[Investigation into mediastinal lymph node metastasis of lung cancer and rationale for decision of the extent of mediastinal dissection].

UNLABELLED

From the study on the regional lymphatic drainage and investigation into mediastinal lymph node metastasis of lung cancer, we have decided the extent of mediastinal dissection as follows; 1) For right lung cancer, as the routine procedure, extended systematic ipsilateral mediastinal dissection including the left tracheobronchial region, the anterior and the posterior ipsilateral mediastinum through a conventional thoracotomy. 2) For left lung cancer, as the routine procedure, systematic bilateral mediastinal dissection through a median sternotomy. 3) For the patients with advanced lymph node metastasis (the highest mediastinal or the cervical node involvement) or direct extension into the upper mediastinum of cancer in any side of the lungs, the lower half of modified radical neck dissection combined with systematic bilateral mediastinal dissection through a cervical collar incision and median sternotomy.

RESULTS

1. The noteworthy location and incidences of mediastinal lymph node involvement were as follows; 1) Among 34 patients of right lung cancer with pN2-3 M0 disease, in 5 patients the anterior mediastinal node involvement and in 6 patients (18%) the contralateral tracheobronchial node involvement were found by the pathological investigation at surgery. 2) The incidences of contralateral mediastinal node involvement at median sternotomies were 20% of 15 patients of the left upper lobe primary and 57% of 7 patients of the left lower lobe primary. 2. Postoperative survival rates calculated with Kaplan-Meier method; 1) The five-year survival rates were 67% in 22 patients with pT1-2N2M0; 72% in 20 patients with pT1-2N2-3 alpha (one level) M0 and 65% in 13 patients with pT1-2N2-3 alpha (multi level) M0. 2) The five-year survival rate of 8 patients with N3 gamma whose cancer were diagnosed as cN0-3 alpha preoperatively and resected completely was 60%. In conclusion, these results encourage us to continue this study because we can believe that our systematic mediastinal dissection beyond the anatomical difficulties would bring better prognoses in the patients with pN2-3 disease.