Multi-cancer detection: what it can (and can't) do.

A multi-cancer early detection (MCED) test is a blood test that looks for signals shed by tumours (such as circulating tumour DNA) to detect cancers that often have no routine screening. It is a promising complement to standard screening, not a replacement, and not a diagnosis.

Why MCED is of interest

Most cancers have no population screening program. MCED tests aim to detect a signal common to many cancers from a single blood draw, and can suggest the likely tissue of origin to guide follow-up.

What the evidence shows: honestly

• PATHFINDER (Schrag et al. The Lancet 2023): demonstrated MCED testing is feasible in practice and can detect cancers, while highlighting false positives and the need for careful follow-up.
• Developing evidence: large randomised trials assessing whether MCED reduces cancer mortality are ongoing; results are not yet available.
• Complement, not replacement: a negative MCED result does not rule out cancer, and it does not replace bowel, breast, cervical, prostate or skin screening.

Evidence-based reference ranges

An MCED test returns a qualitative result, not a numeric range:

Clinical interpretation

• A "signal detected" result is not a cancer diagnosis. It prompts targeted investigation to confirm or exclude cancer.
• A "no signal detected" result is reassuring but cannot rule out cancer; routine screening must continue.
• MCED is best used as an informed choice, with clear counselling about benefits, limitations and the possibility of false positives.

How this works at HodieLabs

MCED testing is offered as an add-on to any HodieLabs membership, with doctor counselling before and after, and any positive signal managed through a clear diagnostic pathway at our Melbourne Preventative Health & Longevity Clinic.

References

1. Schrag D, et al. (PATHFINDER). A prospective study of a multicancer early detection blood test. Lancet. 2023;402:1251–1260.
2. Klein EA, et al. Clinical validation of a targeted methylation-based multi-cancer early detection test. Ann Oncol. 2021;32:1167–1177.
3. Large randomised trials of MCED and cancer mortality are ongoing.

This page is general information from the HodieLabs Evidence-Based Clinical Library, not medical advice. Speak with your GP about what testing and care is appropriate for you.