Use of ctDNA Will Make Inroads in 2023 and Beyond

The potential for circulating tumor DNA (ctDNA) in early diagnosis, screening, and prevention can sometimes be overlooked by the oncology community because many of our patients present in our clinics and academic cancer centers with advanced-stage disease. However, the tremendous scientific developments in ctDNA, including genetic and epigenetic alterations, which are detectable in the blood—the so-called liquid biopsy—or multicancer early detection (MCED) tests, represent a revolution that seems to be rapidly emerging on the horizon.

How many times has a patient asked each of us, “Doctor, don’t you have a blood test for my cancer yet?” Recently, the National Cancer Institute (NCI) established some guidance on the MCED blood screening tests, which have begun to proliferate and are available in clinical trials, large health systems, and, shortly, in the commercial marketplace as a reimbursable test.

Many questions remain: Which is the appropriate at-risk population to be screened for the most efficacious application hat is the important algorithm to investigate when a positive test arises to confirm a true positive Conversely, how does one address a false-positive and avoid the cascade of potential costs, complications, and anxiety associated with false-positives or false-negatives?

Given the 33% reduction in cancer mortality since 1991 that was recently announced in the National Cancer Institute’s annual cancer report to the nation, the screening and prevention fi eld loos to these MCE tests as a dramatic new adjunct to assist in detecting early-stage disease, as opposed to later stages, where the oncology community, unfortunately, sees most of its patients.

Separately, the use of ctNA earlier in tumor surveillance, after definitive therapy to detect tumor recurrence or progression and to monitor efficacy and drug resistance, enables previously unimaginable liuid biopsies that are often obtained by a simple blood draw. Monitoring resistant genomic alterations or, in the case of virus-induced cancers, the recidivistic tumor regrowth after therapy, might permit implementation of more targeted, effective therapies sooner.

Thus, with strong support and advocacy, funding from the NCI, investments from commercial entities in the science and the validation of these tests, and further developments in clinical utility, the early-diagnosis fi eld should accelerate in 2023 and beyond. These much more durable cases that also are easier and less expensive to treat and cure, with higher quality of life and less morbidity, provide a sweet spot, warranting our attention and our participation.