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12-02-2016 | Epidemiology | Article

Aspirin and colorectal cancer: the promise of precision chemoprevention

Authors: David A. Drew, Yin Cao, Andrew T. Chan

Abstract

Aspirin (acetylsalicylic acid) has become one of the most commonly used drugs, given its role as an analgesic, antipyretic and agent for cardiovascular prophylaxis. Several decades of research have provided considerable evidence demonstrating its potential for the prevention of cancer, particularly colorectal cancer. Broader clinical recommendations for aspirin-based chemoprevention strategies have recently been established; however, given the known hazards of long-term aspirin use, larger-scale adoption of an aspirin chemoprevention strategy is likely to require improved identification of individuals for whom the protective benefits outweigh the harms. Such a precision medicine approach may emerge through further clarification of aspirin's mechanism of action.

Nat Rev Cancer 2016; 16: 173–186. doi:10.1038/nrc.2016.4

Subject terms: Cancer genomics • Cancer prevention • Colorectal cancer

Despite greater adoption of population screening and considerable advances in understanding the molecular basis of colorectal neoplasia, colorectal cancer (CRC) remains the second leading cause of cancer deaths in the United States, with an estimated 129,700 new cases expected for 2015 (Ref. 1). Aspirin (acetylsalicylic acid) has emerged as perhaps the most promising agent for the chemoprevention of CRC2, 3. This is due in large part to remarkably consistent data that have emerged from numerous basic, clinical and epidemiological studies over the past several decades (Fig. 1). The United States Preventive Services Task Force (USPSTF) originally recommended against the use of aspirin for the prevention of CRC in 2007 (Ref. 4). However, in 2015, in their updated draft recommendations5 for low-dose aspirin in the primary prevention of cardiovascular disease (CVD), the USPSTF acknowledged that supporting evidence had become so compelling that CRC prevention warranted inclusion in their rationale for routine aspirin use among those aged between 50 and 69 with specific cardiovascular risk profiles6, 7 (Box 1). This decision distinguishes aspirin as the first pharmacological agent to be endorsed for cancer chemoprevention in a population not characterized as having a high risk of developing cancer. Nevertheless, the USPSTF also cautioned against the potential harms associated with regular aspirin use and highlighted the need to clarify the mechanisms by which aspirin prevents the development of colorectal neoplasia.

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