Bens A, et al. - In view of the finding that inhibition of the cyclooxygenase (COX)-2 enzymes inhibits breast cancer development, researchers performed this nationwide cohort study to assess the risk of contralateral breast cancer (CBC) in relation to use of COX-2 selective or other non-aspirin non-steroidal anti-inflammatory drugs (NSAIDs) after the diagnosis of breast cancer among Danish breast cancer patients. Participants were 52,723 women diagnosed with breast cancer between 1996 and 2012, identified from the clinical database of the Danish Breast Cancer Group. The required information on non-aspirin NSAID use, CBC and potential confounding variables was extracted from nationwide registries. According to findings, non-aspirin NSAID use was not associated with an attenuated risk of CBC, regardless of the COX-2 selectivity.