Surgery versus endoscopic resection for malignant colorectal polyps

The present study compared outcomes of two treatment methods for patients with malignant colorectal polyps (MCP): endoscopic versus surgical management.

Most colorectal cancers develop from a malignant (cancerous) polyp, an abnormal growth on the inner surface of the large intestine. When a polyp is found, the only way to know if it is cancerous or not is to remove it completely or part of it (biopsy) and to have it analyzed by a pathologist. Removal of a polyp can be done either surgically, by removing the section of the colon which contains the polyp (colectomy), or during a colonoscopy (endoscopy), by cutting the polyp (polypectomy). A colonoscopy is a procedure doctors use to look inside the large intestine using a thin flexible tube with a camera (colonoscope). A MCP is considered stage I colorectal cancer, thus management of these lesions need careful analysis and patients must be closely monitored. 

The present study included 386 patients with MCP. 165 patients (42.7%) were diagnosed through a biopsy, with no attempt to remove the polyp and 221 patients (57.3%) were diagnosed when the polyp was removed during a colonoscopy. All the patients diagnosed via biopsy had surgery to remove the MCP thereafter. Out of the patients managed endoscopically, 103 (46.6%) received follow-up surgery, of whom 76.7% had no residual cancer. Of the remaining 118 patients (53.4%) in the endoscopy group, none (100%) had residual cancer on follow-up colonoscopy. There was no significant difference among overall survival (defined as the percentage of patients who have survived for a certain period of time) after surgical or endoscopic management of MCP. 

In summary, endoscopic management appears to be safe and effective in a selected group of patients with MCP, with survival outcomes comparable with patients treated surgically. 

The study had a short follow up period (approximately 2 years) which might be insufficient to determine the recurrence (return of the cancer) rate. Also, the study looks back at patients who have been treated in the past (retrospective study) rather than following the patients throughout their treatment and determining their outcomes (prospective study). Retrospective studies are considered to provide weak statistical evidence.