The safe and effective use of postoperative radiation therapy in modified Astler Coller Stage C3 rectal cancer.
Locoregional recurrence in patients with Stage C3 (adjacent organ invasion) rectal carcinoma approaches 100% when surgery is not followed by adjuvant radiation therapy. The advent of the intestinal sling procedure (use of an absorbable polyglycolic acid mesh to suspend the small bowel out of the pelvis) has allowed tumoricidal doses (5000 cGy) of radiation therapy to be delivered to the pelvis without incurring radiation associated small bowel injury (RASBI). This surgical technique has allowed us to readdress the question, "what is the effectiveness of postoperative radiation therapy when tumoricidal doses can be safely administered to patients with Stage C3 rectal cancer?" Nineteen consecutive patients with Stage C3 rectal carcinoma underwent resective procedures and simultaneous use of the intestinal sling procedure. Postoperatively, all patients underwent contrast simulation studies that documented the small bowel above the sacral promentory. Tumoricidal doses ranging from 5200 to 5800 cGy (mean, 5600 cGy) were administered in fractionated doses. No patient demonstrated obstruction, infection, nausea, vomiting, cramps, diarrhea, or acute RASBI. There have been two locoregional recurrences in a mean follow-up period of 33 months (range, 12 to 54 months) in patients evaluated by physical examination, carcinoembryonic antigen (CEA) levels, computed axial tomography (CAT) scans, endoscopy, and reoperation or autopsy (P = 0.01). There have been ten distant recurrences (eight liver, one brain, and one lung). Three patients were reoperated on to rule out recurrence at 16, 17, and 24 months. All mesh was resorbed and there were no adhesions and no recurrent tumor. When the intestinal sling procedure is used, tumoricidal doses of radiation therapy can be safely administered without incurring RASBI. Postoperative high-dose radiation therapy can suppress locoregional recurrences in Stage C3 rectal carcinomas over and above what would be expected.