Các điều kiện predisposing cho các khối ung thư ruột nhỏ có thể được chia thành ba nhóm (Table 14,2): (a) rối loạn viêm như bệnh Crohn, (b) rối loạn hệ thống miễn dịch như AIDS, rối loạn suy giảm miễn dịch bẩm sinh | 195 NEOPLASMS OF THE SMALL BOWEL compared with 1 to 50 in reported series in humans. This observation might imply a connection between bile and carcinogenesis but the results were the same when the experiment was repeated in rats whose bile was surgically diverted. Predisposing Factors The predisposing conditions for small bowel neoplasms can be divided into three groups Table a inflammatory disorders such as Crohn s disease b disorders of the immune system such as AIDS congenital immunodeficiency disorders or patients receiving immunosuppressive therapy and c genetic disorders such as familial adenomatous polyposis FAP or hereditary non-polyposis colon cancer HNPCC . Other factors including occupational hazards and lifestyle factors such as smoking or alcohol intake were investigated in two European multicenter case-control studies 11 12 . A cohort of 70 patients diagnosed with small bowel adenocarcinoma SBA during the study period 1995-1997 were compared with 2070 matched controls. Beer and spirits intake were associated with small bowel adenocarcinoma with an odds ratio OR of and 95 confidence intervals CI of . However there was no association between smoking or total alcohol intake and adenocarcinoma of the small bowel. In a second study of the same group investigators identified occupational clustering of SBA. The strongest industrial risk factors for SBA were dry cleaning manufacture of workwear mixed farming women and manufacture of motor vehicles men . A significantly increased risk of SBA was found among men employed as building caretakers OR CI to and women employed as housekeepers OR CI to general farm laborers OR CI to dockers OR CI to dry cleaners or launderers OR CI to and textile workers OR CI to . Regional Enteritis Crohn s Disease Regional enteritis or Crohn s disease is an inflammatory bowel disease that affects mainly people in their 3rd and 4th decades of
