title: EGFRmutation in squamous cell carcinoma of the lung: does it carry the same connotation as in adenocarcinomas?
abstract: BACKGROUND
  EGFR tyrosine kinase inhibitors (TKIs) have greatly improved the outcomes ofEGFRmutation-positive adenocarcinomas of the lung. In contrast, the significance ofEGFRmutation in metastatic squamous cell carcinoma (SCC) of the lung has been debated.
  
  
  METHODS
  All patients with metastatic SCC who underwentEGFRmutation testing at our center from 2010 to 2015 were included for analysis.EGFRkinase domain mutations were tested using Taqman-based real-time polymerase chain reaction (PCR). Response assessment was done using Response Evaluation Criteria In Solid Tumors (RECIST) 1.1. Kaplan-Meier method was used for calculating progression-free survival (PFS) and overall survival (OS).
  
  
  RESULTS
  EGFRmutation was detected in 29 out of 639 patients with SCC. Furthermore, 19 out of the 29 patients received TKIs at some point during their treatment. TKI therapy led to a partial response in 5 out of 19 patients and stable disease in 4 out of 19 patients. The median PFS of patients treated with TKIs was 5.0 months. The median OS of the wholeEGFR-positive SCC cohort was 6.6 months. On univariate analysis, patients having received TKI therapy was the only factor associated with a significantly better OS of 13.48 months versus 2.58 months (P=0.000). On multivariate analysis, patients receiving TKI therapy, Eastern Cooperative Oncology Group-Performance Scale (ECOG-PS) score <2,EGFRexon 19 mutation and nonsmoking status were associated with significantly better OS.
  
  
  CONCLUSIONS
  EGFRmutation in SCC of the lung predicts a better outcome if the patient is given TKI, but it may be inferior to the outcomes seen inEGFR-positive adenocarcinomas treated with TKI.
authors.affiliation: Department of Medical Oncology, Tata Memorial Hospital.
authors.forename: Amit
authors.initials: A
authors.lastname: Joshi
authors.affiliation: Department of Medical Oncology, Tata Memorial Hospital.
authors.forename: Saurabh
authors.initials: S
authors.lastname: Zanwar
authors.affiliation: Department of Medical Oncology, Tata Memorial Hospital.
authors.forename: Vanita
authors.initials: V
authors.lastname: Noronha
authors.affiliation: Department of Medical Oncology, Tata Memorial Hospital.
authors.forename: Vijay M
authors.initials: VM
authors.lastname: Patil
authors.affiliation: Molecular Laboratory, Department of Medical Oncology.
authors.forename: Anuradha
authors.initials: A
authors.lastname: Chougule
authors.affiliation: Department of Pathology.
authors.forename: Rajiv
authors.initials: R
authors.lastname: Kumar
authors.affiliation: Department of Radiology, Tata Memorial Hospital, Mumbai, Maharashtra, India.
authors.forename: Amit
authors.initials: A
authors.lastname: Janu
authors.affiliation: Department of Radiology, Tata Memorial Hospital, Mumbai, Maharashtra, India.
authors.forename: Abhishek
authors.initials: A
authors.lastname: Mahajan
authors.affiliation: Department of Medical Oncology, Tata Memorial Hospital.
authors.forename: Akhil
authors.initials: A
authors.lastname: Kapoor
authors.affiliation: Department of Medical Oncology, Tata Memorial Hospital.
authors.forename: Kumar
authors.initials: K
authors.lastname: Prabhash
keywords: EGFR mutation; SCC lung; TKI efficacy; squamous cell carcinoma