Previous research has shown that nonsteroidal antiinflammatory drugs (NSAIDs), including aspirin and COX-2 inhibitors, may reduce the risk of developing colon cancer. A recent CALGB/SWOG study revealed that adding celecoxib to FOLFOX chemotherapy improved disease-free survival in patients with stage III colon cancer who tested positive for circulating tumor DNA (ctDNA) after surgery. The research was presented by Jonathan Nowak, MD, PhD, at the 2025 ASCO Gastrointestinal Cancers Symposium in San Francisco. Dr. Nowak is a molecular and gastrointestinal pathologist at the Dana-Farber Cancer Institute in Boston.
CALGB/SWOG 80702 Study
This analysis of a subset of the patients from CALGB/SWOG 80702 was conducted to learn whether a blood test to detect ctDNA could identify patients who were more likely to have a recurrence of cancer. This analysis also tested whether celecoxib was a helpful treatment for patients whose blood tested positive for ctDNA.
Key Findings
Of the 1,011 patients who had ctDNA testing performed, 189 (18.7%) had blood samples that tested positive for ctDNA. After 3 years, 86.6% of patients who were ctDNA-negative had no cancer growth. In comparison, 36.8% of patients who were ctDNA-positive had no cancer growth.
Patients who were ctDNA-negative who took celecoxib did not have a statistically significant improvement in disease-free survival when compared with a placebo. However, in patients who were ctDNA-positive, celecoxib significantly improved disease-free survival when compared with a placebo.
After 3 years, 44.1% of patients who were ctDNA-positive and took celecoxib had no cancer growth. In comparison, 26.6% of patients who were ctDNA-positive who took a placebo had no cancer growth.
Patients who were ctDNA-positive who took celecoxib had a 37% lower risk of all-cause mortality than patients who had ctDNA-positive disease and received a placebo.
“Our results suggest that a blood-based biomarker test looking at ctDNA to see if any tumor cells remain right after a patient has surgery to remove their primary colon cancer could help determine whether they should take an oral drug that would help prevent cancer recurrence. Our study provides a compelling demonstration that identifying patients with residual ctDNA doesn’t just provide prognostic information but also provides information that can help select an accessible therapy that may help patients live longer,” said Dr. Nowak.
Researchers will continue to study additional biomarkers that may help select patients who may benefit from celecoxib and will also study whether longer chemotherapy use is better for patients with ctDNA-positive disease. They will also continue to study the biology of how reducing inflammation by COX-2 inhibition helps to prevent colon cancer from recurring.
ASCO Perspective
“Testing patients with stage III colon cancer for ctDNA following surgery is a low-risk procedure that is fairly simple to complete. Many patients may be interested in this procedure if given the opportunity. It’s important for oncologists to be aware of these findings so they can have risk-benefit conversations with their patients,” said Laura Vater, MD, MPH, of Indiana University Simon Cancer Center.
Disclosure: The CALGB/SWOG 80702 study was funded by the National Cancer Institute, Alliance Foundation, and Natera. For full disclosures of all study authors, visit ASCO.org.
