Laparoscopic colorectal cancer resection: examining lymph nodes or standardizing surgery?

Abstract

There is now debate about how many lymph nodes should be dissected during colorectal cancer (CRC) by surgery and subsequently retrieved from the specimen and examined by pathologists. Appropriate lymphadenectomy is crucial for the patient’s oncological outcome for two reasons. First, it reduces the risk of residual nodal disease, and second, examination of only a large number of lymph nodes allows for accurate nodal staging. The pathological tumor-nodemetastasis (pTNM) staging by examining a sufficient number of lymph nodes allows an accurate estimation of the ratio between positive and total number of lymph nodes evaluated. This global nodal status information is necessary for making a decision about adjuvant systemic chemotherapy. Recent guidelines from scientific associations and organizations, including the American College of Surgeons (ACS), the National Quality Forum (NQF), the National Comprehensive Cancer Network (NCCN), and the American Society for Clinical Oncology (ASCO), recommend that a minimum of 12 lymph nodes should be removed and histopathologically examined for appropriate treatment of patients with CRC [1]. However, two large retrospective studies question this strategy. Based on a retrospective analysis of the national Surveillance, Epidemiology, and End Results (SEER) Medicare-linked database (19952005) of patients in the U.S. (n = 30625) who underwent colectomy for nonmetastatic colon cancer, Wong et al. [2] came to the provocative conclusion that ‘‘Efforts by payers and professional organizations to increase node examination rates may have limited value as a public health intervention.’’ In another more recent retrospective analysis of 24,477 stage III colon cancer patients identified from the SEER cancer registry, Wang et al. [3] found that the total number of lymph nodes examined is not a reliable prognostic factor for stage III colon cancer. How many lymph nodes should be removed in laparoscopic CRC surgery? This question is relevant because laparoscopic resection has been increasingly used in dayto-day clinical practice not only for CRC but also other gastrointestinal cancers [4–8]. In a current review [9] and an international survey of surgeons about laparoscopic rectal surgery [10] it was found that there was more emphasis on the optimal extent of surgery rather than the number of lymph nodes retrieved. Indeed, most surgeons in the European Association for Endoscopic Surgery (EAES), the Indian Association of Gastrointestinal Endo-Surgeons (IAGES), and the Society of Laparoscopic Surgeons (SLS) and renowned surgeons who perform laparoscopic total mesorectal excision (LTME) agreed on the necessity and utility of standardized laparoscopic surgery. For example, standardization of the highly demanding laparoscopic low anterior resection with high ligation of the inferior mesenteric artery at its origin, splenic flexure mobilization, and TME with safety distal resection margins of at least 2 cm provides the greatest possibility for the good oncological and quality-of-life outcomes [9, 10]. In the January 2010 issue of this journal, El-Gazzaz et al. [11] added important information on laparoscopic CRC surgery. The authors emphasized assessing the number of lymph nodes dissected during surgery and examined by the pathologists after laparoscopic or open surgery. The authors compared 243 patients who underwent laparoscopic surgery C. Hottenrott (&) Chirurgische Klinik, St. Elisabethenkrankenhaus, Ginnheimer Strase 3, 60487 Frankfurt, Germany e-mail: info@gastricbreastcancer.com