ABSTRACT
INTRODUCTION Lung cancer is a heterogeneous tumor entity. While in small cell lung cancer (SCLC) pathological classifi cation and treatment were modifi ed only marginally over the last decades, non-small cell lung cancer (NSCLC) is increasingly classifi ed and treated by use of diverse molecular biomarkers in addition to traditional histologic subtyping. These biomarkers may have diagnostic, predictive, or prognostic relevance. At present no serum marker is available as a diagnostic or follow-up tool; however, this may become an important future topic-potentially involving circulating tumor cells, circulating DNA, serum microvesicles, or other serum proteomic marker, alone or in combination. Of note, how such a biomarker would be able to add to the promising results demonstrated by computer tomography screening in a high-risk smoker population will have to be determined.1
