Changing socioeconomic correlates for cancers of the upper digestive tract

Background: Cancers of the upper digestive tract have long been associated with low socio-economic levels. It has however been suggested that in recent times the social gradient for these cancers is leveling off. Patients and methods: Data from three case-control studies on oral, pharyngeal and oesophageal cancer conducted in Northern Italy during the periods 1984-1992 and 1992-1997 were combined and re-analyzed. Cases were subjects admitted to the major teaching and general hospitals in the areas under study with incident, histologically confirmed cancer of the oral cavity and pharynx (n=1126) and oesophagus (n=714). Controls were subjects admitted to the same hospitals for a wide spectrum of acute, non-neoplastic conditions, not related to smoking or alcohol consumption (n=4642). Results: In the 1980s a significant association was observed with low education and social class level. The multivariate odds ratios for oral, pharyngeal and oesophageal cancers combined was 1.78 for the lowest versus the highest educational level, and 1.75 for the lowest versus the highest social class. No consistent pattern of risk was observed with any of the socio-economic indicators considered in the studies conducted in the 1990s. Conclusions: The present study indicates that the socio-economic correlates of cancers of the upper digestive tract have changed over the last few years in Italy, with a disappearance of the social gradient.