Single cancer early detection tests exist today for four common cancers.* Generally speaking, early detection works, meaning that these screening tests can save lives and reduce cancer deaths. However, most cancers currently go undetected in their early stages because there are no screening tests for most cancers.
Becker's Hospital Review recently spoke with Tom Beer, MD, Chief Medical Officer and Vice President, Multi-Cancer Early Detection (MCED) at Exact Sciences, about the potential for multi-cancer early detection tests to reduce morbidity and mortality from cancer worldwide.
Note: Responses edited for length and clarity.
Question: Have we made enough progress with cancer detection and prevention in the United States? Where are we on this continuum?
Tom Beer: We have made real progress with single-cancer early detection tests. However, ongoing challenges exist with adherence to screening recommendations, as well as with disparities in access to, and utilization of, screening. There's still work to be done on those fronts. The biggest need and opportunity lie with the 70 percent of incident cancers for which we don't currently have any screening tests.1† Those cancers account for more than two-thirds of U.S. cancer deaths1, which I refer to as the "un-screen able cancers." That's where multi-cancer early detection may come into play.
There are too many un-screen able cancers to approach them one at a time. We can't close the gap by developing dozens of individual screening tests. The technology that underlies multi-cancer early detection is the best promise for closing the gap and substantially expanding the number of cancers that we can detect early.
This opportunity has been widely recognized — the National Cancer Institute, the scientific community and even the White House and the Moonshot Program are all focused on the potential of multi-cancer early detection.
Q: What are advances in science and technology that will make early detection through blood tests and other means possible?
TB: Over the last several decades, scientists have come to understand the molecular or biologic underpinnings of cancer. We understand that DNA mutations, DNA methylation (a chemical modification that silences DNA), abnormal proteins and other biomarkers are altered in cancer.
We've also developed technologies to detect very small quantities of these abnormal biomarkers in cancer patients' blood. Understanding cancer biology, knowing what to look for and measuring and detecting those things at very low concentrations in the blood are what make multi-cancer early detection possible. The tests under development rely on measuring biomarkers that come from cancer and are circulating in the blood.
Q: What are learnings so far from early data derived from multi-cancer early detection testing?
TB: At Exact Sciences, we carried out the first prospective interventional study of a multi-cancer early detection test. This test, called CancerSEEK was evaluated in an average risk population. Between 2017 and 2019, this study enrolled over 10,000 women, and results were published in 2020.2
The CancerSEEK test involved two biomarker classes. Those were DNA mutations and proteins and demonstrated the power of this approach for detecting a variety of cancers, including several cancers at early stages, where the intent of treatment is to cure as many patients as possible. The study also established a rapid and efficient pathway for evaluating patients who have a cancer signal detected through multi-cancer early detection. We are using the learnings from this study to develop improvements in the detection and deployment of an efficient diagnostic pathway as we look to launch our next set of studies.
Q: Can multi-cancer early detection testing help close gaps related to disparities in health equity?
TB: We know that in the past, technological advances have often led to increases in disparities, rather than decreases, at least initially. That's because new technologies may not be equally accessible to everyone.
A unique feature of the multi-cancer early detection tests currently in development is that they are a simple blood test, which can be made broadly available throughout all communities in the country. I think the tests have significant potential to reduce disparities if we are thoughtful and deliberate to make that so. We have every intention of working toward that goal as we deploy the studies needed to evaluate the test and if successful, deploy the test clinically.
Q: In the longer term, what does the implementation of effective cancer early detection testing look like for health systems?
TB: Since many of these tests are still under development, they aren't yet FDA approved or routinely available. If you think about the potential future impact on health systems, there will be an initial period of learning for the tests. If the tests are deployed, one would expect a significant shift in the proportion of cancers that are that are diagnosed at earlier stages because of early detection tests.
We would anticipate that health systems would see a larger proportion of newly diagnosed cancer patients presenting with earlier stage diseases. Clinicians could offer patients therapy with intent to cure or more effective therapies — hopefully ones associated with less toxicity, fewer adverse outcomes, and more promising levels of long-term cancer control.
Q: What's next for multi-cancer early detection testing at Exact Sciences?
TB: Exact Sciences recently reported the results of an updated four biomarker class test.3 This is a single blood test that looks for four different classes of abnormalities associated with cancer. Our plan is to finalize the development of that assay and lock the assay in another set of samples from a study called Ascend II.
We then plan to launch a pivotal large-scale interventional trial. The trial will be randomized and designed to seek FDA approval for the test. We also anticipate launching additional studies to gather real-world evidence about how our test is performing during real-world use.
*Cancers that have standard of care screening: breast, cervical, colorectal and lung (high-risk)
†Calculated using estimated new cases of cancers that have standard of care screening: breast, cervical, colorectal and lung (high-risk for each sex) against all sites
References:
1. Siegel; RL, Miller KD, Fuchs HE, Jemal A. Cancer statistics, 2022. CA Cancer J Clin. 2022;72:7-33.
2. Lennon AM, Buchanan AH, Kinde I, et al. Feasibility of blood testing combined with PET-CT to screen for cancer and guide intervention. Science. 2020;369(6499).
3. Douville C, Nobles C, Hwang GH, et al. Multi-cancer early detection through evaluation of aneuploidy, methylation, mutation, and protein biomarkers in plasma. Presented at ESMO Congress in Paris, France on September 10, 2022.