Clinical predictors of N2 disease in the setting of a negative computed tomographic scan in patients with lung cancer.

OBJECTIVES: Although preoperative cervical mediastinoscopy is absolutely indicated for patients with lung cancer in whom computed tomography demonstrates mediastinal nodal enlargement, the indications when the computed tomographic scan is negative are controversial. To determine the indications in patients with negative computed tomographic scans, we retrospectively studied patients with surgically resected lung cancer.
METHODS: Between 1992 and 1997, 379 patients with lung cancer who had clinical N0-1 disease underwent surgical resection of lung cancer. Mediastinal lymph nodes were pathologically examined for metastasis in all the patients. A clinical diagnosis of nodal involvement was determined on the basis of preoperative computed tomographic findings: that is, mediastinal or hilar lymph nodes 1.0 cm or larger in the shortest axis were diagnosed as metastatic. Univariate and multivariate analyses were performed to determine the relationships between 9 clinical factors and pathologically proven N2 disease.
RESULTS: Among the patients with clinical N0-1 disease, 68 (17.9%) had pathologic N2 disease. Adenocarcinoma histology, large tumor dimension, and high serum carcinoembryonic antigen levels were significant predictors of pathologic N2 disease on the basis of multivariate analyses (P <.05). When these factors were combined, 43% of adenocarcinomas larger than 2.0 cm with high serum carcinoembryonic antigen levels (P <.001), 34.7% of adenocarcinomas with high serum carcinoembryonic antigen levels (P <.001), 25.6% of adenocarcinomas larger than 2.0 cm (P =.009), and 31.1% of patients with high serum carcinoembryonic antigen levels and large tumor dimension (P <.001) had pathologic N2 disease.
CONCLUSION: Preoperative cervical mediastinoscopy should be considered in patients in whom computed tomography is negative for lung cancer and who have some pathologic N2 predictive factors.