Biological markers are cellular, structural and biochemical components that can define cellular as well as molecular changes in both normal and neoplastic cells. There are two types of biological markers: 1) intermediate markers that evaluate cellular and molecular alterations before malignancy occurs; and 2) diagnostic markers, present in association with malignancy. The identification and validation of biological markers for clinical use are performed in stages: <FONT FACE=Symbol>¨</FONT> initial identification in cell cultures of the tumor; <FONT FACE=Symbol>¨</FONT> testing of the marker in tissues obtained in biopsies of patients with an established diagnosis of the tumor; <FONT FACE=Symbol>¨</FONT> testing of biopsies of normal tissues and tissues with an inflammatory process; <FONT FACE=Symbol>¨</FONT> sputum, blood or urine tests for validation as a non-invasive test that can be used in high-risk populations. Sorologic and histopathologic biological markers are cellular, structural and biochemical components found in both normal and neoplastic cells that can be quantitatively assessed by biochemical, immunological and molecular methods in the body fluids or tissues, respectively, and may be associated with malignancies and, possibly, with the neoplastic organ. Biological markers are studied in diverse primary neoplasms. However, few of them proved to be clinically valuable. The role of biological markers in lung cancer patients remains unclear because only a small number of markers has been properly assessed. The aim of this paper is to understand the role of sorologic and histologic biological markers in the prognosis and survival of lung cancer patients based on our previous works. Furthermore, we present a future perspective of the early detection of lung cancer on the basis of the role of intermediate biological markers.
Biologic markers; Lung cancer; Prognosis; Survival. Morphometric method
