[Large bowel cancer: prognostic factors, surgical treatments and their results]

Although the classification proposed by Dukes has been repeatedly modified, causing unnecessary confusion, his original concept remains unrefuted; cancer penetration through the bowel wall and lymph node metastasis are two major prognostic factors, of which nodal metastasis represents a more advanced stage. However, the results of our exhaustive computer analyses did not support this concept, and better classifications may be developed using our computer algorithm, enabling us to refine the indication for extensive surgery or limited resection. There are two trends of surgical treatment in Japan. One is an attempt to extend the area of resection including the paraaortic and parailiac nodes, and also iliac vessels. Patients treated by this method show a higher survival rate if compared with historical controls in Japan. However, extensive surgery of the rectum is associated with poor quality of life with bladder and anal dysfunctions as well as sexual impotence. The other trend is to limit the extent of resection and minimize the functional defect. The organs thus saved include the sphincter and autonomic nerves. The results are almost comparable with those of more radical surgery. With aggressive re-resection of recurrent tumors in the liver, lungs, lymph nodes and local areas, the number of long-term survivors is now increasing who would otherwise have died.