linitis plastica型胃癌と胃底腺領域癌の年代的推移―集検受診群と病院受診群を対比して

The Time Trend of Linitis Plastica Type Cancers and Cancers in the Gastric Body: Comparison between Mass Screening and Non-screening Groups

要旨　linitis plastica型胃癌（以下，LP型癌）と胃底腺領域癌を，集検受診群と病院受診群に分け，15年間の推移を比較検討した．LP型癌の年代的な数は，集検・病院群ともに変化なかったが，発見胃癌に対する割合は，集検群において漸減していた．男女間では両群ともに女性に多かった．LP型癌の平均年齢は，集検群の男性を除き，胃癌全体に比し4～6歳若かった．胃底腺領域癌の年代的な数，頻度は，両群間に差がなかった．発見胃癌に対する割合は，集検群平均12.8％，病院群平均9.8％であった．進行度別にみると，両群とも進行癌が減少し，早期癌が増加していた．女性に多く，平均年齢ではLP型癌と同じ傾向であった．LP型癌の予後は，5年累積生存率で，集検群9.5％，病院群8.1％と差がなかった．

　The time trend of linitis plastica type gastric cancers (LPGC) and cancers in the gastric body (CGB) was examined for mass screening and non-screening groups. The survey period was divided into three: Ⅰ (1976～1980), Ⅱ (1981～1985) and Ⅲ (1986～1990).

　The number of LPGC was 40 in the screening group (Ⅰ; 11, Ⅱ; 15, Ⅲ; 14), and 101 in the non-screening group (Ⅰ; 31, Ⅱ; 36, Ⅲ; 34). The number of LPGC was not significantly different between two groups. However, the ratio of the LPGC to the total of the gastric cancers in the screening group gradually decreased with the passage of the periods: Ⅰ; 6.3%, Ⅱ; 5.0%, Ⅲ; 3.7%. As for sex and age, women outnumbered men in both groups, and except for men in the screening group, the mean age of LPGC patients was four to six years younger than that of the total of gastric cancer patients There was no difference between the two groups in five-year survival rate of LPGC (screening group; 9.5%, non-screening group; 8.1%).

　The number of CGB was 109 in the screening group (Ⅰ; 22, Ⅱ; 44, Ⅲ; 43), and 188 in the non-screening group (Ⅰ; 63, Ⅱ; 59, Ⅲ; 66). Though the number and the ratio were stationary in both groups, the ratio of CGB to the total of gastric cancers of the screening group (12.8%) was higher than that of the non-screening group (9.8%). The differences in sex and age were similar to those of LPGC. In addition, the ratio of early to advanced cancers of CGB gradually increased with the passage of periods.