ABSTRACT
BACKGROUND: To determine the frequency and predictive impact of ROS1 rearrangements on treatment outcomes in never-smoking patients with lung adenocarcinoma. PATIENTS AND METHODS: We concurrently analyzed ROS1 and ALK rearrangements and mutations in the epidermal growth factor receptor (EGFR), and KRAS in 208 never smokers with lung adenocarcinoma. ROS1 and ALK rearrangements were identified by fluorescent in situ hybridization. RESULTS: Of 208 tumors screened, 7 (3.4%) were ROS1 rearranged, and 15 (7.2%) were ALK-rearranged. CD74-ROS1 fusions were identified in two patients using reverse transcriptase-polymerase chain reaction. The frequency of ROS1 rearrangement was 5.7% (6 of 105) among EGFR/KRAS/ALK-negative patients. Patients with ROS1 rearrangement had a higher objective response rate (ORR; 60.0% versus 8.5%; P = 0.01) and a longer median progression-free survival (PFS; not reached versus 3.3 months; P = 0.008) to pemetrexed than those without ROS1/ALK rearrangement. The PFS to EGFR-tyrosine kinase inhibitors in patients harboring ROS1 rearrangement was shorter than those without ROS1/ALK rearrangement (2.5 versus 7.8 months; P = 0.01). CONCLUSIONS: The frequency of ROS1 rearrangements in clinically selected patients is higher than that reported for unselected patients, suggesting that ROS1 rearrangement is a druggable target in East-Asian never smokers with lung adenocarcinoma. Given the different treatment outcomes to conventional therapies and availability of ROS1 inhibitors, identification of ROS1 rearrangement can lead to successful treatment in ROS1-rearranged lung adenocarcinomas.
Subject(s)
Adenocarcinoma/genetics , Carcinoma, Non-Small-Cell Lung/genetics , Lung Neoplasms/genetics , Protein-Tyrosine Kinases/genetics , Proto-Oncogene Proteins/genetics , Recombinant Fusion Proteins/genetics , Adenocarcinoma/drug therapy , Adenocarcinoma of Lung , Adult , Aged , Anaplastic Lymphoma Kinase , Antigens, Differentiation, B-Lymphocyte/genetics , Carcinoma, Non-Small-Cell Lung/drug therapy , Cell Line, Tumor , Cell Survival/drug effects , Crizotinib , Disease-Free Survival , ErbB Receptors/genetics , Female , Gefitinib , Gene Frequency/genetics , Gene Rearrangement/genetics , Glutamates/pharmacology , Glutamates/therapeutic use , Guanine/analogs & derivatives , Guanine/pharmacology , Guanine/therapeutic use , Histocompatibility Antigens Class II/genetics , Humans , Lung Neoplasms/drug therapy , Male , Middle Aged , Mutation/genetics , Pemetrexed , Protein-Tyrosine Kinases/metabolism , Proto-Oncogene Proteins/metabolism , Proto-Oncogene Proteins p21(ras) , Pyrazoles/pharmacology , Pyridines/pharmacology , Pyrimidines/pharmacology , Quinazolines/pharmacology , Receptor Protein-Tyrosine Kinases/genetics , Receptor Protein-Tyrosine Kinases/metabolism , Recombinant Fusion Proteins/metabolism , Reverse Transcriptase Polymerase Chain Reaction , Smoking , Treatment Outcome , ras Proteins/geneticsABSTRACT
METHODS: Fluorescent in situ hybridisation analyses of PTEN, PIK3CA, EGFR and CEN7 were performed on tumour specimens from patients treated on the expanded access gefitinib trial. Progression-free survival (PFS) and overall survival (OS) were correlated with outcomes in all patients and EGFR wild-type patients. RESULTS: Progression-free survival (hazard ratio=2.54, P<0.001) and OS (hazard ratio=4.04, P<0.001) were significantly shorter in patients whose tumours had all of the following molecular patterns: CEN7 <4 copies per cell, PTEN loss (<2 copies in at least 20% of cells), and PIK3CA gain (>2 copies in at least 40% of cells) both in all and EGFR wild-type only patients. CONCLUSION: The combination of low CEN7 copy number, PTEN loss, and PI3KCA gain may be useful for identifying NSCLC patients unlikely to benefit from treatment with EGFR (TKIs), specifically in wild-type EGFR cases.