According to data from the CALGB/SWOG 80702 trial, circulating tumor DNA (ctDNA) was highly prognostic of disease-free survival (DFS) and overall survival (OS) and may be predictive of the benefit of adjuvant celecoxib for DFS and OS.

These data were first presented by Jonathan A. Nowak, MD, PhD, Dana-Farber Cancer Institute, Boston, Massachusetts, at the 2025 American Society for Clinical Oncology (ASCO) Gastrointestinal Cancers Symposium.

In this phase 3 trial, 2526 patients with stage III colon cancer were treated with either 3 or 6 months of adjuvant 5-fluorouracil, leucovorin, oxaliplatin (FOLFOX) with or without celecoxib. After surgery and before the start of the adjuvant therapy, ctDNA assessment was done. It has previously been reported that the addition of celecoxib to FOLFOX did not significantly improve the DFS. Here, the prognostic and predictive value of ctDNA to identify a subpopulation of patients who may benefit from celecoxib.

There were 1011 patients who had ctDNA results. 189 of which were ctDNA positive (18.7%). ctDNA positivity was significantly associated with worse DFS (hazard ratio [HR], 6.52; P < .0001) and worse OS (HR, 6.26; P < .0001). The 3-year DFS rate was 86.6% for patients who were ctDNA negative, and 36.8% for those ctDNA positive. While there was not a significantly worse DFS associated with celecoxib vs placebo among patients who were ctDNA negative (HR, 0.75; P = .095), celecoxib significantly improved the DFS of patients who were ctDNA positive when compared to placebo (HR, 0.59; P = .004). The 3-year DFS rates of those patients who were ctDA negative were 87.7% and 85.5% respectively, and of those ctDNA positive, 44.1% vs 36.6%, respectively. There were similar results with OS among ctDNA negative patients (HR, 0.86; P = .49) and ctDNA positive patients (HR, 0.63; P = .028).

Dr Nowak et al, concluded, “These results suggest a potential role for ctDNA in determining which patients should consider celecoxib in addition to standard FOLFOX adjuvant therapy.” Dr Nowak commented further, “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.”

Source:

Nowak JA, Shi Q, Twombly T, et al. Prognostic and predictive role of circulating tumor DNA (ctDNA) in stage III colon cancer treated with celecoxib: Findings from CALGB (Alliance)/SWOG 80702. Presented at ASCO Gastrointestinal Cancers Symposium; January 23-25, 2025. San Francisco, CA. Abstract LBA14

New research explores blood test to determine prognosis, benefit of celecoxib in stage III colon cancer. News Release. American Society of Clinical Oncology. Accessed January 16, 2025. https://society.asco.org/about-asco/press-center/news-releases/new-research-explores-blood-test-determine-prognosis-benefit?cid=DM19308&bid=450425113