[Impact of systematic lymph node dissection in the resection of pulmonary metastases of solid extrapulmonary tumours]

The systematic mediastinal and hilar lymph node dissection for the treatment of pulmonary metastases has, until now, not attracted much attention. A possible advantage of systematic lymph node dissection is an improved staging and a better locoregional tumour control due to resection of tumour micrometastases and the disintegration of lymphatic vessels. Aim of the study was to investigate the impact of mediastinal and hilar lymphnode metastases on the prognosis of the patient.

Between 1978 and 2006, 249  patients underwent resection of pulmonary metastases from renal cell (91), colorectal (89), breast (45) and head and neck cancer (24), in combination with a systematic mediastinal and hilar lymphnode dissection. Survival was analysed by the Kaplan-Meier method. Multivariate analysis was performed using Cox regression analysis. Lymph node metastases were histologically demonstrated in 25.3 % of all patients. They did not correlate with the tumour grading and lymph node status of the primary tumour or the number of pulmonary metastases. Patients with lymph node metastases had a significantly shorter median survival than patients without (18 vs. 53  months, p < 0.001). Patients who underwent a systematic mediastinal and hilar lymph node dissection showed a trend to a prolonged survival (39.1 vs. 31.9  months, p = 0.089).

Mediastinal and hilar lymph node metastases are significantly correlated with decreased survival. Systematic mediastinal and hilar lymphadenectomy provides valuable information for the staging and prognosis of patients with pulmonary metastases of kidney, head and neck, breast and colorectal cancers and may help to distinguish those patients who might profit from a more aggressive surgical therapy or an adjuvant therapy.