A study announced by Natera, the makers of a molecular residual disease (MRD) test called Signatera, showed the test’s ability to identify patients with stage II-IV colorectal cancer who are at an increased risk for recurrence after surgery. This information can help oncologists predict who is likely to benefit from chemotherapy after surgery, which is called adjuvant chemotherapy.

MRD tests look for tumor DNA in a patient’s blood. The presence of tumor DNA in the blood, or circulating tumor DNA (ctDNA), means there is a higher risk of cancer returning, according to Natera. 

The study monitored 1,039 patients with resectable CRC — cancer that can be removed with surgery — using Signatera. It notes that more than 30% of patients with resectable colorectal cancer have a recurrence. Findings from the study support the use of Signatera MRD ctDNA testing to identify patients who are at increased risk of recurrence and are likely to benefit from adjuvant chemotherapy.

According to a press release, the Signatera MRD ctDNA study’s results showed: 

• Patients who tested MRD positive four weeks after surgery (18%)  significantly benefited from adjuvant chemotherapy. 
• Signatera MRD positivity after surgery was the most significant risk factor for recurrence. 
• Patients who were treated with adjuvant chemotherapy and had ctDNA clearance afterward were shown to have superior disease-free survival compared to those who did not have ctDNA clearance. 

“Until now, oncologists did not have adequate tools to determine which colorectal cancer patients are likely to benefit from adjuvant systemic therapy,” said the study’s principal investigator, Dr. Takayuki Yoshino, of the National Cancer Center Hospital East, Kashiwa, Chiba, Japan. “This study provides strong evidence that Signatera MRD-positive patients will benefit significantly from adjuvant therapy, while MRD-negative patients may be safely observed, regardless of clinical or pathological stage.”

Minetta Liu, M.D., chief medical officer of oncology at Natera, added that this study is “practice-changing,” and the company looks forward to making Natera accessible to all patients in the U.S. and worldwide. 

If you are interested in the Signatera MRD test, speak with your healthcare provider or contact Natera. View Natera’s press release for more information.