Reduced Risk of Bone Metastasis for Patients With Breast Cancer Who Use COX-2 Inhibitors

PurposeWe hypothesize that the use of cyclooxygenase (COX)-2 inhibitors in early disease phases could protect against the development of bony metastases.Patients and MethodsThe medical charts of patients with stage II-III breast cancer diagnosed between 1999 and 2005 were reviewed. Patients were subdivided according to the use of COX-2 inhibitors after the diagnosis and for ≥ 6 months. Bivariate analyses were undertaken, and statistically significant variables were included in a multivariate logistic regression model.ResultsEleven percent of patients (74 of 644) who did not use COX-2 inhibitors developed bone metastases compared with 2% (1 of 48) of those who did use COX-2 inhibitors (Fisher exact test, P = .05). Significant predictors for bone metastases in a multivariate logistic regression model included: ≥ 3 positive nodes (odds ratio [OR], 3.26 [95% CI, 1.79-5.93]; P < .001), stage IIB-IIIC disease (OR, 3.89 [95% CI: 1.74-8.69]; P = .001) and use of COX-2 inhibitors (OR, 0.12 [95% CI, 0.02-0.88]; P = .037). Adjusting for TNM stage, of the 327 patients with stages IIB-IIIC disease, 22% (63 of 293) had bone metastases in the non–COX-2 group versus 3% (1 of 34) in the COX-2 inhibitors consumers (Fisher exact test, P = .006). In this high-risk group of patients, the calculated OR associated with COX-2 inhibitors was 0.10 (95% CI, 0.01-0.78).ConclusionThe use of COX-2 inhibitors could reduce the risk of bone metastases in stage II-III breast cancer.