Subtype Classification of Lung Adenocarcinoma Predicts Benefit From Adjuvant Chemotherapy in Patients Undergoing Complete Resection

The most recent WHO classification for lung adenocarcinoma is based on the predominant histologic subtype in the resected tumor. Several studies have validated the use of this classification system for  prognostic purposes, but predicting response to adjuvant chemotherapy has not yet been tested. The goal of this study was to determine whether this classification can be used to predict benefit from adjuvant chemotherapy in patients who have undergone complete surgical resection. The Lung Adjuvant Cisplatin Evalutaion Biomarker (LACE-Bio) collabortive group formed a large cohort of patients from four adjuvant chemotherapy clinical trials (n=552 for this study).  Two groups were compared: acinar/papillary (n=247) and micropapillary/solid (n=305). Patients in the micropapillary/solid subgroup had a significant benefit from adjuvant chemotherapy in terms of disease-free survival, whereas patients in the acinar/papillary subgroup did not.