Does nodal status influence survival? Results of a 19-year systematic lymphadenectomy experience during lung metastasectomy of colorectal cancer

OBJECTIVES Resection of pulmonary metastases originating from colorectal cancer is increasingly considered. While several adverse risk factors for long-term outcome are known, the selection of patients who may benefit from surgery remains unclear. In particular, few studies have addressed the impact of lymph node involvement, and signification of the hilar or mediastinal level of extent. METHODS We retrospectively reviewed the data of 320 patients operated in two thoracic departments between 1992 and 2011. Appropriate statistical tests were used to compare groups at risk. RESULTS There were 105 women and 215 men with a mean age of 63.3 years (range: 27-86) at the time of metastasectomy. Lymph node involvement appeared as a significant prognostic factor in both the univariate and multivariate analyses [median survival: 94 months N0 vs 42 months N+, P < 0.0001; OR = 0.573 (0.329-1), P = 0.05]. Survival was similar for hilar and mediastinal locations (median survival: 47 months vs 37 months, respectively, P = 0.14). Associated hepatic metastases had a negative impact on survival in both univariate and multivariate analyses [median survival: 74 months vs 47 months, P < 0.01; OR = 0.387 (0.218-0.686), P = 0.001]. Multiple lung metastases significantly decreased survival in univariate analysis only (median survival: 81 months vs 55 months, P < 0.01). Disease-free survival and preoperative carcinoembryonic antigen had no impact on survival. CONCLUSIONS While lymph node involvement was associated with decreased survival, the impact of mediastinal location on survival did not differ from that of hilar location. Consequently, these patients should not be excluded from surgical treatment.