Aspirin use apparently offers protection against bile duct cancer, according to the findings of a recently published study. Bile duct cancer, or cholangiocarcinoma (CCA), is a particularly aggressive and lethal cancer that has been increasing in incidence in the United States.1
Cholangiocarcinoma is classified into 3 subtypes by location: intrahepatic (iCCA), perihilar (pCCA), and distal (dCCA). Each type has diverse genetics and manifestations, requires different management, and patient outcomes are dissimilar. For these reasons, experts consider the subtypes as separate diseases. All 3 subtypes have poor prognosis. For patients with iCCA or pCCA, in particular, 5-year survival rates after complete resection are 30% to 40%; without surgery, patients live only 12 to 15 months.
DAILY ASPIRIN AND CCA RISK
Studies have shown daily aspirin administration has a beneficial effect on the risk for some gastrointestinal cancers. Aspirin has an antiplatelet effect as a result of its action on the COX-1 isozyme. It also has anti-inflammatory action resulting from its COX-2 isozyme inhibition. Overexpression of COX-2 is a source of inflammation and a factor in the development of several cancer types, including cholangiocarcinoma, which is caused by continuous inflammation. Therefore, Jonggi Choi, MD, Roongruedee Chaiteerakij, MD, PhD, and Lewis Roberts, MBChB, PhD, of the Mayo Clinic College of Medicine, Rochester, Minnesota, and colleagues undertook a large hospital-based case-control study to evaluate the risk factors for cholangiocarcinoma and the effect of aspirin use on the disease.
For their project, the researchers used data from the Mayo Clinic Biobank and Hepatobiliary Neoplasia registries and from the Rochester Epidemiology Project. The project included a cohort of 2395 patients with cholangiocarcinoma who were seen at the Mayo Clinic from 2000 through 2014 and a control group of 4769 healthy persons matched for sex, age, race, and place of residence. A total of 591 (24.7%) patients with cholangiocarcinoma and 2129 (44.6%) controls were aspirin users. The researchers classified aspirin dose as low-dose aspirin (81-162 mg/day) or high-dose aspirin (325 mg/day). Current aspirin use was defined as taking aspirin at least once a week at the index date.