Advancing multi cancer early detection
As multi-cancer early detection (MCED) testing gains momentum, experts are honing their focus on what comes next for patients with a positive MCED test result. Understanding the diagnostic pathways available after testing are an important aspect of minimizing harm, patient anxiety, and unnecessary interventions.
During a recent discussion, Becker’s Healthcare and Exact Sciences hosted leaders from Johns Hopkins Medicine and Exact Sciences to talk about how imaging plays a critical role in guiding next steps after a positive MCED result by confirming and localizing malignancies.
Here are four key takeaways from the conversation:
1. Positive MCED tests follow imaging-based diagnostic pathways or molecular tumor of origin (TOO) diagnostic pathways.
There are two diagnostic pathways following a positive MCED test result. One is the imaging based diagnostic pathway, and the other is the molecular tumor of origin (TOO)/cancer signal of origin (CSO) diagnostic pathway.
While some MCED tests may provide a predicted TOO/CSO, the molecular prediction may be inconclusive or incorrect. In these cases, patients with a positive MCED test may follow up with a targeted imaging procedure and then need to undergo subsequent whole-body imaging. In contrast, using whole-body imaging for diagnostic confirmation of a positive MCED test can offer an efficient workflow solution.
Most patients will require cross-sectional imaging regardless of whether a TOO signal is conclusive, explained Tomasz Beer, MD, Chief Medical Officer and VP of MCED at Exact Sciences. He cited the landmark DETECT-A study published in Science, noting that in this prospective, interventional study of over 10,000 participants, a CT-based diagnostic pathway localized all 26 detected cancers and provided reliable resolution for false positive MCED test results.
Enabling maximally conclusive diagnoses with optimum efficiency remains a critical component of improving patient care and the overall patient experience.
“Fewer diagnostic procedures is not just more efficient, less expensive, and safer — but it’s faster,” Dr. Beer said. “When things are faster, patients get to their answers more quickly and can rest easy if they’re cancer free, or get a robust answer if they have to face cancer.”
2. Imaging-based pathways are predicted to reduce diagnostic burden for patients with positive MCED tests.
Dr. Xiting Cao, the Director of Health Economics and Outcomes Research at Exact Sciences, shared findings from a recent modeling study published in JNCI Cancer Spectrum that compared the efficiency and impact of imaging-first diagnostic pathways for positive MCED result confirmation to those diagnostic pathways guided by molecular predictions.
In this study, researchers explored all diagnostic procedures that would provide clinical information essential for cancer treatment. Modeling data indicated that patients with false positive MCED test results who follow an imaging-based diagnostic pathway are expected to undergo 2.40 procedures, while patients with false positive MCED test results who follow a molecular TOO/CSO diagnostic pathway are expected to undergo 4.05 procedures. The diagnostic burden was higher for the molecular TOO/CSO strategy across all positive predictive values and localization performances.
These findings also highlight the importance of efficient care coordination to ensure timely clinical evaluation and diagnostic procedures following a positive MCED test result, helping to minimize diagnostic delays.
3. Imaging scalability improves care for patients with positive MCED test results
Elliot Fishman, MD, Professor of Radiology, Oncology and Surgery at Johns Hopkins Medicine emphasized that computed tomography (CT) is well-positioned to support diagnostic resolution following a positive MCED result due to both its wide availability and improved precision.
“People are not going to be able to travel hundreds of miles or 50 miles even,” Dr. Fishman said, acknowledging the critical nature of accessible imaging. He also noted that advanced techniques like photon-counting CT and AI are improving resolution while reducing radiation exposure. “One of the biggest gains that you’re going to see in the short term and long term is the accuracy of imaging, because AI is being used to improve the accuracy of detection.”
4. The integration of MCED testing and efficient workflows for positive results has the potential to enhance care
To ensure high-value use of imaging, Dr. Beer stressed the importance of patient education and clear care pathways. The Cancerguard™ EX test, Exact Sciences’ MCED test, is designed with a specificity of 98%. If successfully integrated into clinical workflows, MCED testing and prompt imaging could dramatically reshape cancer detection and early intervention over the next five years.
Dr. Cao’s research shows widespread use of annual MCED testing could reduce stage IV cancer incidence by 42% and cancer-specific mortality by 18% within a decade.
“To really achieve a significant reduction in the burden that cancer places on all of us, we must advance early detection,” remarked Dr. Beer. “This is a very promising way to pursue that.”
Disclaimer: The webinar, “Seeing Beyond the Signal: Imaging After a Positive MCED Test,” and this article were sponsored by Exact Sciences. The content of this article is not medical advice.