Number of retrieved lymph nodes and survival in node-negative patients undergoing laparoscopic colorectal surgery for cancer

Abstract

The number of retrieved lymph nodes in colorectal cancer resection may have an impact on staging and survival. Examination of at least 12 nodes has become a quality measure for adequate surgical practice. To evaluate the impact of the number of retrieved lymph nodes in laparoscopic colorectal surgery for cancer on node-negative patients' survival. Evaluation of our prospective in-hospital collected data of patients that underwent laparoscopic surgery for curable colorectal cancer over a 5-year period. Long-term data were collected from our outpatient's clinic data and personal contact when necessary. During a 5-year period since September 2003,173 patients were operated laparoscopically for curable colorectal cancer. Of the 117 patients who were node negative, 85 node-negative patients (72%) had 12 or more evaluated lymph nodes (mean, 18.3 + 2.4), while 32 node-negative patients had less than 12 (mean, 8.3 + 6.2). Patients with fewer than 12 nodes evaluated had significantly more left-sided tumors, while patients with 12 nodes or more had more right-sided tumors. A comparison of 5-year disease free and overall Kaplan-Meier survival curves revealed no statistically significant difference between the two groups. Evaluation of less than 12 nodes may not necessarily impact patients' survival in node-negative patients undergoing laparoscopic resection for curable colorectal cancer. A lower number of nodes may be sufficient.