Similar reductions in the risk of human colon cancer by selective and nonselective cyclooxygenase-2 (COX-2) inhibitors.

BACKGROUND: Epidemiologic and laboratory investigations suggest that aspirin and other nonsteroidal anti-inflammatory drugs (NSAIDs) have chemopreventive effects against colon cancer perhaps due at least in part to their activity against cyclooxygenase-2 (COX-2), the rate-limiting enzyme of the prostaglandin cascade. METHODS: We conducted a case control study of colon cancer designed to compare effects of selective and non-selective COX-2 inhibitors. A total of 326 incident colon cancer patients were ascertained from the James Cancer Hospital, Columbus, Ohio, during 2003-2004 and compared with 652 controls with no history of cancer and matched to the cases at a 2:1 ratio on age, race, and county of residence. Data on the past and current use of prescription and over the counter medications and colon cancer risk factors were ascertained using a standardized risk factor questionnaire. Effects of COX-2 inhibiting agents were quantified by calculating odds ratios (OR) and 95% confidence intervals. RESULTS: Results showed significant risk reductions for selective COX-2 inhibitors (OR = 0.31, 95% CI = 0.16-0.57), regular aspirin (OR = 0.33, 95% CI = 0.20-0.56), and ibuprofen or naproxen (0.28, 95% CI = 0.15-0.54). Acetaminophen, a compound with negligible COX-2 activity and low dose aspirin (81 mg) produced no significant change in the risk of colon cancer. CONCLUSION: These results suggest that both non-selective and selective COX-2 inhibitors produce significant reductions in the risk of colon cancer, underscoring their strong potential for colon cancer chemoprevention.

Cancer chemoprevention by cyclooxygenase 2 (COX-2) blockade: results of case control studies.

Significant use of selective cyclooxygenase-2 (COX-2) blocking agents prescribed for the treatment of arthritis during 1999 to 2005 facilitates epidemiologic investigations to illuminate their chemopreventive effects against human cancer. We therefore conducted a set of case control studies of selective COX-2 blocking agents to determine their chemopreventive potential for the four major cancers: breast, prostate, colon, and lung. Newly diagnosed cases (323 breast cancer patients, 229 prostate cancer patients, 326 colon cancer patients, and 486 lung cancer patients) were ascertained during 2002 to September 30, 2004, at The James Cancer Hospital and Solove Research Institute, The Ohio State University Medical Center, Columbus, Ohio. All cases of invasive cancer were confirmed by examination of the pathology report. Healthy controls without cancer were ascertained from hospital screening clinics during the same time period. Controls were frequency matched at a rate of 2:1 to the cases by age, gender, and county of residence. We collected information on type, frequency, and duration of use of selective COX-2 inhibitors and nonselective nonsteroidal anti-inflammatory drugs (NSAIDs). Other potentially important risk factors (smoking, drinking, body mass, medical history, blood pressure and cholesterol medications, family history of cancer, occupational history, and reproductive history for women) were also recorded for each subject. Estimates of odds ratios were obtained with adjustment for age and other potential confounders using logistic regression analysis. Use of selective COX-2 inhibitors resulted in a significant risk reduction for each type of cancer (71% for breast cancer, 55% for prostate cancer, 70% for colon cancer, and 79% for lung cancer) and an overall 68% risk reduction for all four cancers. This investigation demonstrates that COX-2 blocking agents have strong potential for the chemoprevention of cancers of the breast, prostate, colon and lung.

Reduced risk of human lung cancer by selective cyclooxygenase 2 (COX-2) blockade: results of a case control study.

We conducted a case control study of selective cyclooxygenase-2 (COX-2) blocking agents and lung cancer. A total of 492 newly diagnosed lung cancer cases were ascertained during January 1, 2002 to September 30, 2004, at The Ohio State University Medical Center, Columbus, Ohio. All cases were confirmed by examination of the pathology report. Healthy population controls without cancer were ascertained during the same time period. Controls were frequency matched at a rate of 2:1 to the cases by age, gender, and county of residence. We collected information on type, frequency, and duration of use of selective COX-2 inhibitors (primarily celecoxib or rofecoxib) and nonselective NSAIDs such as ibuprofen and aspirin. Estimates of odds ratios (OR) were obtained with adjustment for cigarette smoking, age and other potential confounders using logistic regression analysis. Odds Ratios for selective COX-2 inhibitors were adjusted for past use of other NSAIDs. Use of any selective COX-2 inhibitor for more than one year produced a significant (60%) reduction in the risk of lung cancer (OR=0.40, 95% CI=0.19-0.81). Observed risk reductions were consistent for men (OR=0.26, 95% CI=0.10-0.62) and women (OR=0.52, 95% CI=0.24-1.13) and for individual COX-2 inhibitors (OR=0.28, 95% CI=-0.12-0.67, for celecoxib and OR=0.55, 95% CI=0.19-1.56, for rofecoxib). Intake of ibuprofen or aspirin also produced significant risk reductions (OR=0.40, 95% CI=0.23-0.73 and OR=0.53, 95% CI=0.34-0.82, respectively), whereas acetaminophen, an analgesic with negligible COX-2 activity, had no effect on the risk (OR=1.36, 95% CI=0.53-3.37). This investigation demonstrates for the first time that selective COX-2 blocking agents have strong potential for the chemoprevention of human lung cancer.

