However, serious cardiovascular events were significantly more frequent in the celecoxib-treated groups. Aspirin shows a similar (and possibly larger) protective effect, has demonstrated cardioprotective effects and is significantly cheaper, but no head-to-head clinical trials have compared the two drugs. Cancer treatment
Different from cancer prevention, cancer treatment is focused on the therapy of tumors that have already formed and have established themselves inside the patient. Many studies are going on to determine whether celecoxib might be useful for this latter condition. However, during molecular studies in the laboratory, it became apparent that celecoxib could interact with other intracellular components besides its most famous target, COX-2. The discovery of these additional targets has generated much controversy, and the initial assumption that celecoxib reduces tumor growth primarily by the inhibition of COX-2 became contentious.Certainly, the inhibition of COX-2 is paramount for the anti-inflammatory and analgesic function of celecoxib. However, whether inhibition of COX-2 also plays a dominant role in this drugs anticancer effects is unclear. For example, a recent study with malignant tumor cells showed celecoxib could inhibit the growth of these cells in vitro, but COX-2 played no role in this outcome; even more strikingly, the anticancer effects of celecoxib were also obtained with the use of cancer cell types that do not even contain COX-2. Karen Seibert and colleagues have published research showing antiangiogenic and antitumor activity of celecoxib in animal models.Additional support for the idea that other targets besides COX-2 are important for celecoxibs anticancer effects has come from studies with chemically modified versions of celecoxib.
However, it has a low (reportedly 4%) chance of inducing cutaneous reactions among persons who have a history of such reactions to aspirin or nonselective NSAIDs. NSAIDs may cause serious skin adverse events, including exfoliative dermatitis, Stevens-Johnson syndrome, and toxic epidermal necrolysis; events may occur without warning and in patients without prior known sulfa allergy. Use should be discontinued at first sign of rash (or any other hypersensitivity). Heart attack and stroke
A 2013 meta-analysis of hundreds of clinical trials found that coxibs (the class of drugs that includes celecoxib) increase the risk of major cardiovascular problems by about 37% over placebo. In 2016, a randomized trial provided strong evidence that treatment with celecoxib is not more likely to result in poor cardiovascular outcomes than treatment with naproxen or ibuprofen. As a result, in 2018 an FDA advisory panel concluded that celecoxib poses no greater risk for causing heart attacks and strokes than the commonly-used NSAIDs ibuprofen or naproxen and recommended that the FDA consider changing its advice to physicians regarding celecoxibs safety.The COX-2 inhibitor rofecoxib (Vioxx) was removed from the market in 2004 due to its risk. Like all NSAIDs on the US market, celecoxib carries an FDA-mandated "black box warning" for cardiovascular and gastrointestinal risk.