Patients with prostate cancer are less likely to develop oesophageal adenocarcinoma: could androgens have a role in the aetiology of oesophageal adenocarcinoma?

Oesophageal adenocarcinoma (OAC) is more common in men. Androgens may therefore contribute to the pathogenesis of OAC. Prostate cancer (PC), an androgen sensitive tumor with a long natural history, may allow insights into this putative association. West Midlands Cancer Intelligence Unit data from 1977 to 2004 were examined to identify patients with a first malignant primary of PC. Patients were followed until diagnosis of a second primary cancer, death or end of the time period. Age- and period-adjusted standardized incidence ratios (SIR) were calculated as an estimate of the relative risk of a second malignant primary of the oesophagus. Between 1977 and 2004, 44,819 men within the West Midlands developed PC as a first primary malignancy. After exclusion for lack of follow-up, 38,627 men were eligible, providing 143,526 person years at risk for analysis. 86 second primary oesophageal cancers were observed, compared with 110 expected, resulting in an SIR of 0.78 (95% CI 0.62-0.96). There was a reduced risk of OAC 0.7 (0.5-0.95) but not of oesophageal squamous cell carcinoma (OSCC) 1.03 (0.69-1.47). The risk of developing OAC, but not OSCC, is lower than expected in patients with PC. A diagnosis of PC may be associated with aetiological factors that are negatively associated with OAC, or anti-androgen therapy may influence the development of OAC.