Resection of non-regional lymph node metastasis in patients with colorectal cancer.

Abstract

664 Background: Approximately 20% of patients with colorectal cancer (CRC) present with metastatic disease-most commonly to the liver or lungs. Successful resection of these metastatic foci leads to significant long-term survival. Less commonly, patients present with isolated metastasis to non-regional lymph nodes (NRLN) and little is known regarding the role of resection in these patients. The primary aim of this study is to evaluate the outcomes of patients with CRC who undergo resection of NRLN metastasis. Methods: A retrospective cohort study of patients diagnosed with CRC and NRLN metastasis was performed using the Surveillance, Epidemiology, and End Results database (2004-2012). Demographic and clinical factors were compared for patients who underwent resection of NRLN metastasis and those who had not. Kaplan-Meier and log-rank analysis was used for survival analysis. Logistic regression analysis was used to assess factors associated with resection of NRLN metastasis. Results: A total of 22,848 patients presented with metastatic CRC and underwent primary tumor resection. Of these, 786 (3.4%) presented with isolated NRLN metastasis and 78 (9.9%) underwent NRLN resection. Patients who underwent resection were more likely to be male, have rectal cancers, and poorly or undifferentiated grade tumors. Median overall survival (OS) was significantly improved for patients who underwent resection compared to those who did not (36 vs. 28 months, p = 0.036). In patients with colon cancer (N = 602), median OS was 33 vs. 21 months (p = 0.042) for those who underwent resection compared to those who did not, whereas in patients with rectal cancer (N = 184), the median OS was 45 vs. 38 months (p = 0.977), respectively. In multivariate analysis, rectal cancer (OR 1.84, 95% CI 1.08 to 3.13) and poorly or undifferentiated grade tumors (OR 1.64, 95% CI 1.01 to 2.66) were associated with increased resection of NRLN. Conclusions: Resection of NRLN metastasis in patients with CRC is associated with an overall survival benefit, particularly among patients with colon cancer. Further studies are needed to identify which specific patient subgroups would best benefit from this resection strategy.