Letter to the Editor: Is Aspirin a Drug or Just a Marker for Biliary Cancer?

The research by Liao et al.(1) showed that postdiagnosis aspirin use improved the mortality of various subtypes of biliary tract cancer (BTC). The results were impressive, with the adjusted hazard ratios of mortality ranging from 0.51 to 0.58, and all subgroup analyses were statistically significant. However, we think that some other aspects should be discussed.