Carlo Maley, PhD
Aspirin is known to lower risk for some cancers, and a new study led by a UC San Francisco scientist points to a possible explanation, with the discovery that aspirin slows the accumulation of DNA mutations in abnormal cells in at least one pre-cancerous condition.
"Aspirin and other non-steroidal anti-inflammatory drugs, which are commonly available and cost-effective medications, may exert cancer-preventing effects by lowering mutation rates," said Carlo Maley, PhD
, a member of the UCSF Helen Diller Family Comprehensive Cancer Center, and an expert on how cancers evolve in the body over time.
In the study, published June 13 in the online journal PLOS Genetics, Maley – working with gastroenterologist and geneticist Brian Reid, MD, PhD, of the Fred Hutchinson Cancer Research Center – analyzed biopsy samples from 13 patients with a pre-cancerous condition called Barrett's esophagus who were tracked for six to 19 years. In an "observational crossover" study design, some patients started out taking daily aspirin for several years, and then stopped, while others started taking aspirin for the first time during observation. The goal was to track the rate of mutations in tissues sampled at different times.
The researchers found that biopsies taken while patients were on an aspirin regimen had on average accumulated new mutations about 10 times more slowly than biopsies obtained during years when patients were not taking aspirin.
"This is the first study to measure genome-wide mutation rates of a pre-malignant tissue within patients for more than a decade, and the first to evaluate how aspirin affects those rates," Maley said.
Gender and ethnic distribution of study patients reflected the known demographics of esophageal cancer, which predominantly affects white, middle-aged and elderly men, he said. Barrett's esophagus only occasionally progresses to esophageal cancer.
Asprin's Effect of Reducing Inflammation
Cancers are known to accumulate mutations over time much more rapidly than normal tissue, and different mutations arise in different groups of cells within the same tumor. The acquisition of key mutations ultimately allows tumor cells to grow out of control, and diversity within a tumor may foster drug resistance, a phenomenon that is a major focus of Maley's research.
Read more at UCSF.edu