Blood Test Using ctDNA Identifies Colon Cancer Patients Who Benefit from Celecoxib Anti-Inflammatory Therapy
核心洞察
A blood test measuring circulating tumor DNA (ctDNA) can identify stage III colon cancer (搜索) patients who benefit from adding celecoxib to standard chemotherapy after surgery.
Patients testing positive for ctDNA after surgery who received celecoxib showed nearly doubled disease-free survival at three years (41% vs 22.6%) compared to placebo.
The findings from the CALGB/SWOG 80702 trial involving 940 patients could enable personalized treatment decisions and avoid unnecessary medication for patients unlikely to benefit.
A simple blood test measuring circulating tumor DNA (ctDNA) can identify which stage III colon cancer (搜索) patients will benefit from anti-inflammatory medication added to standard chemotherapy, according to new research published in JAMA Oncology. The findings from the Alliance for Clinical Trials in Oncology study could transform treatment decisions for thousands of patients annually.
ctDNA Test Predicts Treatment Response
Researchers analyzed data from the CALGB/SWOG 80702 phase 3 trial, examining postoperative ctDNA status in 940 patients with stage III colon cancer (搜索) who had undergone curative resection. Patients were randomized to receive either celecoxib or placebo alongside fluorouracil, leucovorin, and oxaliplatin (FOLFOX (搜索)) chemotherapy.
"We've known that NSAIDs may help prevent recurrence in some patients with colon cancer (搜索), but until now, we didn't know how to identify them. Measuring circulating tumor DNA levels after surgery using this blood test has the potential to change that," said lead study author George Q. Zhang, MD, MPH, a general surgery resident at Brigham and Women's Hospital.
The study used the Signatera ctDNA assay to detect minimal residual disease by analyzing tiny fragments of cancer DNA that remain in the blood after surgery. Of the 940 patients analyzed, 767 tested ctDNA negative and 173 tested ctDNA positive.
Dramatic Survival Improvements in High-Risk Patients
ctDNA positivity strongly predicted worse outcomes, with patients showing an adjusted hazard ratio of 6.12 for disease-free survival and 5.86 for overall survival compared to ctDNA-negative patients. However, among ctDNA-positive patients, celecoxib treatment produced substantial benefits.
Three-year disease-free survival reached 41.0% with celecoxib versus 22.6% with placebo, representing an adjusted hazard ratio of 0.61. Five-year overall survival was 61.6% for celecoxib-treated patients compared to 39.9% in the placebo group, with an adjusted hazard ratio of 0.62.
"In patients who tested ctDNA positive, the addition of celecoxib compared to placebo nearly doubled disease-free survival over three years," the researchers reported.
No Benefit for Low-Risk Patients
In contrast, ctDNA-negative patients showed no significant survival benefit from celecoxib. Their outcomes remained favorable regardless of treatment assignment, with five-year overall survival exceeding 91%. Point estimates for 3-year disease-free survival were 86.5% for ctDNA-negative patients versus 33.7% for ctDNA-positive patients.
The findings remained consistent when stratified by microsatellite instability status and PIK3CA mutational status. For microsatellite stable tumors, ctDNA-positive patients in the celecoxib group achieved an estimated 3-year disease-free survival of 39.7% versus 22.3% in the placebo group.
Addressing Unmet Medical Need
Colon cancer (搜索) affects approximately 110,000 new patients annually in the United States, with up to 40% of stage III patients experiencing recurrence despite surgery and chemotherapy. The CALGB/SWOG 80702 trial originally enrolled more than 2,500 patients to determine if adding celecoxib to chemotherapy improved survival.
"The initial trial didn't definitively confirm our hypothesis; however, we saw that some patients did benefit from adding celecoxib and we then sought to identify them," said study chair Jeffrey Meyerhardt, MD, MPH, a medical oncologist at the Dana-Farber Cancer Institute.
Celecoxib belongs to the NSAID class of medications and is a selective cyclooxygenase-2 (搜索) (COX-2 (搜索)) inhibitor commonly prescribed for arthritis pain. Researchers have long suspected that anti-inflammatory properties in NSAIDs could prevent colon cancer (搜索) recurrence since inflammation plays a role in cancer growth, but clinical trials have not shown clear benefits for all patients.
Clinical Implementation Potential
The ctDNA test involves a simple blood draw followed by gene sequencing analysis. For healthcare payers, the ability to identify patients who benefit from celecoxib could support more targeted coverage policies, avoiding unnecessary drug costs and exposure in patients unlikely to benefit.
Given celecoxib's established safety profile and relatively low cost compared to newer targeted agents, its use in a biomarker-defined subgroup may represent a cost-effective strategy for stage III colon cancer (搜索) treatment.
"ctDNA may help inform decision-making by identifying a subset of patients who benefit most from adjuvant COX-inhibition alongside conventional chemotherapy, offering opportunities for personalized approaches in CRC treatment," Zhang noted.
The researchers emphasized that additional prospective research will be necessary to further validate these encouraging results before widespread clinical implementation.