Noninvasive clinical staging modalities for lung cancer

Abstract

Clinical staging of lung cancer helps to determine the extent of disease and stratify patients into similar therapeutic and prognostic categories. A primary goal of clinical staging is to separate patients with potentially resectable disease from those that are unresectable. Initial assessment of the patient by history and physical examination combined with laboratory values can suggest metastatic spread of the disease. When abnormal, these clinical factors may have value in terms of predicting prognosis, but their use in early stage lung cancer is limited because of the low prevalence of symptoms, physical exam findings, and laboratory abnormalities in this group. For clinical staging, patients almost always undergo a postero-anterior and lateral chest radiograph and a computed tomography (CT) scan of the chest and upper abdomen to include the liver and adrenal glands. Although CT scanning provides exquisite anatomic information, it is less than optimal for determining lymph node status. Over the last several years, CT scanning combined with positron-emission tomography (PET) using fluorodeoxyglucose (FDG) has significantly improved the accuracy of clinical staging. The use of FDG-PET continues to be defined in the non-invasive evaluation of the primary tumor, nodal involvement, and metastatic disease. Despite the recent advancements in radiologic assessment of lung cancer, invasive sampling is still often performed for pathologic confirmation.