The combination of endobronchial and transesophageal endoscopic ultrasound-guided fine-needle aspiration appears to be superior to the standard transbronchial approach for mediastinal staging of suspected lung cancer, according to an article in the February 6 issue of the Journal of the American Medical Association.

"Both scopes together found more malignant lymph nodes than did the use of a single endoscope," said lead investigator, Michael Wallace, MD, MPH, Professor of Medicine at Mayo Clinic, Jacksonville, Fla. "Doing both procedures at once takes little time, requires only a mild sedative, and patients go home the same day."

The combination technique was pioneered by Wallace, a gastroenterologist, and study co-author Jorge Pascual, MD, a pulmonologist. Because the researchers saw how effective the new method is, the two tests came into routine use at Mayo Clinic Jacksonville to stage patients and designed the comparison study to evaluate different staging techniques.

Traditional staging begins with computed tomographic scanning of the lungs to find enlarged lymph nodes. Positron emission tomography can be used to find nodes with higher metabolism. Under both noninvasive scenarios, the American College of Chest Physicians recommends that findings be confirmed by biopsy.

Historically, biopsy has been done surgically via mediastinoscopy. Studies summarized by the American College of Chest Physicians have shown it is approximately 78 percent sensitive. The most common alternative to mediastinoscopy is transbronchial needle aspiration (TBNA). "You can't directly see the lymph nodes, which significantly limits accuracy of TBNA," Wallace said.

In the mid-1990s, endoscopic ultrasound (EUS) began to be used to stage lung cancer. While the procedure is extremely safe and accurate for lymph nodes in the back of the chest, the transesophageal approach cannot evaluate or biopsy lymph nodes in the front of the chest.

Four years ago, a new type of staging probe was developed: The endobronchial ultrasound probe (EBUS) can view the front and sides of the lungs. Based on the complementary nature of the two procedures, Mayo Clinic researchers began testing in 2005 to see whether patients would benefit from a comprehensive view of the lymph nodes surrounding their lungs.

To find out which of the scoping methods was most beneficial, 138 patients with lung cancer agreed to be tested with the three minimally invasive approaches: transbronchial, esophageal, and endobronchial. Procedures were all performed in one session in which a patient was lightly sedated. The pulmonologists who performed transbronchial and endobronchial needle aspiration were blinded to the results found afterward by gastroenterologists who performed the transesophageal testing and sampling.

After all procedures were complete, the results were evaluated by a surgeon, and surgery was performed only if there was no evidence of cancer spread.

In all, 42 malignant lymph nodes were found. The researchers then looked at the results of tests both individually and in combination. The combination of endobronchial and transesophageal approaches detected 93 percent of 42 malignant lymph nodes. The three remaining malignant nodes were found during surgery.

Wallace said "One was next to the aorta, so it was unsafe to biopsy, and the other two were very small cancers missed by the needle sampling."

Estimated sensitivities for the other procedures were 69 percent for the transesophageal approach, 69 percent for endobronchial approach, 36 percent for transbronchial approach, 79 percent for transesophageal and transbronchial, and 76 percent for endobronchial and transbronchial needle aspiration.

Wallace noted that use of combination endobronchial and transesophageal approaches requires "good integration between all of the different specialties involved in the care of lung cancer patients."