PREOPERATIVE STAGING OF RECTAL AND COLONIC-CANCER

In rectal cancer, endosonography assesses the tumor penetration depth, EUS T1 to EUS T3, with a sensitivity of 96 % and a specificity of 89 %. The evaluation of lymph nodes is less accurate, at 79 %. The surgic al strategy is different in the three parts of the rectum, and depends on the endosonographic tumor stage: upper third of the rectum - anter ior resection for all tumor stages; middle third of the rectum - EUS T 1 N0: transanal endoscopic microsurgery for ''low-risk'' carcinomas; E US T1-2: anterior resection; EUS T3: anterior resection with complete excision of the mesorectum, reconstruction with coloanal pouch; lower third of the rectum - EUS T1 N0: transanal endoscopic microsurgery for ''low-risk'' carcinomas; EUS T1-2: anterior or intersphincteric resec tion with complete excision of the mesorectum, reconstruction with col on pouch; EUS T3: abdominoperineal excision. With the impact of endoso nography, the proportion of abdominoperineal excisions has dropped fro m 46 % to 15 % during the last five years. Laparoscopic technology is likely to have an increasing impact on surgical procedures that have p reviously required an open approach. The following treatment policy de rived from the endosonographic staging of colon tumors is proposed: EU S T1, laparoscopic segmental resection; EUS T2, laparoscopic oncologic al resection; EUS T3, conventional open surgery.