EGFR and cancer: Smoking is another important factor associated with the worsening of symptoms and poorer QOL on diagnosis and after treatment.16, 17 EGFR-TKIs have been demonstrated to have activity in EGFR-mutated patients with brain metastasis with a response rate of 70-80%.18 In addition, EGFR signaling is an important mediator of bone metastasis in many cancers.