Primary Colectomy in Patients With Stage IV Colon Cancer and Unresectable Distant Metastases Improves Overall Survival: Results of a Multicentric Study

BACKGROUND: Whether patients with stage IV colon cancer and unresectable distant metastases should be managed by primary colectomy followed by chemotherapy or immediate chemotherapy without resection of the primary tumor is still controversial. OBJECTIVE: This study aimed to evaluate predictive factors associated with survival in patients with stage IV colon cancer and unresectable distant metastases. DESIGN: This large retrospective multicentric study included 6 academic hospitals. SETTINGS: This study was conducted at 6 Paris University Hospitals (Assistance Publique-Hopitaux de Paris; Saint Antoine, Henri Mondor, Ambroise Pare, Hopital Europeen Gorges Pompidou, Bichat, and Avicenne). PATIENTS: Between 1998 and 2007, 208 patients with good performance status and stage IV colon cancer with unresectable distant metastases received chemotherapy, either as initial management or after primary tumor resection. MAIN OUTCOME MEASURES: Survival was estimated by use of the Kaplan-Meier method. Factors associated with survival were tested by means of a log-rank test. Results were expressed as median values with 95% confidence intervals. Factors independently related to survival were tested using a Cox regression model adjusted for a propensity score. RESULTS: Of the 208 patients, 85 underwent colectomy before chemotherapy, whereas 123 were treated with use of primary chemotherapy with or without biotherapy. At univariate analysis, the following factors were significantly associated with survival: primary colectomy (P = .031), secondary curative surgery (P < .001), well-differentiated primary tumor (P < .001), exclusive liver metastases (P < .027), absence of need for colonic stent (P = .009), and addition of antiangiogenic (P = .001) or anti-epidermal growth factor receptor (P = .013) drugs to chemotherapy. After Cox multivariate analysis and after adjusting for the propensity score, all of these factors, with the exception of two, colonic stent and anti-epidermal growth factor receptor drug, were found to be independently associated with overall survival. LIMITATION: This study was limited by its retrospective nature. CONCLUSIONS: In a selected population of patients with colon cancer and unresectable synchronous distant metastases, immediate colectomy followed by chemotherapy in association with targeted therapy was associated with longer overall survival. This strategy appears to be the most appropriate, especially for those with good performance status, well-differentiated tumors, and synchronous liver metastases only.