Abstract

MARTINS, Sílvia Colmonero; CARDOSO, Sofia  and  MARQUES, Ana Raquel. What is the role of aspirin in primary prevention of colorectal cancer in medium-risk individuals?: An evidence-based review. Rev Port Med Geral Fam [online]. 2019, vol.35, n.1, pp.42-51. ISSN 2182-5173.  https://doi.org/10.32385/rpmgf.v35i1.12147.

Introduction: Colorectal cancer (CRC) is the second leading cause of cancer-related mortality in developed countries. Primary prevention is bases on lifestyle changes, and chemoprophylaxis with aspirin® is currently under investigation. Some studies have shown benefit of aspirin® in the prevention of CRC. Objective: To determine the evidence the effect of aspirin® on CRC incidence and mortality in medium-risk adult subjects. Methods: Randomised controlled trials, meta-analyses, systematic reviews, evidence based guidelines, as well as Portuguese primary care journals and electronic databases, including MEDLINE and Cochrane Library, were searched. Searches were limited to publications between 1/4/2006 and 1/4/2016, in Portuguese, English or Spanish and used the MeSH terms: ‘Aspirin’, ‘Primary prevention’, and ‘Colorectal neoplasms’. The Strength of Recommendation Taxonomy (SORT) of the American Academy of Family Physicians was used to rate the strength of a recommendation and the levels of evidence. Results: Seventy-five papers were obtained, amongst which seven met the inclusion criteria: one evidence-based guideline, one meta-analysis, three systematic reviews, one cohort study, and one original study. The guideline does not recommend aspirin® for CRC prevention in medium risk individuals (SORT B). Overall, the studies seem to show that aspirin®, when administrated for = 5 years at a dose = 300mg/day, may reduce the incidence of CRC, with a more pronounced effect 10 years after starting treatment. Lower doses given less frequently or shorter treatment duration appear to be less effective. Conclusions: When regularly administrated, aspirin® may reduce the incidence of CRC, with a possible impact on CRC mortality (SORT B). However, the use of aspirin® should be recommended with caution because of the increased incidence of adverse, such as gastrointestinal bleeding. Further RCTs are needed to clarify which dose and duration provide the maximum cancer benefit and minimal haemorrhagic risk.

Keywords : Aspirin; Primary prevention; Colorectal neoplasms.

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