Long-Term Aspirin Use Before Diagnosis May Reduce Risk of Death From Colorectal Cancer

Long-term regular aspirin use before a diagnosis of colorectal cancer (CRC) is associated with a lower risk of CRC-specific mortality, according to a study published in the Journal of the National Cancer Institute.

The study authors noted that long-term aspirin use has been shown to reduce the incidence of CRC, but there is no evidence on aspirin use and mortality outcomes in CRC patients. 

With that in mind, the researchers prospectively analyzed patients from the Cancer Prevention Study-II Nutrition Cohort who were cancer-free at baseline in 1992 or 1993 and were diagnosed with CRC during follow-up through 2015.

The researchers looked at pre- and postdiagnosis use of aspirin. The prediagnosis cohort included 2686 participants, and the postdiagnosis cohort included 1931 participants.

Patients reported information on aspirin use via questionnaires given at baseline, in 1997, and every 2 years thereafter. Regular aspirin use was defined as taking 15 or more pills per month.

Patients were considered short-term aspirin users if they reported regular aspirin use on the prediagnosis questionnaire only (submitted a mean of 1.5 years before CRC diagnosis). Patients were considered long-term aspirin users if they reported regular aspirin use on the prediagnosis questionnaire and the prior questionnaire.

Results showed that long-term regular aspirin use before CRC diagnosis was significantly associated with a lower risk of CRC-specific mortality, when compared with no aspirin use before diagnosis (multivariable-adjusted hazard ratio [HR], 0.69; 95% CI, 0.52-0.92).

Regular aspirin use postdiagnosis was not significantly associated with a lower risk of CRC-specific mortality, when compared with no aspirin use postdiagnosis (HR, 0.82; 95% CI, 0.62-1.09).

However, patients who began taking aspirin regularly after diagnosis had a lower risk of CRC-specific mortality, when compared with patients who did not use aspirin during the pre- and postdiagnosis periods (HR, 0.60; 95% CI, 0.36-0.98).

In addition, long-term regular aspirin use before CRC diagnosis was associated with lower odds of being diagnosed with distant metastases, when compared with no aspirin use before diagnosis (multivariable-adjusted odds ratio, 0.73; 95% CI, 0.53-0.99).

The researchers also looked at the use of non-aspirin non-steroidal anti-inflammatory drugs (NSAIDs) but found no significant associations with non-aspirin NSAIDs and CRC outcomes.

“Collectively, these results point toward a novel and potentially important model through which aspirin may prevent distant metastases at the time of diagnosis with colon or rectal cancer,” the study authors wrote. “This finding is particularly important because treatment options are usually quite good for localized and regional disease, whereas those options have limited success for patients diagnosed with distant metastases.”

Disclosures: This research was supported by the American Cancer Society. One study author declared an affiliation with FAKnostics, LLC. Please see the original reference for a full list of disclosures.

Reference

Figueiredo JC, Jacobs EJ, Newton CC, et al. Associations of aspirin and non-aspirin non-steroidal anti-inflammatory drugs with colorectal cancer mortality after diagnosis. J Natl Cancer Inst. 2021;113(7):833-840. doi:10.1093/jnci/djab008