Dr. Azzi on the Utility of Signatera as a Preferred ctDNA Assay in CRC

Georges Azzi, MD, co-director, Department of Hematology/Oncology, Prostate Cancer, Holy Cross Health, discusses the utility of the Signatera circulating tumor DNA (ctDNA) assay as a preferred test in colorectal cancer (CRC). 

The CIRCULATE-Japan study is the largest prospective tumor-informed ctDNA study conducted to date. The trial analyzed patients with stage II to IV resectable CRC with the goal of refining adjuvant therapy. Moreover, results from the study underscored the utility of the Signatera assay, which is associated with a 95% presurgical detection rate, Azzi says. At 4 weeks, the results demonstrated that patients with stage I to III disease who were ctDNA positive postoperatively had a hazard ratio of 24.4, Azzi says.  

Moreover, based on the ctDNA assay having validated data available and demonstrating utility for the detection of metastatic disease, the Signatera assay is being widely utilized by a variety of groups, such as Medicare, in the advanced cancer setting to monitor the molecular tumor burden, Azzi explains. 

If patients are responding to therapy, they will have a decrease in theirmolecular tumor burden. Moreover, the Signatera assay can identify that decrease at 6 weeks after treatment initiation vs many months with conventional imaging, Azzi adds. The assay presents the ability to detect responses or progression, as well as the ability to differentiate between pseudo-progressionand progression, which is important when utilizing immunotherapy, Azzi concludes.