Cell-free Tumor DNA (cfDNA) Quantitative Analysis Using Fluorescence In Situ Hybridization (FISH) Probe

What Does This Test Measure?

The test analyzes tiny pieces of DNA (called cell-free DNA or cfDNA) found in your blood. These fragments come from both healthy and cancerous cells. The FISH probe targets specific genetic regions to detect abnormalities, such as gene amplifications or deletions, that may indicate cancer.

Why Might This Test Be Ordered?

Your healthcare provider may recommend this test if you have a known cancer diagnosis or are at high risk for certain cancers. It can also be used to monitor treatment effectiveness or check for recurrence by looking for persistent genetic changes in your blood.

Sample Collection and Preparation

A blood sample is drawn from a vein in your arm. The blood is processed to isolate cell-free DNA, which is then tested using the FISH probe method. This process helps identify specific genetic markers without needing a biopsy.

What Does a Positive or Negative Result Mean?

A positive result may show genetic changes linked to cancer, but it doesn’t confirm cancer alone. Results are interpreted alongside clinical findings, imaging, and other tests. A negative result means no detectable genetic changes were found in this sample, but further testing may still be needed.