Lateral pelvic lymph-node dissection: still an option for cure

Abstract

114 www.thelancet.com/oncology Vol 11 February 2010 We read with great interest the article “Extended lymphadenectomy versus conventional surgery for rectal cancer: a meta-analysis” by Georgiou and colleagues in The Lancet Oncology. However, we have to disagree with the methodology and conclusions. The title of the paper suggests that the authors did a meta-analysis and concluded that extended lymphadenectomy does not confer a signifi cant oncological advantage, and is associated with increased genito-urinary dysfunction, compared with conventional surgery. However, there are some fundamental problems with the methods used which result in some misleading conclusions. The main issue revolves around the validity of doing a meta-analysis on disparate groups. With the exception of the single small randomised study, the extended lymphadenectomy group undoubtedly had more advanced tumours—ie, larger (higher T stage), nodepositive, and more aggressive pathology—compared with the non-extended lymphadenectomy group. Therefore, one cannot “meta-analyse” these entirely diff erent groups. In fact we would interpret the results as the exact opposite to the authors’ conclusion: the extended lymphadenectomy group benefi ted substantially, as the survival and local recurrence were the same despite the more advanced nature of the disease. Furthermore, the time period of this review is very long (1984–2007). Over the past two decades, as Moriya argued in his article in the same issue of The Lancet Oncology, there have been substantial changes in the Japanese approach to treating rectal cancer in terms of indication criteria and the techniques used. Extended lymphadenectomy for upper rectal cancer has practically been abandoned, and Japanese surgeons are far more selective in the indications for extended lymphadenectomy using meticulous analysis of their experiences, and outcomes, and using modern imaging techniques. Additionally, nerve-sparing techniques have recently been developed and refi ned with markedly improved function. Based on a large recent multicentre study and other reports, we strongly believe that recent refi nements and optimal extended lymphadenectomy might be benefi cial to selected patients, particularly with low rectal cancer, and perhaps equivalent or better than pre-operative chemoradiotherapy and standard total mesorectal excision. The misinterpretation of the data in Lateral pelvic lymph-node dissection: still an option for cure