There is growing interest in the potential role of aspirin in reducing the risk of cancer or improving survival after diagnosis, though observational studies demonstrate mixed results.
An analysis of 135,965 men and women from the Nurses’ Health Study and Health Professionals Follow-up Study, found, for example, a significant decrease in risk for overall cancer with regular aspirin use (relative risk [RR], 0.97; 95% CI, 0.94-0.99), which was defined as 0.5 to 1.5 standard tablets per week for at least 6 years.1 The drivers of this association were gastrointestinal tract and colorectal cancers.
Aspirin use and cancer has primarily been evaluated by observational studies, which may have substantial bias. Several randomized controlled trials, however, are ongoing, including ASPIRED (Clinicaltrials.gov Identifier: NCT02394769) and ADD-ASPIRIN (ClinicalTrials.gov Identifier: NCT02804815).2,3
The following is a set of recent trials on the relationship between aspirin use and cancer and their findings.
The United States Preventative Services Task Force (USPSTF) has published recommendations on aspirin use for the reduction of risk of colorectal cancer (CRC). According to their recommendation, the risk reduction occurs after 5 to 10 years of use and is therefore suggested for use among patients age 50 to 59. Though a dose for CRC risk reduction is not specified, the USPSTF recommends 81 mg for cardiovascular disease risk reduction.4
The USPSTF recommendations are based on a systematic review demonstrating that at least 75 mg of aspirin daily or every other day significantly reduced the risk of all-cause mortality in 10 years (RR, 0.94; 95% CI, 0.89-0.99) and reduced the risk of CRC mortality by 33% during over a 20-year period. The incidence of CRC was reduced by 40% after 10 years of use (RR, 0.60; 95% CI, 0.47-0.76). 5
An observational study demonstrated significantly improved overall survival (OS; hazard ratio [HR], 0.41; 95% CI, 0.37-0.47) with aspirin, but not other thrombocyte aggregation inhibitors, among patients with CRC.6
A meta-analysis of observational studies found that post-diagnosis aspirin use was significantly associated with improved OS with CRC (HR, 0.78; 95% CI, 0.64-0.96), but not CRC-specific mortality or pre-diagnosis aspirin use.7
Other Gastrointestinal/Endocrine Cancers
An observational study demonstrated significantly improved survival among aspirin users with esophageal, hepatobiliary, and CRC (HR, 0.52; 95% CI, 0.44-0.63).8
Another observational study from the same database demonstrated significantly improved OS among aspirin users with esophageal cancer (adjusted RR, 0.42; 95% CI, 0.30-0.57; P <.001).9
A meta-analysis of observational studies found that post-diagnosis aspirin use was significantly associated with improved OS with rectal cancer (HR, 0.90; 95% CI, 0.50-0.85).7
A case-control study of 761 patients with pancreatic cancer and 794 controls found that ever-regular aspirin use decreased the risk of pancreatic cancer (odds ratio [OR], 0.54; 95% CI, 0.40-0.73; P = 10-4.2) by about 8% for each cumulative year of use (OR, 0.92; 95% CI, 0.87-0.97; P =.0034).10
An observational study of 15,140 patients with newly diagnosed breast cancer found no association between post-diagnosis use and disease-specific mortality, even with increasing duration of use.11
A meta-analysis of 13 prospective cohort studies that included 857,831 patients did not find a significant reduction in risk of breast cancer with aspirin use (RR, 0.94; 95% CI, 0.87-1.01; P =.051).12
Another meta-analysis of 8 cohort studies and 2 nested case-control studies that included 26,931 subjects with post-diagnosis aspirin use and 673,453 with pre-diagnosis use demonstrated that post-diagnosis use decreased breast cancer–specific mortality (RR, 0.73; 95% CI, 0.54-0.98; P =.04), but not all-cause mortality.13
A small, prospective, observational study of 313 patients with small-cell lung cancer found no association between aspirin use and survival or metastasis.14
A meta-analysis of 18 observational studies that included 19,835 patients similarly found no overall association between aspirin use and incidence of lung cancer, though 2 case-control studies with heterogeneity demonstrated a significantly decreased risk of disease (OR, 0.71; 95% CI, 0.56-0.91).15
A prospective cohort study of 22,071 men from the Physicians’ Health Study (ClinicalTrials.gov Identifier: NCT00000500) demonstrated that the risk of lethal prostate cancer was reduced with regular current (HR, 0.68; 95% CI, 0.52-0.89) or past aspirin use (HR, 0.54; 95% CI, 0.40-0.74). Among men with nonlethal prostate cancer, current post-diagnosis aspirin use reduced the risk of developing lethal disease (HR, 0.68; 95% CI, 0.52-0.90) and overall mortality (HR, 0.72; 95% CI, 0.61-0.90).16
A meta-analysis of 24 observational studies demonstrated that regular aspirin use significantly reduced OS (RR, 0.86; 95% CI, 0.81-0.92) and prostate cancer–specific mortality (RR, 0.83; 95% CI, 0.75-0.91), particularly with longer duration of use.17
A case-control study of 823 and 1034 men with and without prostate cancer, respectively, demonstrated that daily use of aspirin for over 3 years significantly reduced the risk of advanced prostate cancer (T3: OR, 0.35; 95% CI, 0.17-0.73; T4: OR, 0.22; 95% CI, 0.08-0.60) and disease recurrence among African American men.18
A meta-analysis of 5 observational studies including 332,660 adults found no association between aspirin use and the risk of multiple myeloma (MM).19
A prospective analysis of the Health Professionals Follow-up Study and Nurses’ Health Study that included 2,395,458 person-years demonstrated that regular use (at least 5 times per week) of 325 mg of aspirin significantly reduced risk of MM by 39% (HR, 0.61; 95% CI, 0.39-0.94). Continuous regular use of 11 years or longer was also associated with lower risk of MM (HR, 0.63; 95% CI, 0.41-0.95).20
- Cao Y, Nishihara R, Wu K, et al. The population impact of long-term use of aspirin and risk of cancer. JAMA Oncol. 2016;2:762-769.
