EComment. Lymph node dissection in pulmonary metastasectomy for colorectal cancer

Abstract

We read with great interest the article by Renaud et al. [1] regarding the effect of lymph node status on survival after lung metastasectomy of colorectal cancer. This is a retrospective study, which reports data on an impressive 320 patients over 20 years, 140 of whom had positive lymph nodes. The authors confirm that lymph node involvement is correlated with decreased survival. However, since the presence of lung metastases is synonymous with systemic disease, adjuvant therapy is mandatory irrespective of lymph node status and, thus, prognostic factors are not very important in that sense. The real questions are whether lymph node status is a contraindication to resection and, if not, whether radical mediastinal lymphadenectomy can offer a reasonable chance for cure. The authors state that neither lymph node positivity, nor the number of metastases were considered a contraindication for resection. Further, they managed to achieve a complete resection in all patients, and they suggest that the reported rather satisfactory overall survival (37 months in patients with mediastinal disease) should be interpreted as a confirmation that their strategy is successful. It is important to remember that this is a major operation performed with curative intent [2]. We can already see from the report that 35% of N0 and 33% of N+ patients were re-operated for recurrence [1]. To justify the certain detrimental effect of a thoracotomy and the loss of lung parenchyma - as well as the psychological impact of offering false hope to a patient - [2] we must be able to offer a reasonable chance for cure. Although this question may only be answered when data from randomized trials are available [3], it would be very interesting if the authors could show that they managed to prevent recurrence in a significant number of N+ patients by presenting relapse-free survival alongside overall survival. Conflict of interest: none declared