Regular aspirin use may reduce GI cancer risk
Regular use of aspirin may reduce the risk of gastrointestinal cancers, according to two studies presented at DDW 2020.
In the first study, researchers used data from the Prostate, Lung, Colorectal, and Ovarian (PLCO) Cancer Screening Trial to identify 146,152 individuals aged ≥65 years who were enrolled in the database between 1993 and 2001 and had data on aspirin use. Individuals with a history of cancer or cancer treatment (except basal or squamous cell carcinoma of the skin) were excluded.
Use of aspirin ≥3 times per week was associated with a reduced risk of gastrointestinal cancer (hazard ratio [HR], 0.75, 95 percent confidence interval [CI], 0.66–0.84) and colorectal cancer-specific (HR, 0.71, 95 percent CI, 0.61–0.84) mortality. [DDW 2020, abstract 388 – 2020]
Stratification of the findings suggested the influence of body mass index (BMI), with the reduced risk of gastrointestinal cancer and CRC mortality specific to patients with BMI 25.0–29.9 kg/m2 who used aspirin ≥3 times per week.
Consistent use of aspirin (eg, ≥1 time per week at baseline and follow-up) was also associated with a reduced risk of gastrointestinal cancer (HR 0.75, 95 percent CI, 0.59–0.94) and CRC (HR 0.62, 95 percent CI, 0.46–0.85) mortality.
Prior research has demonstrated a link between systemic inflammation and poor prognosis in CRC. [Clin Colorectal Cancer 2017;16:264-274; World J Gastroenterol 2019;25:4383‐4404] In line with this, researchers have examined the impact of aspirin and other non-steroidal anti-inflammatory drugs (NSAIDs) to prevent CRC. [Best Pract Res Clin Gastroenterol 2011;25:461‐472; Genes Environ 2016;38:6] In addition, recent research has also linked obesity to an increased risk of cancer. [EBioMedicine 2018;30:14‐28]
“The results of this study suggest a beneficial effect of aspirin use in reducing the risk of gastrointestinal cancer and CRC mortality,” said the researchers, noting that the effect may be influenced by BMI.
“Despite recent evidence suggesting increased cancer-specific mortality among aspirin users, the data from this large trial does not support that conclusion and further validates previously conducted epidemiological and randomized controlled trials investigating aspirin use,” they said.
The second study comprised 159,133 individuals from the Nurses’ Health Study (NHS) and the Health Professionals Follow-up Study (HPFS). Of these, 327 individuals (187 women and 140 men) were diagnosed with gastric adenocarcinoma over a 30-year follow-up period.
After adjustment*, women who used aspirin ≥2 times per week (regular users) had a significantly lower risk of gastric adenocarcinoma than nonregular users (adjusted [adj]HR, 0.43, 95 percent CI, 0.30–0.62). Conversely, regular use of aspirin did not reduce gastric adenocarcinoma risk in men (adjHR, 1.13, 95 percent CI, 0.80–1.59; pheterogeneity<0.001). [DDW 2020, abstract 391 – 2020]
Furthermore, the reduced risk of gastric adenocarcinoma in women only applied to long-term aspirin use (>10 years; HR, 0.39, 95 percent CI, 0.25–0.60) and was greater with increasing aspirin dose (ie, adjHR, 0.61 [0.5–1.5 tablets/week], adjHR, 0.53 [1.5–5 tablets/week], and adjHR, 0.40 [>5 tablets/week]; ptrend=0.002) compared with <0.5 standard (325-mg) tablets per week.
“Regular, long-term aspirin use was associated with a reduced risk of gastric adenocarcinoma among women, but not men [and] the benefit appeared after at least 10 years of use and was maximized at doses greater than five standard tablets per week,” said the researchers. “Further studies are needed to investigate a potential sex difference in the association of aspirin use with risk of gastric adenocarcinoma,” they said.