Subtyping lung adenocarcinoma according to the novel 2011 IASLC/ATS/ERS classification: correlation with patient prognosis.

Lung adenocarcinoma, accounting for approximately 70% of non-small cell lung cancer, is becoming more frequently detected, and is a radiologically, histomorphologically, molecularly, and clinically heterogeneous tumor with a broad range of malignant behavior. Histologic subtyping is an important independent prognostic variable in lung adenocarcinoma. In the 2011 IASLC/ATS/ERS classification, the term bronchioloalveolar carcinoma is eliminated, adenocarcinoma in situ and minimally invasive adenocarcinoma are defined, and the term lepidic is resurrected. The impact of subtyping on patient survival according to the 2011 classification is independent of known prognostic factors, such as TNM stage. The role of clinical decision making for treating lung adenocarcinoma is predominantly based on subtyping similar to that of breast and prostate cancer.