In order to evaluate the effectiveness of a mass screening program for stomach cancer, a case-control study was conducted in Nose town in Osaka, Japan. The case series consisted of all deaths from stomach cancer during the period 1969-1981 (54 in males and 37 in females). For each case, 3 controls of the same sex and from the same precinct as the case, and born within 5 years of the case birth-year, were selected at random from Nose town residents alive at the date of death of the relevant case. We then investigated whether each case and corresponding controls had ever had screening tests before the date of diagnosis of the case. From the matched analysis of the distribution of screening in case-control combination, the odds ratio of screened vs. unscreened among those who died from stomach cancer compared to those who did not was calculated as 0.595 (90% confidence interval: 0.338-1.045) among males and 0.382 (0.185-0.785) among females. When the screening tests conducted within 12 months of diagnosis were ignored on the presumption that they were symptom-related, the odds ratio was calculated as 0.519 (0.297-0.905) among males and 0.486 (0.239-0.986) among females. These data strongly suggest that the mass screening program is effective in reducing stomach cancer mortality.

This report is biased on 1,139 patients with gastric cancer (GC) detected by mass screening conducted by the Center for Adult Diseases, Osaka during 1961-1985. Early GC totalled 527 patients and advanced GC totalled 6121 patients. In 859 patients curative resection was performed. Their vital status was traced yearly and six patients were lost to follow-up. Relative survival rates of screening-detected GC patients were 69-70% and almost constant after 5 years from operation/diagnosis. The survival curve in which only death from GC was counted as a death was almost equal to the relative survival curve in its shape and value. The hazard rates of screening detected GC patients decreased rapidly within 7 years and remained low affter 7 years. It was confirmed by this long-term follow-up study that about two thirds of GC patients detected by screening were successfully cured of their disease. Cancer 63:613-617, 1989. N JAPAN mass screening for stomach cancer has been I carried out for over 25 years mainly with photofluo-rographic radiography, and 5.2 million people were examined in 1985. The main purpose of this screening is to detect as many curable gastric cancers (GC) as possible in the asymptomatic phase:, and to reduce the number of deaths from GC. In order to evaluate this screening program , it is necessary to follow up the detected GC patients for a long period and to know their prognosis. At the Department of Mass Examination for Stomach Cancer in the Center for .4dult Diseases, Osaka, yearly followup surveys on all screening-detected patients have been carried out and the causes of death have been investigated for dead patients. Based on the results of this survey we calculated the survival rate of GC for a 15-year period, and analyzed the causes of death by years froh operation/diagnosis. Materials and Methods The subjects of our follow-up study were a total of 1,139 GC patients detected by mass screening conducted by the Department of Mass Screening of the Center for Adult Diseases, Osaka during 196 1 to 1985. Two hundred twenty patients were detected by the examination in the detection clinic of the Center with roentgenogram taken on a full size film, and the other 919 patients were examined in automobile units mounted with the x-ray apparatus where photofluorogram was taken on a 100 mm width roll film. Table 1 shows the sex and age distribution of our study subjects which consisted of 826 men and 313 women. The major age groups of detected patients were forties, fifties, and sixties. Table 2 shows the number of study subjects by cancer type and by method of treatment. Early GC totalled 527 cases. According to the classification of the Japanese En-doscopy Society, early GC is gastric cancer, the infiltration of which is limited to the mucosa or submucosa. The majority of the early GC in Table 2, i.e., 509 cases out of 527 were confirmed as early GC by examining resected stomach. For the remaining 18 patients, however, operation had not been conducted because either they refused it or they had other diseas...

To assess the validity of mass screening tests for gastric cancer conducted with three types of radiographic techniques, i.e., photofluorography by a mirror camera, photofluorography by an image intensifier, and direct radiography, 105,122 persons who underwent a total of 272,667 screening tests during 1970 through 1982 were followed through December 31, 1983 by means of a record linkage to the Osaka Cancer Registry, Osaka, Japan. The results of 1 year's follow-up from screening were defined as the gold standard and test performance values were calculated. Sensitivity of screening with photofluorography by a mirror camera, photofluorography by an image intensifier, and direct radiography was 90%, 8970, and 91%, and specificity was 86%, 92%, and 91%, respectively. The receiver operating characteristics curve for screening with photofluorography by an image intensifier resembled that for direct radiography and these two curves were located somewhat to the left of the curve for screening with photofluorography by a mirror camera. The authors conclude that the validity of screening with photofluorography by an image intensifier is almost equivalent to that of screening with direct radiography and both are superior to that of screening with photofluorography by a mirror camera.

The mortality pattern of Koreans living in Osaka, Japan was surveyed by comparing their age-specific and age-adjusted death rates with those among Japanese during 1973-1982. Cancer was the leading cause of death among Korean males, while cerebrovascular disease was most common among Korean females in Osaka. Mortality rates from tuberculosis, cancer, mental disorder, cerebrovascular disease, chronic obstructive pulmonary diseases (COPD), liver cirrhosis, accidents and suicide were significantly higher for Korean males than for Japanese males. COPD, liver cirrhosis and accidents were more frequent for Korean females than for Japanese females. In cancers, liver cancer was most common among Korean males, followed by stomach and lung cancers. Stomach cancer was most frequent among Korean females, followed by uterine and liver cancers. The ratio of cancer mortality rates for Koreans and Japanese was significantly higher than 1.0 for oesophagus, liver and lung among males, and for liver among females. Koreans had considerably higher levels of liver cancer and liver cirrhosis compared with Japanese. Mortality from stomach cancer was significantly lower in both sexes among Koreans in Osaka and the reduction of this disease among Koreans in Japan occurred more rapidly than among Japanese.

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