Reduction in the risk of human breast cancer by selective cyclooxygenase-2 (COX-2) inhibitors.

BACKGROUND: Epidemiologic and laboratory investigations suggest that nonsteroidal anti-inflammatory drugs (NSAIDs) have chemopreventive effects against breast cancer due to their activity against cyclooxygenase-2 (COX-2), the rate-limiting enzyme of the prostaglandin cascade. METHODS: We conducted a case control study of breast cancer designed to compare effects of selective and non-selective COX-2 inhibitors. A total of 323 incident breast cancer patients were ascertained from the James Cancer Hospital, Columbus, Ohio, during 2003-2004 and compared with 649 cancer free controls matched to the cases at a 2:1 ratio on age, race, and county of residence. Data on the past and current use of prescription and over the counter medications and breast cancer risk factors were ascertained using a standardized risk factor questionnaire. Effects of COX-2 inhibiting agents were quantified by calculating odds ratios (OR) and 95% confidence intervals. RESULTS: Results showed significant risk reductions for selective COX-2 inhibitors as a group (OR = 0.29, 95% CI = 0.14-0.59), regular aspirin (OR = 0.49, 95% CI = 0.26-0.94), and ibuprofen or naproxen (0.36, 95% CI = 0.18-0.72). Acetaminophen, a compound with negligible COX-2 activity and low dose aspirin (81 mg) produced no significant change in the risk of breast cancer. CONCLUSION: Selective COX-2 inhibitors (celecoxib and rofecoxib) were only recently approved for use in 1999, and rofecoxib (Vioxx) was withdrawn from the marketplace in 2004. Nevertheless, even in the short window of exposure to these compounds, the selective COX-2 inhibitors produced a significant (71%) reduction in the risk of breast cancer, underscoring their strong potential for breast cancer chemoprevention.

Aspirin, ibuprofen, and other non-steroidal anti-inflammatory drugs in cancer prevention: a critical review of non-selective COX-2 blockade (review).

We comprehensively reviewed the published scientific literature on non-steroidal anti-inflammatory drugs (NSAIDs) and cancer and evaluated results based upon epidemiologic criteria of judgment: consistency of results, strength of association, dose response, molecular specificity, and biological plausibility. Sufficient data from 91 epidemiologic studies were available to examine the dose response of relative risk and level of NSAID intake for ten human malignancies. Dose response curves were fitted by exponential regression. Results showed a significant exponential decline in the risk with increasing intake of NSAIDs (primarily aspirin or ibuprofen) for 7-10 malignancies including the four major types: colon, breast, lung, and prostate cancer. Daily intake of NSAIDs, primarily aspirin, produced risk reductions of 63% for colon, 39% for breast, 36% for lung, and 39% for prostate cancer. Significant risk reductions were also observed for esophageal (73%), stomach (62%), and ovarian cancer (47%). NSAID effects became apparent after five or more years of use and were stronger with longer duration. Observed protective effects were also consistently stronger for gastrointestinal malignancies (esophagus, stomach, and colon). Results for pancreatic, urinary bladder, and renal cancer were inconsistent. Initial epidemiologic studies of malignant melanoma, Hodgkin's disease, and adult leukemia also found that NSAIDs are protective. A few studies suggest that ibuprofen has stronger anticancer effects than aspirin, particularly against breast and lung cancer. Overexpression of cyclooxygenase-2 (COX-2) and increased prostaglandin biosynthesis correlates with carcinogenesis and metastasis at most anatomic sites. Preclinical investigations provide consistent evidence that both selective and non-selective NSAIDs effectively inhibit chemically-induced carcinogenesis of epithelial tumors. This review provides compelling and converging evidence that regular intake of NSAIDs that non-selectively block COX-2 protects against the development of many types of cancer.

Chemoprevention of lung cancer by non-steroidal anti-inflammatory drugs among cigarette smokers.

We conducted an epidemiologic case control study of NSAIDs among 489 lung cancer patients and 978 control subjects. The case patients were diagnosed and treated during 1996-1999 at the James Cancer Hospital and Research Institute, Columbus, OH. Each lung cancer diagnosis was verified by examination of the pathology report. Population controls free of disease were obtained from health screening clinics and frequency-matched to the cases at a 2:1 rate. Matching characteristics included age, gender, and pack-years of cigarette smoking. In order to assess the effects of NSAIDs on tobacco carcinogenesis, only heavy smokers were included in the control group. Information on the use of aspirin, ibuprofen, and prescription NSAIDs was obtained by personal interviews. Effects of NSAIDs on lung cancer risk were assessed by estimating odds ratios (relative risks) with 95% confidence intervals and performing trend tests. Daily intake of NSAIDs for at least 2 years prior to interview was associated with a 68% reduction in the relative risk of lung cancer (RR, 0.32; 95% CI, 0.23-0.44; p<0.01). The inverse trend of lung cancer risk with increasing NSAID use was highly significant (p<0.01). Results were similar for men (RR, 0.41) and women (RR, 0.22), and for the individual compounds, aspirin (RR, 0.25) and ibuprofen (RR, 0.39). These results combined with the current molecular evidence suggest that regular NSAID intake may prevent tobacco carcinogenesis through COX-2 blockade.