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Tim McDonald's avatar

I realized I used to terms that may not be familiar to many.

ctDNA (circulating tumor DNA) — Tiny fragments of DNA that cancer cells shed into the bloodstream. A blood test can detect them even when scans show nothing, which is why someone can have clear scans and a positive ctDNA result at the same time.

MRD (measurable residual disease) — The small amount of cancer that may remain after treatment, too little to show up on scans but detectable through sensitive tests like ctDNA.

"MRD-positive" means there's measurable evidence cancer may still be present at a molecular level. (You'll also see it written as "minimal residual disease" — the older name for the same thing.)

MRD trial — A clinical research study testing how best to monitor or treat patients who are MRD-positive — often people exactly in the "clear scans, positive ctDNA" situation.

Surveillance — The phase after treatment ends, when you're monitored regularly through scans and bloodwork to catch any return of cancer early. Not the same as being in active treatment.

Remission — When the signs and symptoms of cancer are reduced or gone. It doesn't always mean cured — which is where MRD testing comes in.

Survivorship program — A dedicated clinical program focused on life after cancer treatment: long-term side effects, monitoring, mental health, and quality of life — not just watching for recurrence.

Molecular level — Detecting cancer by its DNA or biological markers rather than by seeing a tumor on a scan. Molecular evidence can appear months before anything shows up on imaging.

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