PTGS2 and colorectal adenoma: Celecoxib failed to improve survival in patients with advanced non-small-cell lung cancer, metastatic prostate cancer, and HER2-negative breast cancer.25–27 However, celecoxib reduced tumour recurrence in colorectal adenomas.28 A meta-analysis showed that celecoxib was associated with better treatment responses in several types of cancer.29 However, most of these trials did not select patients using COX-2 or IL-1β levels.