Prognostic significance of lymph node metastasis found during pulmonary metastasectomy for extrapulmonary carcinoma

Background The prognostic significance of lymph node metastasis in cancer patients is well documented. Pulmonary metastasectomy in selected patients is associated with improved survival. Little is known about the prognostic significance of lymph node metastases found during pulmonary metastasectomy for extrapulmonary carcinoma metastatic to the lung. Methods The records of all patients who underwent pulmonary metastasectomy and complete mediastinal lymph node dissection for extrapulmonary carcinomas at our institution from November 1985 through July 1999 were reviewed. Results Eight hundred eighty-three patients underwent pulmonary metastasectomy. Of these, 70 patients (7.9%) (44 men, 26 women) had concomitant complete lymphadenectomy. Median age was 64 years (range, 33 to 83 years). Median time interval between primary tumor resection and metastasectomy was 34 months (range, 0 to 188 months). Wedge excision was performed in 46 patients, lobectomy in 16, both in 7, and pneumonectomy in 1. Lymph node metastases were found in 20 patients (28.6%) and were classified as intrapulmonary or hilar (N1) in 9, mediastinal (N2) in 8, and both in 3. There were no operative deaths. Median follow-up was 6.6 years (range, 1.1 to 14.6 years). Three-year survival for patients with negative lymph nodes was 69% as compared with only 38% for those with positive lymph nodes (p< 0.001). Conclusions The presence of lymph node metastases at the time of pulmonary metastasectomy for extrapulmonary carcinoma has an adverse effect on prognosis. Complete mediastinal lymph node dissection should be considered at the time of pulmonary metastasectomy for carcinoma to improve staging and guide treatment.