Risk factors for unfavorable outcomes after endoscopic removal of submucosal invasive colorectal tumors.

BACKGROUND & AIMS: Oncologic surgery is recommended after endoscopic resection of submucosal invasive T1 colorectal carcinomas if patients are considered to be at high risk for tumor recurrence or metastasis. However, there are sparse data on the outcome of high-risk patients treated only by endoscopy.
METHODS: Data were collected from 474 patients who underwent endoscopic resection for T1 colorectal cancers from 1974-2002 at Neuperlach Hospital in Munich, Germany. Patient files were reviewed, and patients or referring physicians were contacted to assess outcomes during a follow-up period of at least 24 months (n = 390). Histopathology and endoscopy factors associated with an unfavorable outcome (local recurrence of tumors, metastasis, or death from colorectal cancer) were assessed.
RESULTS: Of the 390 patients followed, 141 received oncologic surgery, and 249 did not; overall, 10% had an unfavorable outcome (39/390). Multivariate regression analysis revealed that lymphatic vessel infiltration, poor grading of tumor stage, and incomplete endoscopic resection were risk factors for unfavorable outcomes (odds ratios, 7.8, 3.4, and 2.6, respectively). If these risk factors were applied to patients who did not receive oncologic surgery, negative predictive values for an unfavorable outcome were 94.6% for lymphatic vessel infiltration, 94.2% for poor grading of tumor stage, and 96.5% for incomplete endoscopic resection; positive predictive values were 44.4%, 42.9%, and 19.6%, respectively.
CONCLUSIONS: Tumor infiltration of lymphatic vessels is the greatest risk factor for an unfavorable outcome after endoscopic resection for colorectal carcinoma. However, its positive predictive value is low. The decision to perform surgery after endoscopic resection of T1 colorectal cancers should be made on the basis of specific features of each patient.