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Cancer screening has taken a significant leap forward with the introduction of advanced blood tests like Trucheck™ and Galleri®. These innovative screening methods aim to detect cancer at its earliest stages, providing vital information for timely interventions and improved outcomes. In this blog, we will compare Trucheck™ and Galleri®, exploring their scientific principles, advantages, and considerations, to help you make informed decisions about cancer screening.

Trucheck™: Harnessing Circulating Tumour Cells (CTCs)

Trucheck™, developed by Datar Cancer Genetics, focuses on detecting circulating tumour cells (CTCs) and circulating ensembles of tumour-associated cells (C-ETACs) in peripheral blood samples. By employing primary negative enrichment, Trucheck™ enables the survival of malignant cells while allowing non-malignant cells to undergo apoptosis (programmed cell death). The subsequent analysis of tissue-specific markers on these cells helps identify cancer types and their likely organ of origin. Trucheck™ offers high sensitivity, specificity, and an overall advantage in detecting over 70 solid organ cancers.

Galleri®: Uncovering Methylation Patterns in cfDNA

Galleri®, another groundbreaking blood test, detects over 50 types of cancer and predicts the origin of cancer signals with high accuracy. This test examines the methylation patterns of cell-free DNA (cfDNA) found in the bloodstream. Methylation patterns, which regulate gene expression, can be altered in cancer, contributing to tumour growth. By leveraging next-generation sequencing (NGS) and machine-learning algorithms, Galleri® analyses the methylation patterns of cfDNA to identify cancer-specific abnormalities. These patterns provide valuable information about the presence and origin of potential cancers.

Detection Accuracy and Predictive Values:

Trucheck™ demonstrates an overall sensitivity ranging from 82.5% to 88.2% for different cancer types. It boasts a specificity of 99%, correctly identifying 99 out of 100 individuals without cancer. False positives occur at an estimated rate of 1% to 3% according to the studies available so far. Trucheck™ has been designed as a complement to, not replacement for, standard cancer screening, offering peace of mind to individuals with negative results while prompting further tests or referrals for those with positive results.

Galleri®, as demonstrated in the SYMPLIFY study, achieved a sensitivity of 66.3% overall, ranging from 24.2% for stage I cancers to 95.3% for stage IV cancers. This demonstrates Galleri’s ability to detect cancer signals across various stages but that it is most reliable with later-stage tumours. With a positive predictive value (PPV) of 75.5% and a negative predictive value (NPV) of 97.6%, Galleri®shows promise in accurately identifying individuals with cancer. The test’s specificity stands at 98.4%, further enhancing its precision in distinguishing cancer from non-cancer cases.

Availability and Clinical Trials:

Trucheck™ is available as an add-on service for patients undergoing health screening at Coyne Medical and several other private clinics in London and beyond. It may not be covered by healthcare insurance or the NHS prior to a formal cancer diagnosis. Further diagnostic procedures and referrals prompted by positive results may require self-payment.

On the other hand, Galleri® is currently being evaluated in clinical trials and is not widely available outside of these trials. The SYMPLIFY study demonstrated its potential in a cohort of patients referred for diagnostic investigations related to suspected gynaecological, lung, and gastrointestinal cancers. 

Considerations and Future Implications:

Both Trucheck™ and Galleri® have the potential to revolutionise cancer screening, but it’s important to consider certain factors. Trucheck™ offers a broader range of tests for different cancer types, while Galleri’s focus lies in detecting over 50 cancer types. Trucheck™ uses CTCs and their clusters as biomarkers, primarily for solid organ malignancies, whereas Galleri® examines cfDNA methylation patterns.

While Trucheck™ and Galleri® boast impressive sensitivity, it’s crucial to understand that false negatives can still occur. Neither test can replace standard screening methods such as mammograms, colon cancer screening, or cervical screening. Additionally, the emotional impact and potential for anxiety associated with both tests’ results should be taken into consideration.

Looking ahead, the development of advanced blood tests like Trucheck™ and Galleri® brings us closer to a future where early cancer detection becomes a reality. These tests have the potential to complement existing screening methods, offering individuals a comprehensive and personalised approach to cancer prevention and treatment.

Trucheck™ and Galleri® blood tests represent groundbreaking advancements in cancer screening, utilising cutting-edge technologies and scientific understanding to improve early detection rates. Trucheck™ focuses on CTCs, while Galleri® examines cfDNA methylation patterns. Both tests demonstrate considerable accuracy and hold promise for transforming cancer diagnosis and treatment.

It is essential to consult with healthcare professionals to determine the most suitable screening approach based on individual risk factors, age, and personal medical history. By considering these innovative blood tests alongside standard screening methods, we move closer to a future where early cancer detection becomes the norm, leading to better outcomes and improved quality of life. Trucheck™ cancer screening blood test is available at Coyne Medical. Learn more on our website here.