Background and study aims: Invasive carcinoma is found at histology in 2-5% of colorectal polyps removed under flexible endoscopy. The aim of this study was to confirm that histologically complete endoscopic polypectomy under favorable low-risk conditions is sufficient therapy for pT1 carcinoma, while tumors at or close to the margin of the polypectomy, and histological high-risk criteria, require surgical resection with lymphadenectomy.
Patients and methods: Eighty-six patients with 87 pT1 carcinomas underwent polypectomy within a twelve-and-a-half-year period. Further treatment prospectively followed the above guidelines. The follow-up was documented.
Results: A local tumor residue was found in 5 of 34 patients who had undergone surgical resection for doubtful or incomplete polypectomy. Two patients were found to have nodal disease in the surgical specimen, only one of them harboring a high-risk carcinoma. Two further patients with high-risk carcinomas had tumor progression, despite postpolypectomy resections without local tumor residue or lymph-node infiltration, and died. One patient had a local tumor recurrence on follow-up endoscopy eight weeks after doubtfully complete polypectomy. He underwent resection, and had no further recurrence. No further manifestations of invasive carcinoma occurred after complete polypectomy of 42 patients with low-risk carcinomas.
Conclusions: This study supports the view that complete endoscopic polypectomy is an adequate therapy for low-risk carcinoma: A modification of the follow-up regimen, with less frequent endoscopic controls, is justified.