There are a number of possibilities of how aspirin and other NSAIDS might help protect against cancer. These are the most prominent current theories:
1) Inflammation may be involved in the development of ovarian cancer (OVCA). For example, there has been noted association between OVCA and pelvic inflammatory disease, and possibly exposure to environmental agents such as talc, which could cause chronic inflammation. Some scientists also think that ovulation itself could set up an inflammatory process. In any of these cases, aspirin and other NSAIDS would counter that inflammation.
2) COX-2 enzyme - This enzyme has been found in increased amounts in many tumors (again, it has mostly been studied in regards to colon cancer). There are a number of possible ways in which this enzyme might promote cancer. One possibility is that COX promotes angiogenesis - the development of the blood supply to the tumor. If this it true, then aspirin may have an anti-angiogenic effect. Another possibility is that the enzyme is associated with cell proliferation, which could encourage cancerous growth in certain circumstances. NSAIDS, then, would tend to counter this effect as well.
3) Cell Death - Aspirin and other NSAIDS may influence the cell's genetic "death blueprint" (called apoptosis) more directly.
The down side
On the surface, this may all sound almost too good to be true. Do most of us really have anti-cancer drugs in our bathrooms right now? Unfortunately, there is a well-known bugaboo about aspirin, ibuprofen, naproxen, and their buddies - stomach bleeding. It turns out that there are two COX enzymes, and COX-1 helps to create a protective effect on the lining of the GI tract. So while they inhibit inflammation, aspirin and the others also open the stomach to the ravages of acids and other harsh chemicals in our foods and bodies. Peptic ulcers, for example, kill 16,500 people per year in the U.S. Additionally, aspirin causes blood clotting problems (more bleeding) and other side effects.
There May Be An Alternative
There is a new category of anti-inflammatory drugs, which targets the COX-2 enzyme, but leaves COX-1 alone. The most well-known drugs in this group have the brand names of Celebrex and Vioxx. There has been promising research in the area of COX-2 inhibitors as chemopreventative agents, but there is still much to be learned. For one thing, there have been cases of severe bleeding associated with Celebrex as well (but not nearly so commonly as with other NSAIDS).
What about people who already have cancer? - This study specifically excluded women with ovarian cancer, and very little research has been done on this issue. Further, there is some evidence that aspirin may interfere with the actions of some chemotherapy drugs. However, if any of the anti-cancer mechanisms of NSAIDS turn out to be from anti-angiogenesis or apoptosis, there may be potential for future cancer treatment in this area.
For more information:
The Symptoms of Ovarian Cancer
The Facts of NSAIDS from About.com's Arthritis site has great information about the mechanisms of NSAIDS and their side effects.
Information about Celebrex from the US Food and Drug Administration.
Information
about angiogenesis and COX-2 inhibitors from Cancerpage.com
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Copyright © 2001 by Laura Dolson. All rights reserved. Please submit reprint requests to gyncancer@baymoon.com
The material on this page and Web site is for informational and educational purposes only, and should not substitute for medical advice. Anyone having questions about the application of information appearing here to a specific person or situation should obtain advice from a qualified physician.