- Drew DA, Chin SM, Gilpin KK, et al. Aspirin intervention for the reduction of colorectal cancer risk (ASPIRED): a study protocol for a randomized controlled trial. Trials. 2017;18:50.
- Coyle C, Cafferty FH, Rowley S, et al; Add-Aspirin Investigators. ADD-ASPIRIN: a phase III, double-blind, placebo controlled, randomised trial assessing the effects of aspirin on disease recurrence and survival after primary therapy in common non-metastatic solid tumours. Contemp Clin Trials. 2016;51:56-64.
- Bibbins-Domingo K; U.S. Preventative Services Task Force. Aspirin use for the primary prevention of cardiovascular disease and colorectal cancer: U.S. Preventative Services Task Force Recommendation Statement. Ann Intern Med. 2016;164:836-45.
- Chubak J, Kamineni A, Buist DS, Anderson ML, Whitlock EP. Aspirin use for the prevention of colorectal cancer: an updated systematic evidence review for the U.S. Preventive Services Task Force [internet]. Rockville (MD): Agency for Healthcare Research and Quality (US); 2015. Report No.: 15-05228-EF-1.
- Frouws MA, Rademaker E, Bastiaannet E, et al. The difference in association between aspirin use and other thrombocyte aggregation inhibitors and survival in patients with colorectal cancer. Eur J Cancer. 2017;77:24-30.
- Li P, Wu H, Zhang H, et al. Aspirin use after diagnosis but not pre-diagnosis improves established colorectal cancer survival: a meta-analysis. Gut. 2015;64:1419-25.
- Frouws MA, Bastiaannet E, Langley RE, et al. Effect of low-dose aspirin use on survival of patients with gastrointestinal malignancies: an observational study. Br J Cancer. 2017;116:405-13.
- van Staalduinen J, Frouws M, Reimers M, et al. The effect of aspirin and nonsteroidal anti-inflammatory drug use after diagnosis on survival of oesophageal cancer patients. Br J Cancer. 2016;114:1053-59.
- Risch HA, Lu L, Streicher SA, et al. Aspirin use and reduced risk of pancreatic cancer. Cancer Epidemiol Biomarkers Prev. 2017;26:68-74.
- Mc Menamin UC, Cardwell CR, Hughes CM, Murray LJ. Low-dose aspirin use and survival in breast cancer patients: a nationwide cohort study. Cancer Epidemiol. 2017;47:20-7.
- Lu L, Shi L, Zeng J, Wen Z. Aspirin as a potential modality for the chemoprevention of breast cancer: a dose-response meta-analysis of cohort studies from 857,831 participants.. Oncotarget. 2017 Mar 17. doi: 10.18632/oncotarget.16315 [Epub ahead of print]
- Zhong S, Zhang X, Chen L, Ma T, Tang J, Zhao J. Association between aspirin use and mortality in breast cancer patients: a meta-analysis of observational studies. Breast Cancer Res Tret. 2015;150:199-207.
- Maddison P. Effects of aspirin on small-cell lung cancer mortality and metastatic presentation. Lung Cancer. 2017;106:67-9.
- Jiang HY, Huang TB, Xu L, et al. Aspirin use and lung cancer risk: a possible relationship? Evidence from an updated meta-analysis. PLoS ONE. 2015;10:e0122962.
- Downer MK, Allard CB, Preston MA, et al. Regular aspirin use and the risk of lethal prostate cancer in the Physicians’ Health Study. Eur Urol. 2017 Feb 8. doi: 10.1016/j.eururo.2017.01.044 [Epub ahead of print]
- Huang TB, Yan Y, Guo ZF, et al. Aspirin use and the risk of prostate cancer: a meta-analysis of 24 epidemiologic studies. Int Urol Nephrol. 2014;46:1715-28.
- Smith CJ, Dorsey TH, Tan W, Jordan SV, Loffredo CA, Ambs S. Aspirin use reduces the risk of aggressive prostate cancer and disease recurrence in African-American men. Cancer Epidemiol Biomarkers Prev. 2017 Mar 14. doi: 10.1158/1055-9965.EPI-16-1027 [Epub ahead of print]
- Lee SF, Ng TY, Wong FC, Tung SY. Aspirin and risk of multiple myeloma in adults: a systematic review and meta-analysis. Leukemia Res Rep. 2017;7:23-8.
- Birmann BM, Giovannucci E, Rosner B, Colditz GA. Regular aspirin use and risk of multiple myeloma: a prospective analysis in the Health Professionals Follow-up Study and Nurses’ Health Study. Cancer Prev Res (Phila). 2014;7:33-41.
This article originally appeared on Cancer Therapy Advisor