A daily dose of Aspirin may lower a woman's risk of developing the most common form of breast cancer, a new study suggests.
American researchers analyzed data from more than 127,000 women to determine if taking nonsteroidal anti-inflammatory drugs (NSAIDs), such as Aspirin, Excedrin and Bufferin, among others, would have an impact on breast cancer risk.
When the research team broke down the various breast cancer subtypes and the specific types of NSAIDs, they found that daily Aspirin use led to a 16 per cent reduction in the risk of estrogen receptor-positive breast cancer.
Estrogen receptor-positive breast cancer (ER+) accounts for about 75 per cent of breast cancer cases. ER+ cancer cells feed off the female hormone estrogen to multiply and grow.
"While our findings, along with several others, suggest at least some reduction in ER+ breast cancer associated with Aspirin use, the evidence is not conclusive and additional large studies with detailed NSAID data (including dose, frequency, duration and indication) are needed before recommending its use for breast-cancer prevention," lead study author, Dr. Gretchen Gierach of the National Cancer Institute, told CTV.ca.
"That said, we have few ways of preventing breast cancer; if Aspirin is truly a risk-reducing approach, then it's a very exciting finding."
The research team analyzed data from women enrolled in the National Institutes of Health-AARP Diet and Health Study, which was designed to investigate cancer's link to diet and other health factors.
Their findings did not show a link between NSAIDs and an overall risk of breast cancer.
Aspirin and other nonsteroidal anti-inflammatory drugs (NSAIDs) block an enzyme called cyclooxygenase, which could inhibit breast-cancer development in a variety of ways, including limiting the body's production of estrogen. When cyclooxygenase is disabled by Aspirin, the change is permanent.
The results were published Wednesday in the Bio-Med Central open access journal Breast Cancer Research.
Abstract:
Nonsteroidal anti-inflammatory drugs and breast cancer risk in the National Institutes of Health-AARP Diet and Health Study
Gretchen L Gierach, James V Lacey Jr, Arthur Schatzkin, Michael F Leitzmann, Douglas Richesson, Albert R Hollenbeck and Louise A Brinton
Introduction: By inhibiting cyclooxygenase-2, nonsteroidal anti-inflammatory drugs (NSAIDs) decrease aromatase activity and might reduce breast cancer risk by suppressing estrogen synthesis. Epidemiologic evidence for a protective role of NSAIDs in breast cancer, however, is equivocal.
Methods: We tested NSAID use for its association with breast cancer incidence in the National Institutes of Health-AARP Diet and Health Study, where 127,383 female AARP (formerly known as the American Association of Retired Persons) members with no history of cancer, aged 51 to 72 years, completed a mailed questionnaire (1996 to 1997). We estimated relative risks of breast cancer for NSAID exposures using multivariate Cox proportional hazards regression models. The state cancer registry and mortality index linkage identified 4,501 primary incident breast cancers through 31 December 2003, including 1,439 estrogen receptor (ER)-positive cancers and 280 ER-negative cancers.
Results: Proportional hazards models revealed no statistically significant association between overall NSAIDs and total breast cancer. As cyclooxygenase inhibition by aspirin (but not other NSAIDs) is irreversible, we tested associations by NSAID type. Although we observed no significant differences in risk for daily use (versus nonuse) of aspirin (relative risk = 0.93, 95% confidence interval = 0.85 to 1.01) or nonaspirin NSAIDS (relative risk = 0.96, 95% confidence interval = 0.87 to 1.05), risk of ER-positive breast cancer was significantly reduced with daily aspirin use (relative risk = 0.84, 95% confidence interval = 0.71 to 0.98) - a relationship not observed for nonaspirin NSAIDS. Neither aspirin nor nonaspirin NSAIDs were associated with risk of ER-negative breast cancer.
Conclusions: Breast cancer risk was not significantly associated with NSAID use, but daily aspirin use was associated with a modest reduction in ER-positive breast cancer. Our results provide support for further evaluating relationships by NSAID type and breast cancer subtype.
