1 Prostaglandins may precipitate or exacerbate pain and they may be produced by several tumours. 2 Non-steroidal anti-inflammatory drugs (NSAIDs) inhibit prostaglandin synthesis and may also inhibit bone metastases and enhance immune responses. 3 NSAIDs alone or in association with narcotics or psychotropics may not only afford the best pain relief in neoplastic disease, but also modify the progress of the tumour. 4 The effect of NSAIDs on the gastrointestinal tract is generally adverse.