WHI analysis links NSAID use with lower colorectal cancer mortality

Postmenopausal women who reported at least 10 years of nonsteroidal anti-inflammatory drug use at the time of enrollment in the Women’s Health Initiative had a lower risk for death from colorectal cancer compared with women who reported no NSAID use at study enrollment.

The Hutchinson Center's Anna Coghill presented the Public Health Sciences Division's data during the American Association for Cancer Research’s 10th annual International Conference on Frontiers in Cancer Prevention Research in Boston.

Specifically, the analysis of the landmark WHI study links:

• Lower colorectal cancer mortality rates with consistent NSAID use at both study enrollment and three years later
• Lower colorectal cancer mortality rates with at least 10 years of reported NSAID use.

"Our results suggest that NSAID use is associated with lower colorectal cancer mortality among postmenopausal women who use these medications more consistently and for longer periods of time," said Coghill, a project coordinator for the Newcomb Studies group.

Coghill and colleagues evaluated the association between aspirin and nonaspirin NSAID use and colorectal cancer mortality in 160,143 postmenopausal women enrolled in WHI who did not report a history of colorectal cancer at baseline. The study population included women enrolled in the WHI clinical trials, as well as the women, enrolled in the WHI observational study.

"The WHI study population represents a large and well-characterized cohort of postmenopausal women, and the medication data collected in this cohort made it possible for us to investigate multiple types, durations and strengths of NSAID use," said Coghill, a doctoral student in epidemiology at the University of Washington.

The researchers found 2,119 cases of colorectal cancer and 492 deaths from the disease.

Importance of drug use duration

Coghill’s team found that reported use of NSAIDs such as aspirin, ibuprofen and prescription NSAIDs at baseline, by itself, was not associated with colorectal cancer mortality.

However, women in the study who reported using NSAIDs at both study enrollment and three years after study enrollment had approximately 30 percent lower rates of death due to colorectal cancer than women who reported no NASID use or use at only one of these two time points. They also observed significant reductions in colorectal cancer mortality among women who reported at least 10 years of NSAID use at study enrollment compared with those who reported no use.

"The results of our study help to further clarify the importance of different durations of NSAID use over time for the risk for dying from colorectal cancer," Coghill said.

[Adapted from an AACR news release]