Preoperative use of mediastinoscopy and transesophageal ultrasound-guided fine needle aspiration may improve accuracy of clinical staging for lung cancer, according to an article in the August 24/31 issue of the Journal of the American Medical Association.
Accurate preoperative staging is important in identifying patients who will benefit from surgical resection. Currently available staging techniques have limited accuracy in selecting lung cancer patients without regional lymph node metastases.

Transesophageal ultrasound-guided fine needle aspiration is a minimally invasive and safe technique than can target different lymph node stations and is complementary to mediastinoscopy. An ultrasound transducer that is incorporated on top of an endoscope enables the investigator to visualize and insert the aspiration needle into mediastinal lymph nodes under real-time ultrasound guidance.

The guided aspiration examination has a sensitivity of 88 percent and a specificity of 91 percent in analyzing mediastinal lymph nodes. To date it is not known how transesophageal ultrasound-guided fine-needle aspiration compares with mediastinoscopy, nor to what extent the combination of techniques improves preoperative staging.

Jouke T. Annema, MD, PhD, of Leiden University Medical Center, the Netherlands, and colleagues conducted a study to determine whether lung cancer staging by guided fine-needle aspiration in addition to mediastinoscopy improved preoperative staging compared with staging by mediastinoscopy alone.

During a three-year period (2000-2003), 107 patients with potentially resectable non-small cell lung cancer underwent preoperative staging by both techniques. Patients underwent thoracotomy with tumor resection if mediastinoscopy was negative. Surgical-pathological staging was compared with preoperative findings and the added benefit of the combined strategy was assessed.

The combination of nonsurgical techniques identified more patients with tumor invasion or lymph node metastases (36 percent) than either mediastinoscopy alone (20 percent) or ultrasound-guided fine-needle aspiration (28 percent) alone. This indicated that 16 percent of thoractomies could have been avoided by using the combination of techniques. However, 2 percent of fine-needle aspiration findings were false-positive.

The authors concluded, "Overall, mediastinoscopy and esophageal ultrasound-guided fine-needle aspiration (EUS-FNA) have inherent limitations and they should be viewed as complementary in the regional staging of non-small cell lung cancer. These preliminary findings suggest that EUS-FNA, a novel, minimally invasive staging procedure for lung cancer, may improve the preoperative staging due to the complementary reach of EUS-FNA in detecting mediastinal lymph node metastases and the ability to assess mediastinal tumor invasion. However, the occurrence of false-positive EUS-FNA findings in selected cases needs to be further investigated."