[in Japanese]

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[in Japanese]

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The purpose of this study is to detect any factors affecting proper diagnosis in indirect photofluorography for gastric cancer screening. Gastric cancers detected in mass screening were categorized as either true positive (n=96) or false negative (n=28) cases. We compared the differences between the two groups with reference to the following items: locations, sizes of long diameter, depths of invasion, shape types, and histological types.
Lesions located on the lesser curvature in the U region, with a diameter shorter than 10 millimeters, with mucosal invasion, and of flat shape were strongly associated with incorrect check-up results. In fact, 76.9% of the false negative cases were not identified through indirect photofluorography. Especially in the U region, most cases including two advanced cancers were not recognized. The results demonstrate that the improvement of the photographic procedures is more important than the improvement of the photograph-reading capability in indirect photofluorography. In order to avoid missing gastric lesions, the use of a concentrated contrast material is required for revealing small abnormalities. And a fully worked-out rolling manipulation of patients during examination should also be considered, so as to obtain fine photofluorographies without leaving any blind spots.

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Based on the 206 cases of colorectal cancer we have encountered during the past seven years, we have evaluated the usefulness of testing for occult blood in feces in the screening of colorectal cancers; we have also evaluated the sensitivity of colonoscopy in the detection of colorectal neoplasm. These 206 cases of colorectal cancer were divided into 2 groups: the asymptomatic group (145 cases) and the symptomatic group (61 cases). Ninety six per cent of the asymptomatic group had positive occult blood in feces. The asymptomatic group had early cancers in 85% of the cases (mucosal invasion: 55%; submucosal invasion: 30%) or Dukes A lesions in 87%, and received endoscopic resection in 64%, whereas the symptomatic group had advanced cancers in 72% of the cases, Dukes C lesions in 38%, or were inoperable in 11%, and received surgical resection in 69%. Of 750 cases in which a total of 1,406 lesions had received endoscopic resection, the initial colonoscopy done elsewhere had overlooked 60 lesions (4.3%) of over 5mm in size. Of these, 7 lesions were of over 1cm in size and 2 (other than the previous 7) were early cancers. The overlooked lesions were mostly smaller than 1 cm and of flat shape, and were often found in the sigmoid and ascending colon, but the highest rate (12.8%) of overlooking was noted in the cecum. Of 57 cases of early cancer, 23 cases (40.3%), including 3 submucosal cancers, could not be correctly diagnosed as malignancy through endoscopic biopsy done elsewhere prior to endoscopic resection. These results suggest that testing for occult blood in feces is very useful for the screening of colorectal cancer in its curable stage and that colonoscopy should be performed very carefully because it is not perfect, despite the fact that it is considered to be the most excellent method of detecting colorectal neoplasm.

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The risk of individuals who had a previous history of normal findings in diagnostic examinations using total colonoscopy to be newly diagnosed with early colorectal cancer or adenoma in colorectal cancer screening was assessed. The odds ratio was calculated using a logistic regression model, for individuals with early colorectal cancer or adenoma as a case group and others with normal findings as a control group. The past history of a normal colonoscopy result was sought in a database for mass screening programs at the workplace and was considered as the exposure factor. The odds ratios for early cancer detection within 1, 2, and 3 years were 0.17 (95% confidence interval: 0.04-0.70), 0.13 (95% confidence interval: 0.04-0.42), and 0.10 (95% confidence interval: 0.03-0.31), respectively. This suggests that the risk of an individual with a history of diagnostic examination within the previous 1 to 3 years for being newly diagnosed with early cancer is reduced by 83 to 90%, as compared with an individual with no such history. The odds ratio was lowest for within 3 years, which indicated that false negative cases in the previous examinations were included in the analysis. If the detection of early or more advanced cancer is defined as an objective of the mass screening programs, an individual who has had a normal colonoscopic examination result should take part in mass screening tests every two to three years. To achieve this goal, however, the accuracy of colonoscopy should be evaluated more strictly on a clinical basis.

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Large scale personal individualized colorectal cancer screening was undertaken in Omiya City from 1993 to 2000 and as a result 165 cases were found to have advanced cancers. The examinees count 67, 684 in total, the male to female ratio being 1:2. Of the 165 cancer cases, 88 were male and 77 were female, not indicating as much sex-related difference as in cases of early cancer. From this analysis the following tendencies and facts are noteworthy. [Age of Examinees] In view of the positive predicting value of the initial screening, effectiveness of the screening undertaken was considered high enough for the males above 55 years and for the females above 50 years. The effectiveness was questionable for the females below 49 years. [Inter-screening Interval] As far as advanced cancer is concerned, in 82.2% of the screening for colorectal cancer repeaters, it was detected within 2 years of the first screening, that is either by annual screening in males above 55 years and in females above 50 years, or even by alternative year screening for the younger age without many failures of detection. [Points of Note] Regardless the number of the experienced screening for colorectal cancer, in as many cases as 146 or 88.5% of all, cancer was detected by the first experienced screening. Furthermore, in 119 cases or 72.1% of all, the fecal hemoglobin level was above 1000ng/ml. Therefore, those examinees in such categories as mentioned herewith should be aware of their higher cancer predicting likelihood.

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The immunological test for occult blood in feces is recognized as an effective means of detecting colorectal cancers, and has been used for community and workplace mass screenings. However, fewer detailed examinations than recommended are actually performed, which presents a problem, and this tendency is felt particularly with the workplace mass screenings. In order to increase the rate of detailed examinations, we analyzed the results of the immunological tests for occult blood in feces in order to identify any high-risk group for colorectal cancer. We conducted immunological tests for occult blood in feces (twice-sampling method) on 73,955 people who underwent mass screenings for colorectal cancer in our facility in 1999 through 2001. The results showed that 52% of advanced cancer cases and 54% of early cancer (submucosal invasion) cases had a high total value of occult blood in feces: 1500ng/ml or more. This level is significantly different from that of early cancer (mucosal invasion) cases and other benign diseases (p<0.05). In cases with a test value of 1500ng/ml or more, the ratio of positive reactions indicating colorectal cancer was 11.7%. The number of cases of colorectal cancer detected in males was 1.5 times greater than the number detected in females. The rate of detection for people aged 45 or older was increasing with age. However, the rate of detailed screenings only increased for patients aged 60 or older. Consequently, we believe that cases in which the patient is aged 45 or older, and for which the total value as obtained by means of the immunological test for occult blood in feces (twice-sampling method) is 1500ng/ml or higher, should be included in the high-risk group. We are strongly advising these patients to undergo detailed examinations from 2003 onwards.

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The purpose of this study was to investigate the characteris-tics of early gastric cancer in the elderly. From 1991 to 2000, 682 patients with early gastric cancer were treated by endo-scopic mucosal resection (EMR) or surgery at our hospital. We divided the patients into three groups (adult below 65 years old, elderly, and very elderly), and compared the resultsretrospectively.
In elderly patients, there was an increase of well differentia-ted adenocarcinoma and a decrease of IIc tumors. The tumor size, depth, ly, and v were all more advanced than in the young patients. Elderly patients tend to be diagnosed in clinics or hospitals rather than by health screening. Our study sugges-ted that it is difficult to detect early gastric cancer in elderly people on the basis of current health surveillance programs.
Many patients visited clinics or hospitals with other complai-nts, and early gastric cancer was detected in some of them.
It is important to determine how to select patients by initial screening and how to shift the method of health surveillance from radiographic examination to endoscopic examination. Detailed health assessment may become important to perfor-m when a new elderly patient presents to a clinic.

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