Early stage non-small-cell lung cancer: challenges in staging and adjuvant treatment: evidence-based staging.

Staging of non-small-cell lung cancer is a multidisciplinary process involving imaging, endoscopic and surgical techniques. Accuracy is vital in order to avoid false-positive interpretations leading to a false stage III or IV diagnosis in early stage patients, or false-negative findings leading to a false early stage diagnosis in patients with mediastinal lymph node disease. CT scan offers great anatomical detail of tumour spread, but radiological imaging lacks information on the biological nature of the lesions. The latter is brought in by 2-[fluorine-18] fluoro-2-deoxy-D-glucose-positron emission tomography (FDG-PET) scan as a metabolic imaging tool, which, however, has clearly lower spatial resolution. Therefore, contemporary staging relies on the combination of both, preferably in a fusion PET-CT scan. Absence of suspected lymph node metastasis on both CT and PET has a high negative predictive value, and these patients may in general proceed to surgery. In most others, tissue confirmation of the locoregional lymph node status is needed. The historical standard of mediastinoscopy is nowadays complemented by endoscopic techniques by the bronchial or esophageal approach. Each of these techniques remains important in modern staging algorithms. A practical scheme for rational staging in clinical practice is discussed.