The Alliance for Clinical Trials in Oncology today announced the results of a data analysis from a randomized phase III clinical trial involving patients with stage III colon cancer, which found that adding the drug celecoxib to treatment after surgery might help those who still have traces of cancer in their blood. The analysis showed that patients with signs of cancer in their blood measured by Signatera™, a circulating tumor DNA (ctDNA) test, tended to have worse outcomes. However, those who took celecoxib after surgery had a much better chance of staying cancer-free. These results are being presented in a late-breaking abstract and highlighted in the press program during the 2025 American Society of Clinical Oncology Gastrointestinal Cancers (ASCO GI) Symposium, in San Francisco, CA.
"These findings highlight the critical role of ctDNA status in predicting cancer recurrence and chemotherapy benefit for patients with stage III colon cancer," said Jonathan Nowak, MD, PhD, lead author and molecular and gastrointestinal pathologist at Dana-Farber Cancer Institute and Brigham and Women's Hospital. "For those with detectable traces of cancer in their blood after surgery, adding celecoxib to their treatment regimen may significantly improve disease-free survival, offering a new opportunity to enhance outcomes for this high-risk group."
The CALGB (Alliance)/SWOG 80702 trial assessed the benefit of adding celecoxib, a non-steroidal anti-inflammatory drug (NSAID), to FOLFOX chemotherapy in the postoperative treatment of stage III colorectal cancer (CRC) without selecting patients based on specific biomarkers. The trial also compared three-month versus six-month FOLFOX treatment as part of the larger International Duration Evaluation of Adjuvant Therapy (IDEA) collaboration. The original prospective trial enrolled 2,526 patients between 2010 and 2015. While the addition of celecoxib did not significantly improve disease-free survival ( results were published in 2021), NSAIDs have shown potential benefits in certain CRC subgroups, such as reducing the risk of developing precancerous colon polyps.
According to Jeffrey Meyerhardt, MD, MPH, senior author and co-director of the Colon and Rectal Cancer Center at Dana-Farber Cancer Institute, in the original prospective celecoxib clinical trial designed 10 years ago, patients were evaluated before and after surgery using imaging, which can show where cancer cells have gathered but has limited ability to detect smaller or microscopic clusters. Current ctDNA tests offer a more sensitive way to detect whether cancer remains after surgery by identifying tiny fragments of tumor DNA in the blood.
The subsequent data analysis to be presented at ASCO GI today includes 1,011 of 2,526 CRC patients with available post-surgery biobanked samples, and investigates the ability of Signatera to identify a subgroup of patients who may benefit from adding celecoxib to FOLFOX, as well as others who may not require six months of FOLFOX. Disease free-survival and overall survival are the study's primary and secondary endpoints, respectively.
Researchers performed ctDNA tests on blood samples taken after surgery. Their analysis revealed that those with positive ctDNA generally had worse outcomes. However, those with positive ctDNA tests who had been prescribed celecoxib with standard chemotherapy had significantly improved disease-free survival compared to those who took a placebo. For those who had negative ctDNA tests, there was no significant difference between those taking celecoxib versus placebo.
Both researchers state, "The analysis suggests that celecoxib with standard chemotherapy shows significant promise for patients with early-stage colon cancer who have residual disease after initial treatment. This evidence, along with findings from other ongoing studies, will help identify which patients might benefit from adding celecoxib to their standard treatment regimen."
