A recent study published in JAMA Oncology suggests that a blood test could help doctors determine which colon cancer patients would benefit from anti-inflammatory medication, specifically celecoxib, alongside chemotherapy after surgery. The findings are based on data from an Alliance for Clinical Trials in Oncology study and may lead to more personalized treatment plans.
Colon cancer remains one of the most prevalent cancers in the United States, with about 110,000 new cases each year. Despite surgery and chemotherapy, recurrence occurs in up to 40% of patients diagnosed with stage III disease. Celecoxib is part of the NSAID family, commonly used to reduce inflammation and pain.
Previous research has indicated that NSAIDs might prevent colon cancer recurrence due to their anti-inflammatory effects. However, clinical trials have not shown uniform benefits for all patients, making it unclear who should receive these drugs.
The new analysis focused on circulating tumor DNA (ctDNA), small fragments of cancer DNA found in the blood after surgery. Patients who tested positive for ctDNA faced a higher risk of their cancer returning. For these high-risk individuals, adding celecoxib to chemotherapy significantly improved survival rates. In contrast, those without ctDNA did not experience added benefits from celecoxib and could avoid unnecessary medication. Clinicians measure ctDNA using a blood sample analyzed through gene sequencing.
"We've known that NSAIDs may help prevent recurrence in some patients with colon cancer, 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 main goal of CALGB (Alliance) 80702 was to determine if adding celecoxib to chemotherapy after surgery for colon cancer improved survival," said study chair Jeffrey Meyerhardt, MD, MPH, a medical oncologist at the Dana-Farber Cancer Institute. "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. This study identified a subset of patients that had detectable ctDNA after surgery as a group that benefited from adding celecoxib to chemo after surgery."
Supported by the National Cancer Institute, CALGB (Alliance) 80702 enrolled over 2,500 stage III colorectal cancer patients who had undergone tumor removal surgery. The current analysis examined ctDNA samples from 940 participants—767 were ctDNA negative while 173 were ctDNA positive. Among those testing positive for ctDNA post-surgery, adding celecoxib nearly doubled three-year disease-free survival rates compared with placebo: 41% versus 22.6%. Five-year overall survival was also higher at 61.6% for those receiving celecoxib compared with 39.9% for placebo recipients.
"Although these results are very encouraging, additional prospective research will be necessary to further validate them," Dr. Zhang added.
