The clinical staging of non-small cell lung cancer (NSCLC) is of paramount importance. It determines prognosis and therapy, and inaccurate staging may result in inappropriate treatment. In particular, clinical staging that misses mediastinal metastases may result in the patient undergoing a futile thoracotomy. Conversely, accurately detecting mediastinal metastases preoperatively would allow consideration of concurrent chemoradiotherapy or neoadjuvant treatment.

Although sensitivity and specificity data of CT scanning, positron emission tomography (PET) and mediastinoscopy for the detection of mediastinal metastases exist, the impact on patient outcomes when combined with other standard staging techniques such as mediastinoscopy is limited. The MRC LU22 trial,1 which compared surgery alone with neoadjuvant chemotherapy followed by surgery, collected prospective data on clinical and pathological staging …