mutation in squamous cell carcinoma of the lung: does it carry the same connotation as in adenocarcinomas?

BACKGROUND

EGFR tyrosine kinase inhibitors (TKIs) have greatly improved the outcomes of mutation-positive adenocarcinomas of the lung. In contrast, the significance of mutation in metastatic squamous cell carcinoma (SCC) of the lung has been debated.

METHODS

All patients with metastatic SCC who underwent mutation testing at our center from 2010 to 2015 were included for analysis. kinase 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

mutation 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 whole -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 (=0.000). On multivariate analysis, patients receiving TKI therapy, Eastern Cooperative Oncology Group-Performance Scale (ECOG-PS) score <2, exon 19 mutation and nonsmoking status were associated with significantly better OS.

CONCLUSION

mutation in SCC of the lung predicts a better outcome if the patient is given TKI, but it may be inferior to the outcomes seen in -positive adenocarcinomas treated with TKI.