ROS1 and non-small cell lung carcinoma: The ROS1 fusion-positive NSCLC patients who received pemetrexed-based chemotherapy also had a relatively better ORR or DCR than those treated with non-pemetrexed-based chemotherapy; however, it did not have the statistically difference (ORR, 23.8% vs. 16.0%, P = 0.770; DCR, 57.1% vs. 36.0%, P = 0.152).