Lung Cancer Staging and Prognosis

The seventh edition of the non-small cell lung cancer (NSCLC) TNM staging system was developed by the International Association for the Staging of Lung Cancer (IASLC) Lung Cancer Staging Project by a coordinated international effort to develop data-derived TNM classifications with significant survival differences. Based on these TNM groupings, current 5-year survival estimates in NSLCC range from 73 % in stage IA disease to 13 % in stage IV disease. TNM stage remains the most important prognostic factor in predicting recurrence rates and survival times, followed by tumor histologic grade, and patient sex, age, and performance status. Molecular prognostication in lung cancer is an exploding area of research where interest has moved beyond TNM stage and into individualized genetic tumor analysis with immunohistochemistry, microarray, and mutation profiles. However, despite intense research efforts and countless publications, no molecular prognostic marker has been adopted into clinical use since most fail in subsequent cross-validation with few exceptions. The recent interest in immunotherapy for NSCLC has identified new biomarkers with early evidence that suggests that PD-L1 is a predictive marker of a good response to new immunotherapy drugs but a poor prognostic indicator of overall survival. Future prognostication of outcomes in NSCLC will likely be based on a combination of TNM stage and molecular tumor profiling and yield more precise, individualized survival estimates and treatment algorithms.