Figure 1.

Circulating tumor cells (CTC) detection in brain metastasis non-small cell lung cancer (NSCLC) patients: (A) NSCLC patients with an oligo-brain disease are less frequently identified as CTC-positive compared to patients with multiple metastatic sites, including brain. (B) NSCLC patients that were treated by brain metastasis resection harbor CTCs significantly less frequently compared to brain metastasis patients treated by radiation or chemotherapy. (C) Representative pictures of EGFR-positive and EGFR-negative CTCs detected in an NSCLC patient. −: no EGFR expression; +: weak; ++: intermediate; +++: strong EGFR expression. OP: operation.