EGFR and non-small cell lung carcinoma: In NSCLC patients with PR, the presence or absence of EGFR mutation, the number and sites of recurrence (intra/extra thoracic), and the presence/absence of CNS metastasis have been well established as prognostic factors [15, 16], although opinions conflict regarding the influence of bone metastases at recurrence on the prognosis [8, 9].