My ctDNA is rising but my scans are clear. What does that mean?

Why blood sees it before imaging does

A CT or PET scan needs a lesion large enough to resolve. Tumor DNA shed into blood can be measured well below that threshold, which is why a rising ctDNA trend in a patient with a clean scan is a recognized and increasingly common situation rather than a contradiction.

The trend is the signal. One detectable value can reflect many things. Values climbing across serial draws, especially on a tumor-informed assay such as Signatera or a panel such as Guardant Reveal, points more firmly at growing disease burden.

What usually happens next

Common responses include shortening the interval between blood draws, repeating imaging sooner than scheduled, adding a different imaging modality that may be more sensitive for your disease, or in some settings changing systemic therapy on the molecular signal alone.

The choice depends on whether an effective option exists that would be used now rather than later, and whether evidence in your specific cancer supports acting on the blood result before imaging confirms it.

• Confirm the trend with a repeat draw on the same assay
• Ask whether a different scan type would see disease your current imaging misses
• Re-read the full molecular profile for options that were not relevant at diagnosis
• Ask whether any trial accepts molecular-only recurrence for entry

Where an independent read helps

This is one of the most common reasons people contact MITOTICS®. The record contains a genomic panel from months or years earlier, a series of ctDNA values, and imaging that has not changed. Reading those together, in order, against current treatment options is exactly what a Molecular Strategy engagement does.

Related questions

Is rising ctDNA always recurrence?

Not always. Assay variation, clonal hematopoiesis on some tumor-agnostic panels, and other biological factors can contribute. A tumor-informed assay with a consistently rising trend is harder to explain any other way.

How soon do scans usually catch up?

It varies by cancer type and tumor biology, and published lead times commonly range from a few months to over a year. That window is why the result is useful in the first place.

Should I ask to change treatment now?

Ask the question directly, and ask what evidence supports acting now in your specific disease. In some cancers the case is strong, in others closer monitoring is the reasonable answer.