What Is MCED Testing?
Currently under study, multicancer early detection (MCED) tests have the potential to fill gaps in the screening process for some cancers, consequently leading to earlier diagnoses for cancers historically diagnosed at later stages because of a lack of screening options. MCED tests use various methods to detect multiple cancers from one blood sample (https://doi.org/10.3390/cells12060935), such as methylation-based assay, which analyzes methylation patterns in cell-free DNA. In cancer cells, hypermethylation may silence tumor suppressor genes in the early stages of cancer growth. DNA hypermethylation has become a promising biomarker for early cancer detection.
What the Research Says
The traditional path to a cancer diagnosis is identifying a suspicious lesion through routine recommended screening, conducting tissue sampling, and confirming a diagnosis. However, for some cancers such as colorectal, ovarian, and lung, screening or sampling is invasive or impossible (https://doi.org/10.3390/cells12060935) because of tissue location. MCED testing could allow providers and patients to combine routine cancer screening with test sampling (https://doi.org/10.1007/s40271-022-00589-5) to detect those difficult-to-diagnose diseases much earlier.
Early evidence for DNA methylation–based tests is encouraging. The Circulating Cell-Free Genome Atlas study of one test reported (https://doi.org/10.1016/j.annonc.2020.02.011) a false-positive rate (specificity) of less than 1% across the 50 cancer types tested. Further, the sensitivity (ability to positively detect the disease) was 55%.
In another study exploring patient perceptions, researchers found that (https://doi.org/10.1007/s40271-022-00589-5) 72% of patients wanted to couple their routine cancer screenings with an MCED test. The patients cited a desire for high sensitivity, fewer false negatives, and more true positives.
Implications for Practice and Research
MCED testing is not currently U.S. Food and Drug Administration approved, but nurses should prepare for patient questions about early study findings and the potential for the tests to make their way into practice after the evidence is established. Until then, nurses can reinforce patients’ awareness (https://www.cancer.org/healthy/find-cancer-early/multi-cancer-early-detection-tests.html) about the importance of participating in currently available cancer screening procedures (https://voice.ons.org/news-and-views/most-cancer-screening-guidelines-dont-disclose-potential-harms).
The Cancer Genome Atlas Program has a massive genomic database of more than 30 tumor types that has fueled biomarker discovery, and more MCED studies are underway (https://doi.org/10.3390/cells12060935):
- The STRIVE study is investigating MCED testing’s ability to detect breast cancer in women undergoing mammography screening procedures.
- SUMMIT is evaluating testing patients at high risk for lung cancer from a history of smoking.
- PATHFINDER is looking at implementing testing in practice, specifically the time and procedures required to diagnose a patient with cancer after receiving a positive test result.
- The REFLECTION study is exploring the test’s impact on healthcare professionals.
MCED testing has the potential to revolutionize the cancer screening process and dramatically improve patient outcomes after more research fine tunes the science.