Summary of mutations identified in 69 plasma samples of ovarian cancer patients. Samples were analyzed by TAm-Seq and in parallel by digital PCR. Using parameters optimized for plasma DNA, false-positive calls were lost, whereas all confirmed calls were retained, resulting in specificity and PPV of 100%.
First set of plasma samples | |
Plasma samples analyzed | 7 |
Point mutations originally detected by digital PCR, using patient-specific assays targeting mutations identified in tumor samples | 7 |
Point mutations identified directly in plasma by TAm-Seq | 8 |
De novo mutations identified by TAm-Seq only, subsequently confirmed by digital PCR | 1 |
Second set of plasma samples | |
Plasma samples analyzed | 62 |
Point mutations detected by digital PCR at AF >2% | 40 |
Point mutations with AF >2% (by digital PCR) identified by TAm-Seq | 39 |
Point mutations missed by TAm-Seq due to sampling error | 1 |
Sensitivity of TAm-Seq for identifying mutations at AF >2% | 97.5% |
PPV of mutations called by TAm-Seq with AF >2% | 97.5%* |
ctDNA in ovarian cancer | |
Advanced ovarian cancer patients in both sets† | 38 |
Patients where TAm-Seq identified cancer mutations | 20 |
*One unconfirmed substitution was called at AF >2% using parameters optimized for FFPE material.
†The first set included 7 patients (Table 1), and the second set included 37 patients (table S6), 6 of whom overlap.