Strong evidence in favor of complete mesocolic excision

During the last several years debate has continued as to the potential merits of complete mesocolic excision (CME) for the attempted curative treatment of colorectal carcinoma. While numerous studies have found the technique to confer oncologic benefit others publications have reached conclusions that other studies have failed to identify such benefits. Bertelsen and coworkers on behalf of the Danish Colorectal Cancer Group published their article “Disease-free survival after complete mesocolic excision compared with conventional colon cancer surgery: a retrospective, population-based study” in The Lancet Oncology. Specifically, the authors retrospectively compared the data for all patients who underwent elective resection for stage I, II or III adenocarcinomas in 4 hospitals in the vicinity of Copenhagen, Denmark. 1,031 patients underwent standard traditional surgery while 364 patients had CME performed. The groups were very well stratified for gender, BMI, ASA score, tumor location and size, organ resection, and 30-day mortality. The groups were also well matched for tumor stage and PT level. However, there were very significant differences between the groups in terms of the number of lymph nodes resected being a mean of 36.5 in the CME group as compared to only 10 in the non-CME group. Similar differences existed relative to the median numbers of 34 and 19, respectively. Furthermore, while 99% of the specimen retrieved by CME technique included ≥12 lymph nodes only 89% of specimens in the non-CME group fulfill this minimum criterion. Similarly, the mean number of lymph node metastasis in the CME group was 2.2 as compared to 1.3 in the non-CME group. There were higher incidences of serosal invasion and extramural venous invasion in the CME group although there no such differences relative to perineural invasion. The authors found four year disease free survival of 85.8% following CME as compared to only 75.9% after non-CME surgery. When the valuation was performed by stage patients with UICC stage I disease who had undergone CME appreciated a 100% survival as compared to only 88.98% in the non-CME group. The data for UICC stage II patients was similarly 91.9% versus 77.9%. And lastly, in the UICC stage III group the results were 73.5% and 67.5%, respectively. The authors performed a multivariable Cox regression analysis which showed that CME surgery was an independent and significant prognosticator for improved disease free survival for all patients. Even after propensity score matching this result held true. The authors concluded that CME surgery was associated with better disease free survival than was conventional surgery. I applaud the authors for producing such a high quality large retrospective database study which very elegantly demonstrates the benefits of CME. I look forward to reviewing and participating in future such studies ideally as randomized controlled trials which will definitively answer this question.