Improvements in clinical management of lung cancer have been modest over the last 20 years and with almost 1.6 million deaths worldwide (19% of the total) it still has the highest mortality rate among cancers. So far no valid biomarker has proven to be useful in lung cancer clinical practice and in reducing mortality. Technical limitations, as well as genetic and biological tumor heterogeneity have likely limited the successful identification of tumor-specific markers. An interesting landmark to identify novel and more reliable biomarkers is searching for candidates by looking not only at the tumor itself but also at the interplay between the tumor and the host with the aim to identify changes related to the biological reactivity of the host to a developing cancer.
