Role Of Lymph Nodes Dissection In Lung Metastasectomy

BACKGROUND: The role of lymph node dissection in lung metastasectomy from extrapulmonary malignancies is still uncertain. The aim of this study is to define the prognostic impact of nodal status in lung metastasectomy and the incidence of unexpected lymph node involvement after mediastinal nodal dissection. METHODS: From May 1998 to October 2005 we performed 430 lung metastasectomies with curative intent. The records of all patients who underwent radical lymph node dissection or sampling were retrospectively reviewed. Survival was calculated by Kaplan-Meier method and comparison of curves by log-rank test. RESULTS: 139 pulmonary metastasectomies with lymph node dissection were performed in 124 patients (61 men, mean age 59). There were 56 wedge resections, 30 segmentectomies, 49 lobectomies and 4 penumonectomies. Mean number of resected lymph nodes was 9.3. Mean number of resected metastasis was 2. Median disease free survival since first pulmonary resection was 49 months. Lymph node involvement was documented in 20% of patients (25); 8% (10 cases) at hilar stations and 12% (15 cases) at mediastinal stations. Rate of patients with unexpected lymph node metastasis was 12% (15 cases). Overall, estimated 5-year survival was 46%; it was 57% for subjects with no lymph node metastasis, 20% and 0% in N1 and N2 disease, respectively (p=0.026). CONCLUSIONS: Rate of occult lymph node metastasis is remarkable in patients submitted to lung metastasectomy (1 out of 8 cases). Lymph node involvement heavily affects prognosis.