Discover how biomarkers, liquid biopsies, and AI are detecting cancer years before traditional methods
Imagine if we could detect cancer not when symptoms appear, but three years earlier—when treatments are most effective and survival rates are highest. This isn't science fiction; it's the remarkable reality of modern clinical chemistry, a field that has quietly revolutionized how we approach cancer diagnosis. Through simple blood tests and sophisticated analysis of biological molecules, clinical chemists are developing powerful new ways to detect cancer at its earliest, most treatable stages 1 .
Clinical chemistry serves as our molecular detective agency, searching for subtle clues in bodily fluids that signal the presence of cancer long before tumors become detectable through traditional imaging.
These clues—known as biomarkers—include proteins, genetic material, and metabolic products that cancer cells release into the bloodstream. By identifying and measuring these biomarkers with incredible precision, clinical chemistry is transforming cancer from a often-lethal threat to a manageable condition through early intervention 2 3 .
At the heart of clinical chemistry's approach to cancer detection are biological markers, or biomarkers. These are measurable substances whose presence indicates a particular disease state. In cancer, biomarkers can include:
Like PSA (prostate-specific antigen) for prostate cancer
Such as DNA mutations or RNA fragments from tumor cells
That reflect changes in cellular metabolism caused by cancer
That have broken away from tumors and entered circulation
The challenge hasn't been finding these biomarkers—it's been identifying which ones are reliable indicators of specific cancers and developing sensitive enough tests to detect them at extremely low concentrations 2 4 .
Early cancer detection tests typically focused on single biomarkers like PSA. However, researchers soon realized that no single molecule could provide a complete picture of cancer presence, type, and aggressiveness. This understanding led to the development of multiplex testing—simultaneously measuring multiple biomarkers to create a more accurate diagnostic signature 4 .
This approach mirrors how detectives use multiple pieces of evidence rather than relying on a single clue. For prostate cancer, tests like the 4Kscore now measure four different kallikrein proteins plus clinical factors to better predict cancer risk 4 .
Perhaps the most significant advancement in cancer detection has been the development of liquid biopsies—tests that detect cancer biomarkers in blood rather than requiring tissue samples. Liquid biopsies have transformed cancer detection in several key ways:
Than traditional tissue biopsies
Than imaging methods
Of cancer heterogeneity
Response over time 1
The power of liquid biopsies lies in their ability to detect circulating tumor DNA (ctDNA)—fragments of genetic material that tumors shed into the bloodstream. Even minute quantities of this DNA can reveal the genetic mutations characteristic of cancer 1 .
In 2025, researchers at Johns Hopkins Medicine published a groundbreaking study that demonstrates the incredible potential of clinical chemistry in cancer detection. Their research showed that fragments of tumor DNA can appear in the bloodstream up to three years before a cancer diagnosis would typically be made using conventional methods 1 .
"Three years earlier provides time for intervention. The tumors are likely to be much less advanced and more likely to be curable"
The research team used highly accurate and sensitive sequencing techniques to analyze blood samples from participants in the Atherosclerosis Risk in Communities (ARIC) study, which had been collecting samples for decades. They focused on 26 participants who were diagnosed with cancer within six months after sample collection and 26 similar participants who remained cancer-free 1 .
The experimental procedure followed these key steps:
Identifying stored plasma samples from individuals who later developed cancer
Isolating cell-free DNA from blood plasma
Using advanced techniques to identify cancer-associated mutations
Applying computational methods and confirming findings
At the time of blood collection, eight of the 52 participants showed positive results on a multicancer early detection (MCED) test. All eight were diagnosed with cancer within four months following blood collection. For six of these individuals, researchers analyzed additional blood samples collected 3.1-3.5 years prior to diagnosis. Remarkably, in four of these cases, they could identify tumor-derived mutations in the earlier samples 1 .
The Johns Hopkins study produced compelling evidence that early cancer detection through blood tests is not only possible but potentially transformative. The key findings included:
| Time Before Diagnosis | Detection Rate | Participants |
|---|---|---|
| 0-6 months | 100% | 8/8 |
| 3-3.5 years | 67% | 4/6 |
| Aspect | Traditional Detection | Early Chemical Detection |
|---|---|---|
| Timing | After symptoms appear | Years before symptoms |
| Tumor size | Often large | Microscopic |
| Treatment options | Limited | Extensive |
"This study shows the promise of MCED tests in detecting cancers very early, and sets the benchmark sensitivities required for their success"
The implications of this research are profound. As Dr. Nickolas Papadopoulos, another senior author, noted: "Detecting cancers years before their clinical diagnosis could help provide management with a more favorable outcome" 1 . However, he also acknowledged that further research is needed to determine the appropriate clinical follow-up after a positive test.
