[Characteristics of gastric cancer detected by mass survey. Comparison with those of outpatients].

The characteristics of gastric cancers detected by mass survey were studied by comparison with those of outpatients attending our hospital. Form 1966 to 1985, a total of 290,987 examinees were screened by gastric mass survey at our Mass Survey Center. Among them, 474 cases (0.16%) of gastric cancer were detected, and of these, 254 cases (52%) were early gastric cancer. Upon comparison of macroscopic types of surgically treated cancers, there were 152 cases (39.6%) out of 784 cases in the mass survey group and 658 cases (21.3%) out of 3,091 cases in the outpatient group having the depressed type and 11% in the former and 5.5% in the latter having the elevated type of early gastric cancer. As for the prognosis of cancers in both groups, the 5- and 10-year survival rates of 274 cases in the mass survey group and 1,859 cases in the outpatient group undergoing resection between 1964 and 1974 were compared. It was found that 80.0% for 5 years and 78.5% for 10 years in relative survival rates were obtained in the mass survey group, and 56.2% for 5 years and 55.1% for 10 years in the outpatient group. This difference in survival rate was due to the fact that the mass survey group had a high ratio of early gastric cancer than the outpatient group, and that even the advanced serosal cancer former group had less lymph node metastasis than the latter group.