Association between nonsteroidal anti-inflammatory drugs and prostate cancer occurrence.

UNLABELLED: Prostate cancer is the most common malignancy among men in Western nations. Previous studies indicate that nonsteroidal anti-inflammatory drugs have an inhibitory effect on prostate cancer cells. We evaluated the association between frequent use of nonsteroidal anti-inflammatory drugs and prostate cancer occurrence. METHODS: We conducted a nested case-control study using medical administrative databases. All men older than 65 years of age who had filled at least one prescription for nonselective nonsteroidal anti-inflammatory drugs, cyclooxygenase-2 inhibitors (coxibs), aspirin, or acetaminophen between January 1999 and December 2002 were eligible. Among this group, we identified men who underwent prostate biopsy between January 2000 and June 2002 and did not have a diagnosis of any cancer in the preceding 2-year period. Cases were those with a diagnosis of prostate cancer. Controls were those who did not receive a diagnosis of any cancer. Logistic regression models were used to determine associations between prostate cancer occurrence and frequent exposure (more than 4 months) to nonsteroidal anti-inflammatory drugs/cyclooxygenase-2 inhibitors or aspirin during the prior 2 years in comparison with no exposure to any of these drugs, adjusting for age and prior finasteride use. RESULTS: We identified 2025 cases and 2150 controls. Older men were at greater risk for developing prostate cancer. Exposure to nonsteroidal anti-inflammatory drugs/cyclooxygenase-2 inhibitors was associated with a reduced likelihood of prostate cancer (odds ratio [OR], 0.71; 95% confidence interval [CI], 0.58-0.86) as was exposure to aspirin (OR, 0.84; 95% CI, 0.74-0.96). DISCUSSION: Our results suggest that among men 65 years of age or older, frequent use of nonsteroidal anti-inflammatory drugs/cyclooxygenase-2 inhibitors and use of aspirin are associated with a reduced risk of prostate cancer.

Association between frequent use of nonsteroidal anti-inflammatory drugs and breast cancer.

BACKGROUND: Eighty percent of all breast cancers and almost 90% of breast cancer deaths occur among post-menopausal women. We used a nested case control design to examine the association between nonsteroidal anti-inflammatory drug (NSAID) use and breast cancer occurrence among women over 65 years of age. The cyclooxygenase (COX)-2 enzyme is expressed more in breast cancers than in normal breast tissue. COX-2 inhibition may have a role in breast cancer prevention. METHODS: In the Canadian province of Quebec, physician services are covered through a governmental insurance plan. Medication costs are covered for those > or = 65 years of age and a publicly funded screening program for breast cancer targets all women 50 years of age or older. We obtained encrypted data from these insurance databases on all women > or = 65 years of age who filled a prescription for COX-2 inhibitors, non-selective NSAIDs (ns-NSAIDs), aspirin, or acetaminophen between January 1998 and December 2002. Cases were defined as those women who have undergone mammography between April 2001 and June 2002 and had a diagnosis of breast cancer within six months following mammography. Controls included those who have undergone mammography between April 2001 and June 2002 without a diagnosis of any cancer during the six months following mammography. The exposure of interest, frequent NSAID use, was defined as use of ns-NSAIDs and/or COX-2 inhibitors for > or = 90 days during the year prior to mammography. Frequent use served as a convenient proxy for long term chronic use. RESULTS: We identified 1,090 cases and 44,990 controls. Cases were older and more likely to have breast cancer risk factors. Logistic regression models adjusting for potential confounders showed that frequent use of ns-NSAIDs and/or COX-2 inhibitors was associated with a lower risk of breast cancer (OR: 0.75, 95% confidence interval 0.64-0.89). Results were similar for COX-2 inhibitors (0.81, 0.68-0.97) and ns-NSAIDs (0.65, 0.43-0.99), when assessed separately. Frequent use of aspirin at doses > 100 mg/day in the year prior to mammography was also associated with a lower risk of breast cancer (0.75, 0.64-0.89). However, use of aspirin at doses < or = 100 mg/day did not have any association with breast cancer (0.91, 0.71-1.16). CONCLUSION: Women who use NSAIDs or doses of aspirin > 100 mg frequently may have a lower risk of breast cancer.

Effect of chronic intake of NSAIDs and cyclooxygenase 2-selective inhibitors on esophageal cancer incidence.

BACKGROUND & AIMS: A rising incidence and a poor survival rate make esophageal cancer a major health issue, hence the need for chemoprevention. We investigated the effects of the selective cyclooxygenase 2 inhibitors (coxibs), rofecoxib and celecoxib, the nonselective nonsteroidal anti-inflammatory drugs (NSAIDs), and aspirin on esophageal cancer. METHODS: This nested case-control study used data from a government-run insurance database on patients 66 years and older who underwent esophageal imaging (esophagogastroduodenoscopy or barium swallow) between January 1999 and September 2002. Logistic regression models were used to determine the effect of chronic exposure, by using as proxy at least 30 days of use of the drugs of interest in the past year, on the occurrence of esophageal cancer. RESULTS: The study included 251 cases and all 86,644 eligible control subjects. Patients more likely to have esophageal cancer (odds ratio, 95% confidence interval) were men (3.42, 2.62-4.48) and older subjects (those 75-84 years and those > or =85 years: 1.40, 1.08-1.82 and 1.69, 1.05-2.72, respectively). Chronic exposure to coxibs or NSAIDs was associated with a significant risk reduction for esophageal cancer (0.63, 0.40-0.98 and 0.47, 0.24-0.93, respectively). Assessed separately, the point estimates were slightly lower for rofecoxib than for celecoxib when examining a possible duration-response effect, although all 95% confidence intervals overlapped (celecoxib: 0.51, 0.27-0.98; 0.30, 0.11-0.82; 0.39, 0.14-1.05; rofecoxib: 0.39, 0.16-0.96; 0.37, 0.12-1.16; 0.33, 0.08-1.36 for exposures of > or =30, > or =60, and > or =90 days, respectively). CONCLUSIONS: Chronic intake of rofecoxib and celecoxib and of nonselective NSAIDs appears to be associated with a decreased incidence of esophageal cancer.