New non-invasive test for staging avoids unneeded surgery

[Leslie221]

Combination technology could reduce unneeded surgery[/b

]Source: (cancerfacts.com)

Saturday, August 27, 2005

LEIDEN, Netherlands – Aug. 27, 2005 – A test that combines two technologies may help improve the accuracy of determining the stage of lung cancer, according to a new study.

Led by Dr. Jouke T. Annema, of Leiden University Medical Center, Netherlands, the researchers used a form of ultrasound together with a surgical device inserted into the chest through a small incision to spot cancer that has spread from the lungs to nearby lymph nodes.

The minimally invasive technique is called esophageal ultra-sound guided fine needle aspiration or EUS-FNA. Used to more accurately assess the stage of lung cancer, the technique uses an ultrasound imaging probe inserted into the throat to produce an ultrasound image of the chest. Then through a small incision above the breast bone, the surgeon inserts a surgical device, called a mediastinoscope, which is a flexible tube that can be fitted with a biopsy needle. Using the ultrasound image to guide the needle, the surgeon is able to take tiny samples of lung tissue and nearby lymph nodes for examination under a microscope.

"The results can be explained by the fact that EUS-FNA and mediastinoscopy have a complementary reach in assessing regional lymph node stations and in the ability of EUS-FNA to detect mediastinal tumor invasion," the authors wrote. "Our findings are directly applicable to clinical practice."

Accurate preoperative staging is important in identifying those patients who will benefit from surgery to remove cancerous tissue. Currently available staging techniques have limited accuracy in selecting those lung cancer patients without regional lymph node metastases.

Up to 40 percent of chest surgeries performed for non-small cell lung cancer (NSCLC) are reported to be unnecessary, predominantly due to inaccurate preoperative detection of lymph node involvement, according to the study authors. By combining ultrasound imaging with mediastinoscopy, they hope to improve on that.

Between 2000 and 2003, the researchers staged 107 patients from 6 hospitals in the Netherlands with non-small cell lung cancer that was potentially treatable with surgery using both EUS-FNA and mediastinoscopy. Patients then underwent open chest surgery to remove lung tumors if mediastinoscopy showed the cancer had not spread to the lymph nodes.

The researchers found that the combination of EUS-FNA and mediastinoscopy identified more patients with tumor invasion or lymph node metastases (36 percent) compared with either mediastinoscopy alone (20 percent) or EUS-FNA (28 percent) alone. This indicated that 16 percent of thoractomies could have been avoided by using EUS-FNA in addition to mediastinoscopy.

Using EUS-FNA the researchers were able to detect 88 percent of tumors and correctly identified cancerous tumors 91 percent of the time in analyzing mediastinal lymph nodes. However, 2 percent of the EUS-FNA findings were false-positive, meaning they incorrectly identified tumors as cancer when they were not.

Currently, surgeons use only mediastinoscopy to perform such staging, and the researchers note that more research needs to be done to compare the two to determine to what extent the combination of EUS-FNA and mediastinoscopy improves preoperative staging.

"Overall, mediastinoscopy and EUS-FNA have inherent limitations and they should be viewed as complementary in the regional staging of NSCLC. These preliminary findings suggest that EUS-FNA, a novel, minimally invasive staging procedure for lung cancer, may improve the preoperative staging," the researchers conclude.