Statins more protective than aspirin against PDAC risks
Statin use, particularly in smokers, obese patients and nondiabetics, has a strong and dose-dependent association with decreasing risk of pancreatic ductal adenocarcinoma (PDAC), according to a new study.
In contrast, there is no solid evidence to support the synergistic and chemopreventive effects of statins in combination with aspirin.
“This is the first study evaluating the possible association between overall, exclusive and combined use of both aspirin and statins and PDAC risk at the same time,” researchers said.
The study included 408 incident PDAC patients (mean age 68.1±11.6 years; 51.2 percent male) matched 1:2 for age and sex with 816 healthy controls (mean age 67.9±11.9 years; 51.2 percent male).
The ever use of aspirin, reported in 19.1 percent (n=78) of cases and 23.4 percent (n=191) of controls, was associated with a decrease in PDAC risk that almost reached significance after adjusting for age and sex (odds ratio [OR], 0.74; 95 percent CI, 0.54 to 1.02; p=0.06). [Sci Rep 2017;7:13024]
However, additional adjustments for other covariates like body mass index, familial history of pancreatic cancer, smoking and drinking, among others, attenuated this significant relationship (adjusted OR, 0.77; 0.53 to 1.11; p=0.16).
On the other hand, ever use of statin was reported in 18.1 percent (n=74) of cases and 24.9 percent (n=203) of controls and was associated with a strong and significant decrease in PDAC risk after adjusting for age and sex (OR, 0.64; 0.48 to 0.88; p=0.005).
As opposed to aspirins, statin use did not lose its significant protective effect against PDAC risk when multivariable analysis was performed, controlling for the above covariates (adjusted OR, 0.61; 0.43 to 0.88; p=0.007).
Consistent with previously published reports, the present study found that “PDAC risk is inversely associated with the overall statin use, with a dosage-dependent effect,” though the mechanism and underlying reasons for which, particularly the enhanced protective effect of statins on certain subgroups, are still unknown.
Another covariate-adjusted multivariable analysis showed that exclusive statin use (adjusted OR, 0.51; 0.32 to 0.80; p=0.004), but not exclusive aspirin use (adjusted OR, 0.64; 0.40 to 1.01; p=0.06), was significantly associated with lower PDAC risks.
Notably, combined use of aspirin and statins did not substantially change the protective effect against PDAC risk compared with use of statins alone (OR, 0.54; 0.34 to 0.87; p=0.01), suggesting the absence of a synergistic effect between the two medications, said researchers.
“Both exclusive aspirin and statin use were related to a reduced PDAC risk, with statin use showing a risk reduction of 49 percent, higher than that of aspirin, which was only borderline statistically significant,” the researchers noted.
“[T]herefore, we might speculate that the main protective effect of the combined use is due to statins,” they added.