Cancer doctors have long relied on scans and tissue biopsies to diagnose and track cancer. While these tools are important, they can be invasive, expensive, and may not always show how cancer is changing in real time. New research suggests that biomarkers that are proteins and RNA found in the blood could offer a simpler way to detect cancer earlier and monitor it over time.
A recent study explored whether specific blood-based markers—SOX2, PIWI proteins, and MALAT1—could help identify cancer and provide useful information about how aggressive a tumor may be.
Why Scientists Are Looking at Blood Proteins for Cancer Care
Cancer cells release molecules into the bloodstream as they grow, divide, and die. These molecules can include proteins and RNA that reflect what is happening inside the tumor. Because blood tests are less invasive than biopsies, researchers are working to find reliable blood markers that could help with:
- Early cancer detection
- Tracking cancer growth or spread
- Monitoring response to treatment
The goal is to create tests that are easier for patients and give doctors faster, clearer information.
Key Proteins and RNA Studied for Cancer Detection
This study focused on three markers found in blood plasma:
- SOX2 – A protein involved in cell growth and stem-cell behavior. It is often higher in aggressive cancers and linked to faster tumor growth.
- PIWI proteins – A group of proteins that help control genetic stability. In cancer, they are linked to increased cell division and tumor aggressiveness.
- MALAT1 – A long non-coding RNA linked to cancer spread and resistance to treatment. High levels are often seen in cancers that invade nearby tissues.
These markers were chosen because earlier research suggested they play important roles in cancer progression.
How the Study Was Conducted
Researchers studied 300 people in total:
- 150 patients with cancer, including colorectal, breast, and prostate cancer
- 150 healthy individuals matched by age and sex
Blood samples were collected before any cancer treatment began. The researchers measured:
- RNA levels using qRT-PCR
- Protein levels using ELISA tests
They also compared blood results with tumor tissue markers already used in cancer care, such as Ki-67 (a marker of fast-growing tumors) and markers linked to cancer spread.
What the Results Showed
The study found clear differences between people with cancer and healthy controls:
- SOX2, PIWI proteins, and MALAT1 were all significantly higher in cancer patients
- These markers were elevated across all three cancer types
- Higher levels were linked to markers of fast tumor growth and aggressiveness
The tests performed well in identifying cancer:
- Each marker showed good accuracy on its own
- Combining markers improved accuracy even further
- Some combined tests reached over 90% accuracy in distinguishing cancer from non-cancer cases
Importantly, the blood markers also matched what doctors saw in tumor tissue, suggesting they reflect real tumor behavior.
How Blood Proteins Can Help Monitor Cancer Over Time
Because these markers can be measured repeatedly through blood tests, they may help doctors:
- Track whether cancer is growing or responding to treatment
- Spot early signs of treatment resistance
- Monitor aggressive cancers more closely
This approach could reduce the need for repeated biopsies and provide quicker feedback during treatment.
What This Research Means for the Future
This study supports the idea that blood-based protein and RNA markers could become valuable tools in cancer care. While more studies are needed—especially long-term and multi-center trials—the findings suggest these markers may help improve early detection and ongoing monitoring.
For now, these tests are still research tools, not routine clinical tests. But they represent a promising step toward simpler, less invasive cancer diagnostics.
Source:
Kldiashvili E, Abiatari I, Kekelia E, et al. SOX2, PIWI proteins, and MALAT1—plasma-based emerging biomarkers for cancer detection and monitoring. PLoS One. 2025;20(7):e0328557. doi:10.1371/journal.pone.0328557. Accessed by: https://pubmed.ncbi.nlm.nih.gov/40674376/
