Background: Current methods for detecting mediastinal lymph node involvement with non-small-cell lung cancer can be inaccurate and are often invasive and expensive.
Objective: To assess the utility of endoscopic ultrasonography, fine-needle aspiration biopsy guided by endoscopic ultrasonography, and computed tomography for the detection of metastases to the posterior mediastinal lymph nodes in non-small-cell lung cancer.
Design: Prospective preoperative evaluation of the diagnostic operating characteristics of these procedures.
Setting: Referral-based academic medical center.
Patients: 130 consecutive patients with non-small-cell lung cancer who were otherwise good surgical candidates.
Interventions: All patients had initial computed tomography of the chest; those with enlarged nodes were referred for endoscopic ultrasonography. Endoscopic ultrasonography-guided fine-needle aspiration biopsy was done on suspicious contralateral posterior mediastinal or subcarinal lymph nodes identified by ultrasonography. At surgery, lymph nodes were dissected and categorized by location and underwent histopathologic evaluation.
Results: 52 patients were ultimately enrolled in the study: Thirty-one had thoracotomy with mediastinal dissection, and 21 had tumors considered unresectable on the basis of preoperative evaluation. Ultrasonography without aspiration biopsy had an overall accuracy of 84% for predicting metastasis to lymph nodes; computed tomography had an accuracy of 49% (P < 0.025). Twenty-four patients had ultrasonography-guided aspiration biopsy; 14 of the 24 were ineligible for surgery because cytology showed malignancy. Results of surgical pathology correlated with negative aspiration cytology results in 9 of 10 patients; the one node with false-negative results contained a 2-mm focus of cancer. The accuracy of ultrasonography-guided aspiration biopsy in diagnosing metastasis to lymph nodes was 96%; the results of this test prompted a change in management in 95% of the patients who had the procedure.
Conclusions: Endoscopic ultrasonography alone or with fine-needle aspiration biopsy adds useful diagnostic information in determining metastasis to posterior mediastinal or subcarinal lymph nodes in patients with non-small-cell lung cancer. These procedures are especially helpful in the preoperative evaluation of patients with suspicious contralateral mediastinal or “bulky” subcarinal nodes.