Originally published 2/28/2021
A 2024 analysis involved 20 years’ worth of data on nearly a million people ages 40-70 who were followed for an average of 18.2 years. Out of the 909,531 individuals, 422,778 developed cancers during the study period. Associations were established for any aspirin use (low-dose to high-dose), taking into consideration continuity, duration and cumulative amount.
As with the 2021 PLCO study reported below, there were mixed results. The authors of the 2024 paper write that “… long-term (≥5 or ≥10 years) use was associated with at least 10% reductions in hazard ratios for several cancer sites: colon, rectum, esophagus, stomach, liver, pancreas, small intestine, head and neck, brain tumors, meningioma, melanoma, thyroid, non-Hodgkin lymphoma, and leukemia. Substantiated elevated hazard ratios were found for lung and bladder cancer.” However, “… consistent high-dose aspirin use was associated with reduced hazard ratios for cancer overall.”[i]
The results of the 2024 paper are somewhat inconsistent with its 2021 predecessor but on balance, aspirin seems to offer far more benefits than downsides.
Aspirin is a humble drug. Aspirin tablets have been on shelves in drugstores, grocery stores, airport shops, quickmarts and many other outlets since 1915. In addition to pain relief, its benefits include reducing the risk of heart attack and stroke by reducing the production of hormones that can lead to the blood clots that are often responsible for these catastrophic events.
Today, non-aspirin pain relievers like Tylenol, Aleve, etc. are more likely to be go-to remedies for aches and other discomforts. However, 80% of people with heart disease rely on aspirin as a preventative, and it’s estimated that at least 1/3 of all adults use aspirin regularly.
Aspirin and cancer
Within the last 30 years, attention has been drawn to the relationship between aspirin use, cancer development, and cancer survival. I have posted several blogs on this topic, the most recent of which reported on prevention of colorectal and other gastrointestinal cancers.
Now, at the kickoff of the 2021 New Year, JAMA has published a thorough analysis of data gathered by the Prostate, Lung, Colorectal and Ovarian (PLCO) Cancer Screening Trial, which recruited cancer free adults ages 55-74 from 1993-2001, with extended follow-up. Data for the current analysis was comprised of 139,896 individuals (median age at baseline 66.4 years).[ii]
The stated objective of the study was to “… investigate the association of aspirin use with risk of developing new cancers and site-specific cancer-associated survival in bladder, breast, esophageal, gastric, pancreatic, and uterine cancers.” Thus, they were examining the relationship between the occurrence and mortality rates of these six cancers and the use of aspirin. They sorted the data according to those who used aspirin at least 3x/week, and those who had any aspirin use (even occasional). Among the background observations they note that among the four cancers screened as part of the original trial design, aspirin use has been linked with lower risk of colorectal polyps and colorectal cancer, whereas the PLCO study found “…modest to no association between aspirin use and prostate and ovarian incidence and survival.” (On the other hand, a large 2014 study found that high-risk prostate cancer patients who used aspirin after diagnosis had significantly less chance of dying from their prostate cancer than those who did not use aspirin.)
Results of new PCLO analysis
To return to the current published analysis, the research team was hypothesizing that aspirin use would reduce the incidence of new cancers, and would lower the rates of cancer-specific death. Regarding the first part, the outcome might be disappointing. Among the six types of cancers studied, there was no association between their incidence (new diagnoses) and aspirin use. However, “…aspirin use at least 3 times/week was associated with increased survival among patients with bladder and breast cancers but not among those with esophageal, gastric, pancreatic, or uterine cancer. A similar association of any aspirin use with bladder and breast cancer survival was observed. (Emphasis mine)
While this was a very large and extensive study, research into aspirin and cancer continues. The Loomans-Kropp paper is a population study, meaning the statistics are based on previous records that include patient questionnaires and clinical data from the periodic cancer screenings (prostate, lung, colorectal, ovarian) that were part of the study protocol, as well as other cancers that were diagnosed during the study period.
Results from other studies may vary from this population study. For example, two studies that specifically compared aspirin use vs. non-use among prostate cancer patients who were treated with either surgery or radiation, risk of recurrence or metastasis was lower among those who used aspirin.
I believe aspirin, used by the ancient Egyptians and Greeks in a form derived from willow bark, is one of Nature’s gifts. It’s possible that as research continues, we’ll find even more benefits from this humble substance. As UCLA cardiologist Dr. Karol Watson put it, “If I’m stranded on a desert island, and I can take one drug with me, that’s the one I’m taking.”[iii] Perhaps we can apply a famous advertising slogan, “Don’t leave home without it.”
NOTE: This content is solely for purposes of information and does not substitute for diagnostic or medical advice. Talk to your doctor if you are experiencing pelvic pain, or have any other health concerns or questions of a personal medical nature.
[i] Skriver C, Maltesen T, Dehlendorff C, Skovlund CW et al. Long-term aspirin use and cancer risk: a 20-year cohort study. J Natl Cancer Inst. 2024 Apr 5;116(4):530-538.
[ii] Loomans-Kropp HA, Pinsky P, Umar A. Evaluation of Aspirin Use With Cancer Incidence and Survival Among Older Adults in the Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial. JAMA Netw Open. 2021 Jan 4;4(1):e2032072.
[iii] https://www.cnn.com/2010/HEALTH/12/22/aspirin.history/index.html
About Dr. Dan Sperling
Dan Sperling, MD, DABR, is a board certified radiologist who is globally recognized as a leader in multiparametric MRI for the detection and diagnosis of a range of disease conditions. As Medical Director of the Sperling Prostate Center, Sperling Medical Group and Sperling Neurosurgery Associates, he and his team are on the leading edge of significant change in medical practice. He is the co-author of the new patient book Redefining Prostate Cancer, and is a contributing author on over 25 published studies. For more information, contact the Sperling Prostate Center.
