What do my Signatera ctDNA test results mean for my cancer?

Need help to understand this test results Signatera is a personalized, tumor-informed test for the longitudinal detection of circulating tumor DNA (ctDNA). Interval testing is recommended for all patients. Studies have demonstrated that when ctDNA is detected (Signatera Positive) following surgery or definitive treatment, the risk for disease relapse is high without further treatment. Conversely, when ctDNA is not detected, the patient may be considered at lower risk for relapse. For those with multiple timepoints, upward trending ctDNA levels are suggestive of increasing tumor burden (1,2). For a single time point in isolation, the absolute MTM/mL value has no known clinical significance and should not be compared across patients. Test results should be interpreted in context of other clinicopathological features. ctDNA detection sensitivity may be limited due to blood collection within two weeks of surgery and while the patient is on therapy. 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). Results obtained are specific to the assessed time point. A negative test result does not definitively indicate the absence of cancer. This test is not designed to detect or report germline variation, nor does it infer hereditary cancer risk for the patient. Each Signatera assay is designed to a single tumor for a given patient. At this time, multiple personalized Signatera assays cannot be developed for the same patient. This test is designed to detect ctDNA from the assayed tumor only; new primary tumors will not be detected. There is a low risk that a new primary may share a variant that could interfere with the Signatera test. Testing cannot be performed in patients who are pregnant, have a history of bone marrow transplant, or history of blood transfusion within three months. This test is expected to have limited sensitivity in cancer types such as GIST, renal cell carcinomas, primary brain tumors, and lymphoma due to limited ctDNA shed. 1 Bratman SV, Yang SYC, Iafolla MAJ, et al. Personalized circulating tumor DNA analysis as a predictive biomarker in solid tumor patients treated wi