Clinical Value of Gastrofiberscopy in Preoperative Cases of Primary Lung Cancer

The authors experienced 5 cases (2.3%: out of 222 cases) of gastric cancer accompanied by primary lung cancer since 1967 to 1975 in which the second primary cancer was detected serendipitously. These experiences reminded us of the possibility that gastric cancer may frequently be accompanied by lung cancer. Since 1981, to find out the synchronous gastric cancers, we have actively performed gastrofiberscopy in lung cancer cases, especially preoperatively. Out of 358 cases with lung cancer from 1981 to 1985, 6 synchronous (1.7%) and 12 metachronous (3.4%) gastric cancer cases were diagnosed by gastric endoscopy. During the next half decade from 1986 to 1990, we found many more cases of gastric cancer consisting of 10 synchronous (2.8%) and 17 metachronous (4.8%) cases out of 352 cases of primary lung cancer, suggesting the increasing combined incidence of both cancers. Importantly, this incidence was much higher than the discovery rate in mass surveys for gastric cancer. No significant difference was observed between resectable and nonresectable cases of primary lung cancer. We conclude that it is very important to perform gastric endoscopy in cases with lung cancer, particularly in preoperative cases of lung cancer in order to detect synchronous gastric cancer.