OUTCOMES FOLLOWING SURGERY FOR COMPLETELY REMOVED COLONIC LATERAL SPREADING LESIONS CONTAINING SUB-MUCOSAL INVASIVE CANCER

Aims Management of malignant colorectal polyps can be endoscopic or surgical but the best approach has yet to be defined since prospective data is lacking. Endoscopic mucosal resection (EMR) is the treatment of choice for large (>20 mm) lateral spreading colonic lesions (LSL) with high success rates, good safety profile and clinical and economic advantages compared with surgery. There is no data on the outcome and management of malignant LSL (M-LSL) following complete removal by piecemeal EMR. We aimed to determine if salvage surgery for M-LSL following complete EMR resection is necessary.

Methods We analyzed data from a prospectively collected database of patients who underwent EMR at three hospitals In Israel. Patients with M-LSL were identified and their surgical and pathological data was reviewed for the presence of residual neoplastic tissue and complication. The primary end-point was the presence of residual local-regional cancer.

Results Over 36 months 346 LSL in 316 patients were completely removed by EMR. 280/346 (80.1%) were removed piecemeal. All lesions had pre-EMR biopsies without invasive cancer. Endoscopically, all lesions were not suspicious for containing deep submucosal invasive cancer. For lesions removed piecemeal, the final EMR pathology showed invasive cancer in 22 patients (7.8%). After multidisciplinary meeting (MDT), 4 cases were not sent to surgery (curative resection (n=3) or high operative risk (n=1)). 18 cases were referred for surgery due to increased risk for lymph node matastasis (table 2). In all cases, 18/18 (100%) patients underwent laparoscopic oncological resection with no major complications. There was no evidence of residual cancer in the resected colons or lymph nodes in all patients.

Conclusions Colonic LSL removed by piecemeal EMR, may not require surgery even when SMIC is present in the resected EMR specimen