Significance of positive superior mediastinal nodes identified at mediastinoscopy in patients with resectable cancer of the lung

Abstract

The prognosis for resectable lung cancer with metastases in mediastinal nodes is not clear. There are 12 papers reporting results in such cases, and the 5 year survival figures range from 0% to 30%. During the past 17 years at Toronto General Hospital, 141 patients had a thoracotomy for presumably operable, non-oat cell lung cancer with metastases in mediastinal nodes. Group 1, those with “mediastinoscopy positive” nodes, comprised 79 cases. This is a highly selected subset of patients with presumably operable lung cancer who had ipsilateral superior mediastinal metastases identified by mediastinoscopy, and in whom a curative resection was deemed possible. This subset represents only one fifth of our patients with presumably operable lung cancer in whom N2 status is defined at mediastinoscopy. The actuarial 5 year survival rate for all 79 patients was 9%. The 5 year survival rate in 51 curative resections was 15%, and no patient having a palliative resection survived 5 years. Group 2, those with “mediastinoscopy negative” nodes (N2 status determined at thoracotomy) comprised 62 cases. All 62 patients had negative mediastinoscopy, and the N2 status was established only at subsequent thoracotomy. The actuarial 5 year survival rate was 24% for all 62 patients, 41% for the 25 curative resections and 14% for the 22 palliative resections. The survival rate is significantly worse in those patients whose N2 status is established at mediastinoscopy than in those patients with a “negative mediastinoscopy” in whom the N2 status is established at subsequent thoracotomy. The application of mediastinoscopy in the selection of operable N2 lesions is emphasized.