Researchers have now revealed that aspirin can increase the dismal survival chances for biliary tract cancers.
Because these rare diseases may not produce symptoms until the later stages, 60% to 70% of patients with biliary tract cancers present with later-stage disease. Less than 10% have resectable tumors at the time of diagnosis, and 50% present with lymph node metastasis. As a result, the median survival is under a year, with five-year survival rates ranging from 5% to 15%.
"There is a critical need for treatments that improve [biliary tract cancer] survival," write the researchers in their new publication in JAMA Oncology, led by first author Sarah S. Jackson, PhD, a postdoctoral fellow, and senior author Jill Koshiol, PhD, an investigator, both in the Infections and Immunoepidemiology Branch of the National Cancer Institute Division of Cancer Epidemiology and Genetics. "Aspirin has been proposed as a treatment to reduce cancer mortality because it may slow cancer growth through the inhibition of both cyclooxygenase, which promotes inflammation and cell proliferation, and platelet aggregation, which may slow the metastatic spread of cancer."
In examining the possible association between postdiagnosis aspirin use and survival of biliary tract cancers, the researchers analyzed data, including all-cause deaths, on adults diagnosed with biliary tract cancers from 1990 through 2017 in the United Kingdom's Clinical Practice Research Datalink (CPRD), an electronic medical record database. The study included 2,934 patients with biliary tract cancers, of whom 23% had gallbladder cancer, 53% had cholangiocarcinoma, 8% had ampulla of Vater cancer (AVC), and 16% had overlapping lesions of the biliary tract.
Postdiagnosis aspirin users were defined as those who received one or more aspirin prescriptions within 30 days of diagnosis, as recorded in the CPRD. Of the aspirin users, 96% were prescribed a 75-mg dose. Nine percent of patients were aspirin users at baseline, and an additional 12% began using aspirin after their diagnosis. Aspirin users were more likely to be older patients and current statin users, and they were more likely to have used aspirin prior to their diagnosis. They were also more likely to have heart disease and other comorbidities. The researchers adjusted their analysis for age at diagnosis, sex, comorbidities, statin use at diagnosis, indicators of a healthy lifestyle, and year of diagnosis.
There were 2,415 deaths, comprising 82% of the study population. Median overall survival was 5.8 months. Postdiagnosis aspirin use decreased risk of death in patients with gallbladder cancer (hazard ratio of 0.63), cholangiocarcinoma (hazard ratio of 0.71), AVC (hazard ratio of 0.44), and overlapping biliary tract cancers (hazard ratio of 0.68). While all postdiagnosis aspirin users had a reduced risk of death, those with no prior history of aspirin use derived a larger benefit than did prevalent users.
"We observed a reduced risk of death from postdiagnosis aspirin users across all [biliary tract cancer] types. Platelet activation protects tumor cells from elimination, enhances metastatic cell growth, and enables cancerous cells to spread via the bloodstream. Aspirin may slow the metastatic spread of cancer cells through inhibition of platelet aggregation, improving [biliary tract cancer] survival," conclude the investigators.
While the researchers acknowledge a limitation in the lack of data on cancer stages and chemotherapy regimens received, they highlight one notable fact: "The survival benefit of aspirin observed in our study is on par with the current standard of care."
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