A recent study suggested that patients with colon cancer lived longer when taking aspirin.
Aspirin is a very interesting drug which has showed to reduce the risk of cardiovascular disease and colon cancer risk and is a great pain reliever. The mechanism of action is the inhibition of an enzyme called COX-2.
However aspirin also inhibits COX-1 which is thought to be responsible for some of its side effects such as stomach ulcers, bleeding disorders and kidney problems. Therefore major pharmaceutical companies have developed specific COX-2 inhibitors to have the great benefits but not the side effects. These drugs are known as Celebrex and Vioxx.
It was shocking to see the results from the large VICTOR trial testing Vioxx in patients with colon cancer who had successful resection and adjuvant chemotherapy. This trial enrolled 1167 patients and 23 cardiovascular thrombotic events occurred (heart attacks), 16 were in the Vioxx group and 7 in the placebo group. Statistically this was highly significant making it an estimated risk of 2.66 which means increase by 266 percent. These data were the end of the COX-2 inhibitors in the chemoprevention world.
The newest study on aspirin shows clearly that the inhibition of these enzymes may benefit patients with active disease. Dr. Chan showed in 1300 patients with colon cancer were nearly 30% less likely to die from their cancer.
How aspirin works, we don’t know. It can prevent blood clots, but COX-2 is directly involved in inflammation which can be part of cancer, and invasion and metastases. These data warrant further studies of the role of these drugs for patients with colon cancer.
I discuss and use baby aspirin for many of my patients but also let them know about the potential risk factors. For example someone with bleeding problems or stomach ulcer or kidney function problems would be not great candidate. However for patients on Avastin I do consider aspirin to potentially reduce the risk for heart attack and strokes.
Please discuss these findings with your treating oncologists.
September 09, 2009 at 4:12 pm, Jerryl said:
Dr. Lenz
My husband was recently diagnosed with stage IV colon cancer with mets to the liver and is on Avastin. His oncologist recommended that he avoid aspirin because of the liver involvement. Is this medicinal dose of aspirin OK for him?
September 09, 2009 at 4:26 pm, Heinz-Josef Lenz said:
it should be but as you can imagine dont know the full history or medical issues of your husband, but some physicians even use aspirin to reduce risks of heart attacks and strokes associated with avastin, if his liver function is not good leading to increased bleeding, aspirin should not be given, please clarify with your oncologist. HJL
September 10, 2009 at 2:45 pm, Michael Grinberg, M.D. said:
Could you please cite Dr. Chan’s original article you referred to and rely upon?