B-cell receptor.
HLA Class I Genotyping: Useful when identifying patients who may be candidates for immunotherapy.
Epstein-Barr Virus (EBV): Important for diagnosis and classification of lymphoid neoplasms and some solid tumors.
Human Papillomavirus (HPV): Chronic infection with high-risk HPV subtypes is associated with increased risk of anogenital and oropharyngeal cancer. Detection of HPV mRNA suggests active (productive) infection.
Torque Teno Virus (TTV): This virus was first discovered in a patient with non-A-E hepatitis and is now regarded as a part of the human virome. In general, TTV does not cause pathology in immunocompetent individuals. This virus is considered as a marker of the degree of immune competence in patients with immunological impairment and inflammatory disorders. High TTV load is associated with increased risk of infection. In patients with organ transplant, low TTV load is associated with an increased risk of rejection.
Sensitivity is 0.1 to 0.01 for non-hot spot, 0.01 to 0.001 for hotspot and <0.001 for tumor informed or prior Hx.
For DNA, QNS is rare (<0.1%), but it is higher for RNA (Good DNA results but poor RNA results. Of course, if we receive 3 ml of plasma (6 ml blood), the sample is QNS for performing RNA testing.
VAF (Variant Allele Frequency) value: This value is used to monitor the disease in liquid bx. The high the VAF means higher tumor load. Patients showing reduction in VAF after treatment means they are doing better.