Statins provide consistent protection against biliary tract cancers

For chemoprevention for biliary tract cancers (BTC) and its subtypes, statins appear to confer benefits whereas low-dose aspirin does not, according to a study. Moreover, the addition of low-dose aspirin to statins contributes no further reduction in the risk.

Researchers looked at a population-based cohort of 5.7 million adults without personal history of cancer (except nonmelanoma skin cancer). All of them had been exposed to at least one commonly prescribed drug (ie, low-dose aspirin, statins, nonsteroidal anti-inflammatory drugs [NSAIDs], and metformin), as determined from the Swedish Prescribed Drug Registry.

A total of 2,160 individuals developed BTC. Multivariable Cox regression models revealed that low-dose aspirin use was not associated with the risk of BTC overall (hazard ratio [HR], 0.93, 95 percent confidence interval [CI], 0.81–1.07), intrahepatic cholangiocarcinoma (iCCA; HR, 1.21, 95 percent CI, 0.93–1.57), extrahepatic cholangiocarcinoma (eCCA; HR, 0.80, 95 percent CI, 0.60–1.07), or gallbladder cancer (HR, 0.87, 95 percent CI, 0.71–1.06).

Statins, on the other hand, showed a protective association with BTC (HR, 0.66, 95 percent CI, 0.56–0.78), iCCA (HR, 0.69, 95 percent CI, 0.50–0.95), eCCA (HR, 0.54, 95 percent CI, 0.38–0.76), and gallbladder cancer (HR, 0.72, 95 percent CI, 0.57–0.91).

Meanwhile, the combination of low-dose aspirin and statins conferred no further reduction in the risk of all BTC subtypes as compared with statins alone.

Metformin had a null effect on the risk of BTC (HR, 0.98, 95 percent CI, 0.82–1.18), iCCA (HR, 1.06, 95 percent CI, 0.77–1.48), eCCA (HR, 1.15, 95 percent CI, 0.82–1.61), or gallbladder cancer (HR, 0.84, 95 percent CI, 0.63–1.11).

Conversely, NSAIDs were associated with a higher risk of BTC and its subtypes.