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Signatera CT DNA Test: What numbers have you seen on your tests?
Pancreatic Cancer | Last Active: Jan 7 11:08am | Replies (11)Comment receiving replies
They scale the graph's vertical axis to accommodate your highest reading.
When my highest reading was 0.14, the graph had a range of 0 to approximately 0.15; after I got a higher reading (0.61), the graph had a range of 0 to 0.65
All my non-zero readings (range 0.04 to 0.61) have the triangle marker (as opposed to solid, filled-in circle) on the graph, indicating "Positive below analytical range" according to the footnote under the graph.
Later footnotes include the following text:
Interpretation and Limitations
Signatera is a quantitative test and reports in units of mean tumor molecules per ml (MTM/mL), which is comprised of three measured components (plasma volume, cell free DNA (cfDNA) concentration, and Variant Allele Frequency (VAF)).
The MTM/mL number will be qualified if any measured component falls outside the analytical measurement range for that component. The analytical sensitivity is 95% at the limit of detection (0.3 MTM/mL).
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FWIW, my CA19-9 was 126 last week.
My last Signatera result (5 weeks ago) finally came down to 0.0 again (negative), but CA19-9 from the same blood draw was 265.
My highest Signatera result (5 months ago) was 0.61, and CA19-9 from the same blood draw was 2315.
We've been doing the Signatera test every 8-10 weeks for about 2.5 years, along with biweekly CA19-9. It's pretty evident Signatera does not provide much insight (or positive detection) when CA19-9 is relatively low (under 200-300). CA19-9 has provided much more granularity for me at low levels than Signatera.