Aspirin and colorectal cancer reviewed

This review analyzed recent research investigating the effects of aspirin on colorectal cancer outcomes.

Aspirin is a common anti-inflammatory drug often used to relieve pain and reduce fever. The anti-inflammatory properties of aspirin are associated with its ability to inhibit the actions of the enzyme cyclooxygenase-2 (COX-2). COX-2 is known to be involved in inflammatory processes, as well as in the growth of new blood vessels, both of which contribute to the development and spread of colorectal cancer. Previous studies have demonstrated that regular long-term use of aspirin significantly reduces the risk of developing colorectal cancer. However, whether initiation of aspirin treatment after the diagnosis of colorectal cancer could benefit patients is currently under debate.

The majority of studies reviewed demonstrated that aspirin use following cancer diagnosis is associated with significant benefit among colorectal cancer patients.

In a prospective study including 1,279 patients, regular use of aspirin (325 mg) after diagnosis was found to be associated with a 29% reduction in the risk of cancer-specific mortality among stage I-III colorectal cancer patients. The study demonstrated that among patients not receiving regular aspirin treatment before diagnosis, the risk of cancer specific mortality was reduced by 48% with aspirin use following diagnosis. A large retrospective study, including 4,481 colorectal cancer patients of any stage, demonstrated similar reductions in the risk of cancer-specific mortality with low-dose (80 mg) aspirin use. However, this reduced mortality risk was only found to be significant among colon cancer patients and not rectal cancer patients. Analysis of smaller trials also demonstrated a reduced risk of cancer recurrence after colorectal surgery among patients receiving aspirin following diagnosis.

Several studies investigated potential markers used to indicate which patients might benefit most from aspirin treatment following colorectal cancer diagnosis. The greatest reductions in mortality risk with aspirin use were seen among patients with tumors expressing high levels of COX-2, or with the common PIK3CA gene mutation.

This review concluded that aspirin use following colorectal cancer diagnosis may significantly improve patient outcomes, especially among colon cancer patients with PIK3CA mutation-positive tumors and those expressing high levels of COX-2.

Further randomized controlled studies are necessary to validate these results and determine the optimal duration and dosage of aspirin therapy following colorectal cancer diagnosis.

Consult with your physician regarding the risks and benefits of aspirin therapy in the management of colorectal cancer.