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 even between areas of the same country. Many studies in recent years have shown an upward trend of a particular histologic type: adenocarcinoma of the oesophagus. 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 of the oesophagus and gastric cardia according to histologic type from 1978 to 1995 in Calvados, the highest-risk French region with two different topographic 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 Misumi's categories, there was a slight but significant upward trend for oesophageal adenocarcinoma in men [mean annual variation of +0.09 (P < 10 -5 )] while the tendency was downward and significant for gastric cardia adenocarcinoma [mean annual variation of -0.09 (P < 10 -4 )]. When adenocarcinomas of the oesophagus and those of the gastric cardia with oesophageal involvement are taken together (second classification), there was an upward trend which was not significant in men and was significant in women. There was no such upward trend in adenocarcinomas limited to the gastric cardia and/or involving the stomach. Because of the difficulties in determining accurate localization routinely in population-based studies, it seems sensible to preclude classification biases in recommending the grouping together of gastric cardia adenocarcinomas with oesophageal adenocarcinomas, at least with those among the latter occurring in the lower third of the oesophagus.