Research by scientists at Mayo Clinic suggest that some women with an elevated risk of developing breast cancer may benefit from taking anti-inflammatory medications.
This is the conclusion based on a poster presented at the San Antonio Breast Cancer Symposium, held December 10 – 14, 2019 in San Antonio, Texas.
“Several studies have evaluated whether the use of anti-inflammatory medications such as aspirin, ibuprofen and naproxen affect a woman’s risk of developing breast cancer,” noted Amy C. Degnim, MD, a breast surgical oncologist at Mayo Clinic in Rochester, Minnesota, who focuses on improving the ability to predict breast cancer risk for individual women by studying breast tissue for very early signs of premalignant change and leads a team that pursues multiple research projects based on the Mayo Clinic Benign Breast Cohort, involving approximately 15,000 women.
“Little is known about how use of these (anti-inflammatory) drugs might affect their risk after a benign breast biopsy,” Degnim added, pointing to the approximately one million women who receive a diagnosis of benign breast disease annually in the United States and having this history increases their risk of developing breast cancer.
Benign breast biopsy
To understand the relationship between benign breast disease (BBD), increased breast cancer risk and the use of aspirin and other NSAIDs, researchers surveyed 4,498 women who had undergone a benign breast biopsy at Mayo Clinic between 1992 and 2001. The investigators asked these women to report which types of these medications they had used and for how long, including average number of days used per month (0, 1-7, 8-28 and >28). The also obtained information on which women had developed breast cancer at any point in the years after their initial benign biopsy.
The medications were categorized into three classes including aspirin, ibuprofen (+ plus other prostaglandin synthesis inhibitors) and COX inhibitors.
“We found that women who reported using ibuprofen or naproxen had an approximately 40% reduction in breast cancer risk, while women who reported using aspirin had no reduction in breast cancer risk,” Degnim said.
“Women who used the drugs more frequently on a regular basis also had greater protection from breast cancer,” she explained.
Survey data was available for 3,089 (69%) of the participating women in the cohort. The median age of these women was 49 year of age. They did not differ in breast cancer risk from women who did not provide data on NSAID use (p=0.46).
A total of 313 (10.1%) women developed breast cancer with median follow-up of 17 years. The investigators noted that age was significantly associated with use of all types of NSAIDs, with increasing use in older women. They also noted that BMI at the time of biopsy, severity of the benign breast disease findings, and involution in background lobules, were also associated with NSAID use. These additional factors were adjusted for in the exploitative risk analyses.
Women taking NSAIDs had a significantly lower risk of breast cancer than women not taking these anti-inflamatory agents (HR 0.76, CI 0.59-0.98, p=0.03). An increasing frequency of using NSAID was significantly associated with lower breast cancer risk (HRs 0.81, 0.79, and 0.70 for regular use 1-7, 8-28, and >28 days/month), trend p=0.02.
An analyses of drug classes revealed that women participating in the survey using ibuprofen (HR 0.61, CI 0.42-0.89, p=0.01) and or COX inhibitors (HR 0.59, CI 0.39-0.89, p=0.01) were associated with decreased risk of breast cancer.
The investigators observed that in particular the use if COX inhibitors demonstrated a strong dose response effect with increasing use (HRs 0.97, 0.52, and 0.47 for regular use 1-7, 8-28, and >28 days/month), trend p<0.01.
However, in their analyses, the investigators also observed that the use of aspirin was not associated with BC risk (HR 0.88, CI 0.64-1.21, p=0.44).
Degnim explained that these findings suggest that women who have had a benign breast biopsy may benefit from medications that reduce inflammation, except for aspirin, in terms of reducing later breast cancer risk. However, she also cautioned, that this study was not a clinical trial and does not recommend that all women should take these medications to reduce their breast cancer risk.
“Our results support the need for a clinical trial to further investigate the risks and benefits of taking these medications to lower breast cancer risk,” Degnim concluded.
Degnim AC, Vierkant R, Winham S, Frost M, Visscher D, Carter J, Kaggal S, Cunningham J, et al. NSAID use and breast cancer risk in a retrospective cohort of women with benign breast disease. Poster presentation presented at the 2019 San Antonio Breast Cancer Symposium. December 13, 2019, 5:00 PM – 7:00 PM. Session/Poster P5-08-06.[Abstract]