Migraine history, nonsteroidal anti-inflammatory drug use, and risk of postmenopausal endometrial cancer

Use of nonsteroidal anti-inflammatory drugs and risk of endometrial cancer: a nationwide case-control study

PURPOSE

We examined the association between use of low-dose aspirin and non-aspirin nonsteroidal anti-inflammatory drugs (NSAIDs) and endometrial cancer risk in a nationwide case-control study.

METHODS

Cases were all women in Denmark diagnosed with endometrial cancer during 2000-2009. Age-matched female controls were randomly selected by risk-set sampling. Information on NSAID use was collected from the Prescription Registry and classified according to duration and intensity. Conditional logistic regression was used to calculate odds ratios (ORs) and 95 % confidence intervals (CIs), adjusting for potential confounders. Analyses were stratified by endometrial cancer type, and potential effect modification by parity, obesity, and hormone replacement therapy (HRT) use was investigated.

RESULTS

We identified 5,382 endometrial cancer cases and 72,127 controls. Endometrial cancer was not associated with use of low-dose aspirin (OR 0.97, 95 % CI 0.89-1.05) or non-aspirin NSAIDs (OR 0.96, 95 % CI 0.91-1.02) compared with nonuse. The ORs did not vary with increasing duration or intensity of NSAID use or with type of endometrial cancer. Interaction analyses showed reduced endometrial cancer risk associated with low-dose aspirin use among nulliparous women (OR 0.82, 95 % CI 0.70-0.95) and with non-aspirin NSAID use among women having used HRT (OR 0.90, 95 % CI 0.82-0.99).

CONCLUSIONS

We found no association between use of NSAIDs and endometrial cancer risk overall, although there were some indications of risk reductions associated with low-dose aspirin use among nulliparous women and with non-aspirin NSAID use among women having used HRT.

Non-steroidal anti-inflammatory drugs and cancer risk in women: results from the Women's Health Initiative

The use of non-steroidal anti-inflammatory drugs (NSAIDs) has been associated with reduced risks of cancers at several sites in some studies; however, we recently reported no association between their use and total cancer risk in women in a prospective study. Here we examine the association between NSAIDs and total and site-specific cancer incidence in the large, prospective Women's Health Initiative (WHI). Women (129,013) were recruited to participate in the WHI at 40 US clinical centers from 1993 to 1998 and followed prospectively. After 9.7 years of follow-up, 12,998 incident, first primary, invasive cancers were diagnosed. NSAID use was systematically collected at study visits. We used Cox proportional hazards regression models to estimate multivariable-adjusted hazard ratios (HR) and 95% confidence intervals (CI) for associations between NSAIDs use and total and site-specific cancer risk. Relative to non-use, consistent use (i.e., use at baseline and year 3 of follow-up) of any NSAID was not associated with total cancer risk (HR 1.00, 95% CI: 0.94-1.06). Results for individual NSAIDs were similar to the aggregate measure. In site-specific analyses, NSAIDs were associated with reduced risks of colorectal cancer, ovarian cancer, and melanoma. Our study confirms a chemopreventive benefit for colorectal cancer in women and gives preliminary evidence for a reduction of the risk of some rarer cancers. NSAIDs' benefit on cancer risk was therefore limited to specific sites and not evident when total cancer risk was examined. This information may be of importance when NSAIDs are considered as chemopreventive agents.

Non-steroidal anti-inflammatory drugs and endometrial cancer risk in the VITamins And Lifestyle (VITAL) cohort

OBJECTIVE

Chronic inflammation may be an important factor in the initiation and promotion of endometrial cancer. Use of non-steroidal anti-inflammatory drugs (NSAIDs), however, has been inconsistently associated with endometrial cancer risk.

METHODS

22,268 female residents of western Washington State, ages 50-76, completed a baseline questionnaire in 2000-2002 and reported on their use of individual NSAIDs over the past 10years. Use was categorized as none, low (<4days/week or <4years), and high (≥4days/week and ≥4years). Over 9years of follow-up, 262 incident invasive endometrial cancers were identified. Multivariable proportional hazards models were used to estimate hazard ratios (HR) and 95% confidence intervals (CI).

RESULTS

Relative to non-use, high use of aspirin was inversely associated with endometrial cancer risk (HR 0.64, 95% CI: 0.41-1.01; P trend=0.03). Findings were stronger for regular-strength than low-dose aspirin. High use of non-aspirin NSAIDs (HR 1.15, 95% CI: 0.68-1.95), including ibuprofen (HR 1.29, 95% CI: 0.73-2.28), and naproxen (HR 1.08, 95% CI: 0.39-2.95) was not associated with risk. In subgroup analyses, findings for aspirin were strongest for cancers of endometrioid histology and were restricted to non-smokers.

CONCLUSIONS

This study provides additional evidence that use of aspirin, but not non-aspirin NSAIDs, may reduce the risk of endometrial cancer, especially in estrogen-mediated cases; however additional prospective studies with high-quality measurement of NSAID use are needed. Aspirin should continue to be examined as a potential agent for cancer chemoprevention.