Modern clinical chemistry relies on a sophisticated array of technologies and reagents to detect cancer at its earliest stages. Here are some of the most important tools powering this revolution:
Function: NGS technologies allow researchers to sequence millions of DNA fragments simultaneously, identifying cancer-associated mutations even when they represent only a tiny fraction of the total DNA in a blood sample. This extreme sensitivity is crucial for early detection when ctDNA levels are minimal 1 5 .
Function: ELISA tests use antibodies to detect and quantify specific proteins in blood samples. For example, they can measure prostate-specific antigen (PSA) for prostate cancer screening or cancer antigen 125 (CA-125) for ovarian cancer monitoring. Recent advances have improved their sensitivity and specificity for cancer detection 6 7 .
Function: This technology identifies molecules based on their mass-to-charge ratio, allowing researchers to detect metabolic changes associated with cancer. It's particularly useful for identifying new biomarkers and understanding cancer metabolism 7 .
Function: AI algorithms analyze complex biomarker patterns that might be invisible to human researchers, identifying subtle signatures of early cancer. As noted in one review, "AI-facilitated imaging diagnostics using a range of modalities such as computed tomography, magnetic resonance imaging, positron emission tomography, ultrasound, and digital pathology" are enhancing early cancer detection 5 .
| Reagent | Function | Example Applications |
|---|---|---|
| Specific antibodies | Bind to and detect cancer-associated proteins | ELISA tests for protein biomarkers |
| DNA probes | Identify mutant DNA sequences characteristic of cancer | Genetic tests for hereditary cancer risk |
| Fluorescent dyes | Label molecules of interest for visualization and quantification | Flow cytometry analysis of cancer cells |
| Sequencing primers | Initiate DNA amplification for mutation detection | NGS-based liquid biopsy tests |
| Reference standards | Provide baseline measurements for calibration and quality control | Ensuring test accuracy across laboratories |
The future of cancer detection lies in combining multiple technologies—liquid biopsies, imaging, and medical history—with AI integration. As Katie Robertson, Ph.D., oncology network lead at Roche Diagnostics, explains: "Integration of AI in digital pathology can assist in pattern recognition, improve scoring subjectivity, maximize patient identification, automate routine tasks and support diagnostic decision-making" 9 .
AI algorithms are increasingly able to analyze complex data sets from multiple sources to identify subtle patterns indicative of early cancer. This approach promises to further improve detection accuracy while reducing false positives 5 .
One of the most exciting developments is the creation of tests that can screen for multiple cancers simultaneously. These MCED tests analyze patterns of DNA methylation, protein biomarkers, or other signals to detect various cancer types from a single blood draw. The Johns Hopkins study represents an important step toward making these tests a clinical reality 1 .
Researchers continue to discover new biomarkers that improve early detection. For example, a 2025 study evaluated STARD3 levels in patients with breast and prostate cancer, finding significantly lower levels in cancer patients compared to healthy controls 6 . While the clinical utility of STARD3 requires further investigation, it illustrates how new biomarkers continue to emerge.
Future tests will likely achieve even greater sensitivity, detecting cancer at earlier stages, while also improving specificity to reduce false alarms. As noted in one study, establishing target sensitivity and specificity values is crucial for developing clinically useful biomarkers .
Clinical chemistry has evolved from a supporting role in medicine to a frontline defense against cancer. By detecting molecular changes years before tumors form or symptoms appear, clinical chemists are providing what may be our most powerful weapon in the fight against cancer: the gift of time.
As we've seen through groundbreaking research like the Johns Hopkins study, the ability to detect cancer three years before clinical diagnosis represents a paradigm shift in oncology. This early warning system enables interventions when cancer is most vulnerable, potentially saving countless lives through earlier treatment.
The future of cancer detection lies not in a single technology but in the integration of multiple approaches—liquid biopsies, advanced imaging, artificial intelligence, and novel biomarkers—all guided by the principles of clinical chemistry. As these technologies continue to advance, we move closer to a world where cancer is detected not when it announces itself through symptoms, but when it first whispers its presence in our bloodstream.
"This study shows the promise of MCED tests in detecting cancers very early, and sets the benchmark sensitivities required for their success"
Indeed, clinical chemistry has set a new benchmark not just for sensitivity, but for hope in the ongoing battle against cancer.