A study published in the April 23rd issue of Science Translational Medicine found that administering aspirin to individuals with high levels of RNA for a specific enzyme, 15-hydroxyprostaglandin dehydrogenase (15-PGDH), reduced their risk of colorectal cancer by half. However, administering aspirin to individuals with low levels of 15-PGDH provided no reduction in colorectal cancer risk.1
According to the American Cancer Society, colorectal cancer is the second leading cause of cancer-related deaths in the United States and is expected to account for approximately 50,000 deaths in 2014.2 Aspirin was previously thought to reduce the risk of colorectal cancer; however, its mechanism of action has remained unclear.1 “15-PGDH and aspirin have similar mechanisms of action; both lower levels of prostaglandin in the body. It appears that their synergistic effect also has an impact on lowering colorectal cancer risk,” said senior author Sanford Markowitz, MD, PhD, of Case Western Reserve School of Medicine in Cleveland, OH.
High Levels of 15-PGDH and Aspirin Tied to Colorectal Cancer Prevention
As part of the multi-center Harvard-based Nurses’ Health Study and Health Professionals Follow-Up Study that included 127,865 study participants, the investigators analyzed tissue samples from 270 patients with colorectal cancer .1 The investigators at Massachusetts General and Dana-Farber Cancer Institute, both in Boston, MA, dissected normal colorectal tissue from the pathology specimens and forwarded them to Case Western to identify which samples had high versus low levels of 15-PGDH. “We found that among the individuals with high 15-PGDH levels, there was not a lot of colorectal cancer among those who took aspirin, demonstrating that the combination of aspirin and high 15-PGDH levels prevented colorectal tumors,” said Dr. Markowitz in an interview with ChemotherapyAdvisor.com.
Biomarker Identification Aids in Determining Which Patients Could Benefit From Aspirin
Based on these findings, clinical practitioners may have a new biomarker to aid them in identifying individuals at high risk for colorectal cancer who would benefit from aspirin.1 “We have known for a while that aspirin reduces the risk of colorectal cancer but we weren’t sure of the mechanism of action. We have been reluctant to prescribe aspirin because it was not clear whether the risks of stomach ulcers and stomach bleeding outweigh the benefits for colorectal cancer prevention. However, now we have a method for classifying patients who will benefit from aspirin,” said Dr. Markowitz.
Further Study Warranted
The results of this retrospective analysis are promising, but further prospective analysis is needed. “We are hoping to do a follow-up study evaluating patients prospectively, rather than retrospectively. However, this is the first study to demonstrate the benefits of aspirin and provide a specific biomarker, high levels of 15-PGDH, which helps guide clinicians as to which patients would benefit from aspirin,” said Dr. Markowitz.
- Fink SP, Yamauchi M, Nishihara R, et al. Aspirin and the Risk of Colorectal Cancer in Relation to the Expression of 15-Hydroxyprostaglandin Dehyrogenase (HPGD). Sci Transl Med. 2014; 6 (233):1-8.
- American Cancer Society (ACS). What are the key statistics about colorectal cancer? Available at: http://www.cancer.org/cancer/colonandrectumcancer/detailedguide/colorectal-cancer-key-statistics. Accessed April 30, 2014.