The Significance of Bilateral Mediastinal Lymph Node Dissection (R3) for Cancer of the Left Lung

Abstract

Since 1986, 73 patients underwent bilateral mediastinal lymph node dissection for left lung cancer in Mitsui Memorial Hospital. We examined the location, frequency, and spread of metastases to the mediastinal lymph nodes in 25 cases with histologically proven N2 or N3 and MO disease. Contralateral metastases were more frequent than ipsilateral in the highest mediastinal lymph nodes. The 5-year survival rate of the patients who underwent R3 dissection was 65%. In this calculation, deaths occurring within 30 days after surgery (2 cases) and the patients with N3α(4 cases) disease were included and those with N3γ were excluded.There was no significant difference in postoperative survival between the patients with one level metastases and multilevel metastases.Furthermore, we subtyped the patients into two groups according to the spread of mediastinal lymph nodes metastases. The patients with limited nodal involvements such as #2*, #4, #5, #6, #7, #8 and #9 were placed in the posterolateral lesion group (10 cases) and patients with extended nodal involvements such as #1, #3 or contralateral mediastinal lymph nodes were placed in the median lesion group (7 cases). There was no significant difference in postoperative survival between these two groups. Survival in patients with clinical stage I (8 cases) or II (1 case) disease who underwent R3 was favorable despite the presence of N2 or N3α nodes (100% at 5 years). However survival in clinical N2 (8 cases) or N3 (1 case) was not so good (65% at 2 years). We suggest that R3 resection through a median sternotomy should be a standard operation for patients with N2 or N3α cancer of the left lung.