Using endosonography to determine lung cancer metastases in the upper chest was found more sensitive in detecting cancer spread that surgical procedures, yet it did not improve survival in patients, a recent study revealed.
Researchers behind the study, “Five-Year Survival After Endosonography vs Mediastinoscopy for Mediastinal Nodal Staging of Lung Cancer,” which was published in the journal JAMA, suggested that the trial might have been too small to detect differences in survival after different diagnostic procedures.
But since endosonography is now recommended in clinical guidelines, it is unlikely that clinical trials further exploring this difference will be conducted.
The identification of lung cancer metastases in the mediastinum — the tissue between and in front of the lungs — is crucial for choosing the right treatment and being able to set a prognosis for a lung cancer patient.
Various procedures exist for the process, called mediastinal nodal staging by physicians. The ASTER study (Assessment of Surgical Staging vs Endosonographic Ultrassound in Lung Cancer, NCT00432640) compared a surgical procedure called mediastinoscopy to endosonography, a method combining endoscopy with ultrasound.
The trial found that endosonography was more sensitive in detecting metastases, and researchers at the Academic Medical Center in The Netherlands decided to explore if the improved procedure led to better treatment, and ultimately better survival.
The study included 241 patients with non-small cell lung cancer that was potentially possible to remove by surgery. Patients were randomized to either endosonographic (123 patients) or surgical staging (118 patients).
Researchers got access to survival data at five years for 237 out of the original 241 patients. Among patients examined with endosonography, 54 percent had chest metastases, while among those examined with the surgical procedure, 44 percent had metastases.
Surprisingly, survival at five years was 35 percent in both groups. The estimated median survival time was 31 months for patients examined with endosonography, and 33 months for those examined with mediastinoscopy.
Researchers argue that the results are not likely caused by missing data, as only information on four patients, amounting to less than 2 percent, was unavailable. Instead, the team believes that the study included too few participants to detect the relatively small differences the two approaches may have introduced.