Two separate studies published in JAMA Oncology found that regular aspirin consumption may reduce the risks of ovarian cancer and hepatocellular carcinoma (HCC).
The cohort study pertaining to ovarian cancer evaluated data on women from the Nurses’ Health Study (NHS) (n = 93,664; mean age at baseline, 45.9 years), who were followed up from 1980 to 2014, and Nurses’ Health Study II (NHSII) (n = 111,834; mean age at baseline, 34.2 years), who were followed up from 1989 to 2015. Researchers compared aspirin use and nonaspirin nonsteroidal anti-inflammatory drug (NSAID) use, as well as use of neither medication.
Among the total women in both cohorts (n = 205,498), 1,054 had incident epithelial ovarian cancer. There were no differences between women taking aspirin and nonusers regardless of dose (hazard ratio [HR], 0.99; 95% CI, 0.83-1.19). When separating by low-dose (≤100-mg) and standard-dose (325-mg) aspirin, researchers observed an inverse association for reduced risk for low-dose aspirin (HR, 0.77; 95% CI, 0.61-0.96), but not standard-dose aspirin (HR, 1.17; 95% CI, 0.92-1.49). Significant positive trends were associated with duration of use (P = 0.02 for trend) and cumulative average tablets per week (P = 0.03 for trend).
The use of nonaspirin NSAIDs was correlated with a higher risk of ovarian cancer (HR, 1.19; 95% CI, 1.00-1.41), “although this finding requires confirmation,” the study authors wrote. They observed no clear link between acetaminophen use and ovarian cancer.
“What really differentiated this study from prior work was that we were able to analyze low-dose aspirin separately from standard dose aspirin,” said lead researcher Mollie Barnard, a postdoctoral fellow at Huntsman Cancer Institute at the University of Utah. “Our findings emphasize that research on aspirin use and cancer risk must consider aspirin dose. Our results also highlight the need for ongoing conversations between patients and their doctors on the risks and benefits of taking low-dose aspirin.”
For the HCC study, which was separate from the ovarian cancer research, researchers evaluated data from the NHS and the Health Professionals Follow-up Study between Nov. 1, 2017, and March 1, 2018. There were 133,371 participants in total (87,507 women and 45,864 men). They self-reported aspirin use, frequency, dosage, and duration of use since 1980 in women and 1986 in men. Mean age at median follow-up was 62 and 64 years old for women and men, respectively.
During the study period, there were 108 incident HCC cases (65 women, 43 men). Regular aspirin use ( ≥ 2 standard-dose [325-mg] tablets per week) significantly reduced HCC risk when compared with nonregular use (adjusted HR, 0.51; 95% CI, 0.34-0.77). Higher doses correlated with decreased HCC risk. Measuring against nonuse, the multivariable-adjusted HR for HCC was 0.87 (95% CI, 0.51-1.48) for up to 1.5 standard-dose tablets per week, 0.51 (95% CI, 0.30-0.86) for more than 1.5 to 5 tablets per week, and 0.49 (95% CI, 0.28-0.96) for more than 5 tablets per week (P = 0.0006 for trend). Participants who took at least one 1.5 weekly standard-dose tablet for five years or longer had an adjusted HCC HR of 0.41 (95% CI, 0.21-0.77). Nonaspirin NSAID use showed no association with HCC risk (adjusted HR, 1.09; 95% CI, 0.78-1.51).
“The long duration of aspirin use could be necessary because primary liver cancer takes many years to grow. Aspirin may act at the earliest stages of cancer development, or even at precancerous stages, by delaying or preventing inflammation or liver fibrosis,” said study author Tracey Simon, MD, a research fellow in the Massachusetts General Hospital Division of Gastroenterology. “While it’s still too early know whether starting aspirin therapy might be an effective strategy to prevent HCC, efforts to understand the mechanisms behind these beneficial effects could help identify urgently-needed prevention strategies or biomarkers for a cancer that is a growing public health problem.”
Simon said potential risk factors warrant further research.
“Since regular aspirin use carries the risk of increased bleeding, the next step should be to study its impact in populations with established liver disease, since that group is already at risk for primary liver cancer.”