Tissue Is the Issue: Is Endoscopic Ultrasonography with or without Fine-Needle Aspiration Biopsy in the Staging of Non-Small-Cell Lung Cancer an Advance?

Non-small-cell lung cancer is the leading cause of death from malignancy in the United States [1]. The TNM (T = primary tumor, N = regional lymph nodes, M = distant metastasis) staging system for this type of cancer subdivides patients into anatomic groups. This system is central to determining treatment options and prognosis and to comparing survival among therapeutic trials [1]. In the absence of distant metastasis, mediastinal lymph node metastasis in non-small-cell lung cancer is a critical issue. Almost half of patients with this type of cancer present with metastasis to the mediastinal lymph nodes, a characteristic that is the major obstacle to cure. Ipsilateral mediastinal and subcarinal lymph nodes are designated as N2 nodes, and contralateral mediastinal lymph nodes are considered N3 nodes. Patients with T1 (<3 cm) or T2 (>3 cm) non-small-cell lung cancer and N2 metastasis (stage IIIA) are potential candidates for surgery. Surgical resection is generally not curative, however, and most patients with N2 disease receive multimodality treatment (for example, surgery, neoadjuvant chemotherapy, adjuvant radiation therapy, and chemotherapy) [1]. Optimal treatment for N3 disease (stage IIIB) is combination chemotherapy and radiation therapy [1]. The 5-year survival rate is approximately 30% in patients with stage N2 disease documented at surgical resection and approximately 5% in patients with N3 disease determined on radiography [2]. Thus, distinguishing between N2 and N3 disease in non-small-cell lung cancer has major implications for both treatment and prognosis.

To evaluate the mediastinal lymph nodes, computed tomography of the thorax with intravenous contrast scanning should be done in patients suspected of having lung …