Aspirin and non-steroidal anti-inflammatory drug use and the risk of upper aerodigestive tract cancer

BACKGROUND: Aspirin and other non-steroidal anti-inflammatory drugs (NSAIDs) are widely used as analgesics and preventative agents for vascular events. It is unclear whether their long-term use affects cancer risk. Data on the chemopreventative role of these drugs on the risk of the upper aerodigestive tract cancer (UADT) are insufficient and mostly refer to oesophageal cancer. The aim of this study was to investigate the effect of aspirin and other NSAIDs on the risk of UADT cancers. METHODS: A nested case–control study using the Primary Care Clinical Informatics Unit (PCCIU) database. Conditional logistics regression was used for data analysis. RESULTS: There were 2392 cases of UADT cancer diagnosed between 1996 and 2010 and 7165 age-, gender- and medical practice-matched controls from 131 general medical practices. Mean age of cases was 66 years (s.d. 12) and most were male (63%). Aspirin was prescribed in a quarter of cases and controls, COX-2 inhibitors in 4% of cases and 5% of controls and other NSAIDs in 33% of cases and 36% of controls. Aspirin prescription was associated with a nonsignificant risk reduction of cancer of UADT (adjusted OR=0.9, 95% CI=0.8, 1.0), head and neck (HN; adjusted OR=0.9, 95% CI=0.7, 1.1) or the oesophagus (adjusted OR=0.8, 95% CI=0.7, 1.0). Similar results were found for COX-2 inhibitors prescription. Prescription of other NSAIDs was associated with significantly reduced risk of cancer of UADT (adjusted OR=0.8, 95% CI=0.7, 0.9), HN (adjusted OR=0.8, 95% CI=0.7, 0.9) and the oesophagus (adjusted OR=0.8, 95% CI=0.7, 0.9). An increased volume of aspirin prescriptions was associated with a significant risk reduction (test for trend P<0.001). CONCLUSIONS: The decreased risk of cancer of the UADT associated with the use of non-COX-2 inhibitors, NSAIDs and long-term aspirin therapy warrants further exploration of the benefits vs risks of the use of these agents.