PTGS2 and carcinoma: COX-2 inhibitors, such as celecoxib and rofecoxib, have been studied as potentially effective treatment modalities due to their ability to decrease prostaglandin levels, which are generally higher in cancer patients. Aberrant prostaglandin production is linked to the adenoma-carcinoma sequence, during which adenomas turn dysplastic and accumulate enough damage to become malignant.