Recent time trends in cancer of the oesophagus and gastric cardia in the region of Calvados in France, 1978-1995: a population based study

The incidence of oesophageal cancer differs from country to country, and ev en between areas of the same country. Many studies in recent years have sho wn an upward trend of a particular histologic type: adenocarcinoma of the o esophagus. It is difficult to precisely locate adenocarcinomas situated at the junction between the oesophagus and the gastric cardia, Clear criteria to define and classify such tumours are essential in order to analyse their evolution. The present study describes the changing incidence of cancers o f the oesophagus and gastric cardia according to histologic type from 1978 to 1995 in Calvados, the highest-risk French region with two different topo graphic classifications of adenocarcinomas: one based on Misumi's criteria and the other based on local extension of cancer. In total, 1835 cancers of the oesophagus and gastric cardia were diagnosed in this period. Incidence rates for oesophageal and gastric cardia cancers standardized on the world population were 24.4/10(5) and 2.4/10(5) in men and 1.4/10(5) and 0.4/10(5 ) in women, respectively. The time trend in the incidence of squamous cell cancers was downward in men -0.74 (P < 10(-6)) and stable in women +0.04 (P = 0.65). Regarding adenocarcinomas, with the classification based on Misum i's categories, there was a slight but significant upward trend for oesopha geal adenocarcinoma in men [mean annual variation of +0.09 (P < 10(-5))] wh ile the tendency was downward and significant for gastric cardia adenocarci noma [mean annual variation of -0.09 (P < 10(-4))]. When adenocarcinomas of the oesophagus and those of the gastric cardia with oesophageal involvemen t are taken together (second classification), there was an upward trend whi ch was not significant in men and was significant in women. There was no su ch upward trend in adenocarcinomas limited to the gastric cardia and/or inv olving the stomach. Because of the difficulties in determining accurate loc alization routinely in population-based studies, it seems sensible to precl ude classification biases in recommending the grouping together of gastric cardia adenocarcinomas with oesophageal adenocarcinomas, at least with thos e among the latter occurring in the lower third of the oesophagus. (C) 1999 Lippincott Williams & Wilkins.