RADIOIMMUNOGUIDED SURGERY FOR COLORECTAL-CANCER

Background: Operations for patients with colorectal cancer are based o n traditions established by historical experience. Radioimmunoguided s urgery (RIGS) provides new information that challenges these tradition s. Methods: Thirty-two patients with primary colorectal cancer underwe nt RIGS after being injected with anti-TAG-72 murine monoclonal antibo dy CC49 labeled with iodine-125. Sixteen of the patients had all gross tumor and RIGS-positive tissue removed (RIGS-negative group), and 16 had only traditional extirpation of the tumor because RIGS-positive ti ssue was too diffuse (RIGS-positive group).Results: In the 16 patients having all RIGS-positive tissue removed, five had traditional regiona l en bloc resections and 11 had additional extraregional tissues resec ted. Identification of extraregional disease added two liver resection s and 25 lymphadenectomies: 10 of the gastrohepatic ligament, five cel iac axis, six retroperitoneal, and four iliac. With a median follow-up of 37 months, survival in the RIGS-negative group is 100%. In 14 of 1 6 patients (87.5%) there is no evidence of disease. In the RIGS-positi ve group, follow-up shows 14 of 16 patients are dead and two are alive with disease (p < 0.0001). Conclusion: These results suggest that RIG S identifies patterns of disease dissemination different from those id entified by traditional staging techniques, Removal of additional RIGS -positive tissues in nontraditional areas may improve survival.