Aspirin, one of the most common over the counter drugs, generally taken for pain, fever or inflammation, seems to have another potential use – the prevention of colorectal cancer (CRC).
Acetylsalicylic acid (ASA) or simply aspirin is a nonsteroidal anti-inflammatory drug (NSAID) and works by inhibiting the enzyme cyclooxygenase-1 (COX-1) responsible for the production of prostanoids, mainly thromboxane and prostaglandins. This, in turn, affects the formation of prostaglandin-endoperoxide synthase 2 (PTGS2 of COX2) an agent associated with a number of types of cancer.
While the exact mechanism through which ASA acts to prevent colorectal cancer is still unknown, it seems that by disrupting phosphatidylinositol 3-kinase (PI3K) signaling, there is a reduction in cell proliferation, tumor angiogenesis and reduced immune surveillance of cancer cells.
There are a number of studies currently available, each using different methods and doses, showing reductions in incidence anywhere between 15% and 40%. It seems that the longer the treatment period with higher doses, the more noticeable the results are, but also more pronounced side effects.
A review by Catherine Dubé and associate doctors, found reductions between 13% and 28% with doses ranging from 81 mg to 325 mg per day, though the beneficial effects only started to appear after one year of treatment.
Another study conducted by Flossmann and colleagues showed a 36% reduction of CRC incidence for patients who had been administered 300mg daily doses for at least 5 years. Even so, the positive benefits became observable after 10 years.
While the results look very promising, it is important to note that research is still underway and this path of medication is not yet approved by the FDA for the general public.