The Galleri test and NHS screening, and how they fit together

We are a private clinic, and we offer the Galleri test, so treat what follows as our best attempt at a fair comparison rather than a neutral one. With that said, the relationship between a private multi-cancer test and NHS screening is genuinely worth understanding, because the two do different jobs and the sensible move is usually to use them together rather than to choose between them.

The NHS runs national screening programmes for three cancers: breast, bowel and cervical. It also offers a targeted lung scan to people at high risk, and it is expanding. These programmes are free where you are eligible, they are backed by decades of evidence, and they are proven to save lives. If you are invited for a mammogram, sent a bowel-screening kit, due a smear or offered a lung scan, the single most valuable thing you can do for your cancer risk is to take up the offer. Nothing a private clinic sells changes that.

What the NHS programmes do not do is look across the many cancers that have no screening programme at all, which is most of them. That is the gap a multi-cancer test like Galleri is designed to look into. From one blood sample it screens for a signal shared by more than fifty cancer types, and predicts where a signal is coming from so that follow-up can be focused. It is a wide, shallow look, where the NHS programmes are narrow and deep. The two are complementary by design.

They are also different in what they promise. The NHS programmes are chosen precisely because the evidence that they save lives is strong. A multi-cancer blood test is newer, and the picture is mixed: the largest trial did not meet its main target of cutting late-stage cancers over three years, and the evidence that it helps people live longer is not yet in. It detects cancer signals well, with few false alarms, sometimes early. Whether that changes outcomes is still being studied. So it is reasonable to add it as an extra layer, and unreasonable to treat it as a replacement for the screening that is proven.

The practical version is simple. Keep every NHS screening appointment you are offered. See a doctor about any symptom rather than waiting for a test to catch it. And if, on top of that, you want a wider look across the cancers the programmes do not cover, a multi-cancer test is a considered option worth discussing. A clear result from it is reassuring but not a guarantee, so it changes nothing about keeping up with the free programmes.

If you would like to work out how a multi-cancer test fits with the screening you are already entitled to, that is a good conversation to have with a doctor who will tell you about both.