Aspirin, cyclooxygenase inhibition and colorectal cancer

Abstract

Colorectal cancer (CRC) is the third most common type of cancer worldwide. Screening measures are far from adequate and not widely available in resourcepoor settings. Primary prevention strategies therefore remain necessary to reduce the risk of developing CRC. Increasing evidence from epidemiological studies, randomized clinical trials and basic science supports the effectiveness of aspirin, as well as other non-steroidal anti-inflammatory drugs, for chemoprevention of several types of cancer, including CRC. This includes the prevention of adenoma recurrence and reduction of CRC incidence and mortality. The detectable benefit of daily low-dose aspirin (at least 75 mg), as used to prevent cardiovascular disease events, strongly suggests that its antiplatelet action is central to explaining its antitumor efficacy. Daily low-dose aspirin achieves complete and persistent inhibition of cyclooxygenase (COX)-1 in platelets (in pre-systemic circulation) while causing a limited and rapidly reversible inhibitory effect on COX-2 and/or COX-1 expressed in nucleated cells. Aspirin has a short half-life in human circulation (about 20 minutes); nucleated cells have the ability to resynthesize acetylated COX isozymes within a few hours, while platelets do not. COX-independent mechanisms of aspirin have been suggested to explain its chemopreventive effects but this concept remains to be demonstrated in vivo at clinical doses.© 2014 Baishideng Publishing Group Co., Limited. All rights reserved.Key words: Aspirin; Colorectal cancer; Cyclooxygenase inhibition; Mechanisms; Risk; Benefits Core tip: Colorectal cancer (CRC) is a major cause of morbidity and mortality worldwide. Currently, CRC screening programs are not widely available and need to be improved. New prevention strategies are therefore necessary. Daily low-dose aspirin, as given for the prevention of cardiovascular disease events, has demonstrated benefits in clinical and basic studies in terms of preventing adenoma recurrence and decreasing the incidence of CRC and attributable mortality. These findings indicate that the antiplatelet action of aspirin plays a central role in its antitumor effect. Cyclooxygenasedependent and independent mechanisms have been suggested to explain this effect. Extensive translational medical research is mandatory for future progress in CRC prevention.Sostres C, Gargallo CJ, Lanas A. Aspirin, cyclooxygenase inhibition and colorectal cancer.

Nonviral Oncogenic Antigens and the Inflammatory Signals Driving Early Cancer Development as Targets for Cancer Immunoprevention

“…Aspirin belongs to the class of non-steroidal anti-inflammatory drugs (NSAIDs) that irreversibly inactivates cycooxygenase (COX) 1 and 2 to prevent the synthesis of prostanoids, including prostaglandins, prostacyclin, and thromboxane A (29, 39, 40). Aspirin's inhibition of these metabolites produces its analgesic, antipyretic, anti-inflammatory, and cardiovascular effects (39, 40).…”

“…Aspirin's inhibition of these metabolites produces its analgesic, antipyretic, anti-inflammatory, and cardiovascular effects (39, 40). Several clinical studies have shown that a safe daily low-dose of aspirin, taken for the prevention of cardiovascular disease, also decreases the incidence and recurrence of colorectal cancer (39, 40).…”

“…Aspirin's inhibition of these metabolites produces its analgesic, antipyretic, anti-inflammatory, and cardiovascular effects (39, 40). Several clinical studies have shown that a safe daily low-dose of aspirin, taken for the prevention of cardiovascular disease, also decreases the incidence and recurrence of colorectal cancer (39, 40). Additionally, meta-analysis of cardiovascular trials revealed that a daily low-dose of aspirin may reduce cancer incidence and cancer mortality from all cancers combined (39, 40).…”

“…Several clinical studies have shown that a safe daily low-dose of aspirin, taken for the prevention of cardiovascular disease, also decreases the incidence and recurrence of colorectal cancer (39, 40). Additionally, meta-analysis of cardiovascular trials revealed that a daily low-dose of aspirin may reduce cancer incidence and cancer mortality from all cancers combined (39, 40). Aspirin's chemopreventive effects result from its modulation of inflammatory signaling pathways that regulate the TME.…”

UCA1, a long noncoding RNA, promotes the proliferation of CRC cells via p53/p21 signaling

“…Colorectal cancer (CRC) is one of the most common types of human tumor malignancies the worldwide, affecting more than one million individuals every year [1]. Despite recent advances in surgical resection, radiotherapy, and chemotherapy have improved clinical outcomes for patients, it remains the third leading cause of cancerrelated death in the United States in both males and females [2].…”