A New Blood Test Found A Surprising Signal In Early-Stage Cancer

Stomach cancer can be tricky to catch early because its symptoms, like bloating and indigestion, can look a lot like everyday digestive issues.

Doctors often use an endoscopy, which involves passing a thin camera down the throat to examine the stomach. But researchers are exploring another option that could make detection less invasive.

In a new study1, scientists investigated whether a small blood sample could reveal clues to stomach cancer, even in its earliest stages.

About the study

Researchers collected blood samples from 865 people. Of these, 434 had untreated stomach cancer, while 431 had noncancerous stomach conditions. They wanted to find out whether DNA traces inside red blood cells could help tell the two groups apart.

Red blood cells don't have a nucleus, where most of our DNA is stored.

However, they can retain tiny amounts of DNA. Researchers analyzed these traces to identify patterns associated with stomach cancer, then used those patterns to develop a blood-based detection method.

They evaluated how well this method worked across several independent groups, including people with early-stage cancer.

The blood-based method detected up to 89% of early-stage cases

Across the groups tested, the method correctly identified 83% to 90% of people who had stomach cancer. For early-stage cases, it detected 82% to 89%, a promising result for a disease that can be difficult to identify before it progresses.

It also distinguished cancer from noncancerous stomach conditions and identified around 80% of cancer cases missed by standard tumor marker blood tests.

Existing blood-based markers often miss stomach cancer, which limits their use for early detection.

The results suggest that DNA traces in red blood cells could provide useful clues that current blood tests miss. However, these detection rates don't establish how well the method would work as a screening tool in the general population.

Why endoscopy is still essential

This blood-based method is still experimental, and larger studies are needed to determine how reliably it works in real-world screening.

For now, endoscopy remains the standard way to investigate suspected stomach cancer. It allows doctors to examine the stomach lining directly and collect tissue samples for testing if they find anything unusual.

The experimental blood method could eventually help identify people who need further evaluation, but it can't replace that direct examination or confirm a diagnosis on its own.

What you can do right now

While researchers continue investigating this approach, there are practical steps you can take to protect your digestive health:

The takeaway

Red blood cells may hold clues that help doctors spot stomach cancer earlier, with this experimental method detecting up to 89% of early-stage cases.

There's still a way to go before it reaches clinical practice, so for now, trust your instincts and get persistent symptoms checked.