Background Cancer of the upper aerodigestive tract (UADT) (oral cavity, pharynx, larynx and oesophagus) is, globally, the fourth most common cancer and cause of cancer mortality. In addition to established risk factors such as tobacco and alcohol consumption, other risk factors were suggested, including human papillomavirus infection.

Objective To investigate the role of medical history (skin warts / verrucae; Candida albicans / thrush; herpetic lesions / cold sores; heartburn; regurgitation) and medication (for heartburn; for regurgitation; aspirin) use in UADT cancer risk.

Methods A case-control study conducted in 10 European countries.

Results There were 1779 cases of UADT cancer (all SCC) and 1993 controls. Having had warts / verrucae and history of Candida / thrush infection protective for UADT cancers (OR 0.80, 95% CI (0.68 to 0.94) and 0.73 (0.60 to 0.89), respectively) but there was no association with herpetic lesions.

Neither symptoms of gastro-oesophageal reflux (heartburn or regurgitation) nor medication for associated symptoms were associated with risk of UADT cancer. When considered by sub-site, regurgitation was associated with a non-significant increased risk for cancer of the oesophagus (1.47; 0.98 to 2.21).

Regular aspirin use (at least once a week for a year) was not associated with risk of UADT cancer. When considered by sub-site, it had protective effect for cancer of oesophagus (0.51; 0.28 to 0.96) and non-significant protective effect for cancers of hypopharynx (0.53; 0.28 to 1.02) and larynx (0.74; 0.54 to 1.01).

Conclusion There is conflicting evidence regarding association between medical history and medication use and UADT cancer risk.