Role of cervical mediastinoscopy in staging of non-small cell lung cancer without enlarged mediastinal lymph nodes on CT scan.

Abstract

The results of primary surgery for non-small cell lung cancer (NSCLC) with involved ipsilateral mediastinal or subcarinal lymph nodes (N2 disease) remains poor. However, several studies suggest that induction chemotherapy could increase long-term survival in patients with N2 disease. Therefore, accurate preoperative staging of the mediastinum remains of paramount importance for the treatment policy in patients with NSCLC. Enlarged mediastinal lymph nodes (MLN) on CT scan are positive in only half of the patients. Small lymph nodes can contain metastatic deposits of clinical importance. However, many surgeons believe that a normal mediastinum at computed tomography allows them to cancel their preoperative mediastinal exploration. It was the aim of this study to evaluate the results of cervical mediastinoscopy in patients without enlarged MLN on CT scan. Between January 1990 and June 1994, 235 patients with potentially operable NSCLC underwent a cervical mediastinoscopy despite the absence of enlarged MLN on CT scan. MLN were considered enlarged if they were equal to or larger than 15 mm at their maximal cross-sectional diameter. Cervical mediastinoscopy was positive in 47 patients (20%). In 21 patients, N2 disease was extranodal and in 16 patients more than one level was involved. Mediastinoscopy was positive in 9.5% of the cT1N0 cases, in 17.7% of the cT2N0 lesions, in 31.2 and 33.3% of cT3N0 or cT4N0 tumors, respectively. After a negative cervical mediastinoscopy, resectability for unforeseen N2 disease was as high as 95%. We recommend a cervical mediastinoscopy in every patient with potentially operable NSCLC.