They had no significant difference in age, sex and smoking status between patients with or without EGFR mutation. In the EGFR wild type patients 50 conducted fusion gene detection.

Of these, 14 had ALK fusion (28%), 2 had ROS1 fusion (4%), and 3 had RET fusion (6%). PCR positive samples were all verified by DNA sequencing. The ALK fusions were: eight E(EML4) exon 13 with A(ALK) exon 20 fusions, four E20 with A20 fusions, one E18 with A20 fusion, and one E6 with A20 fusion. The ROS1 fusions were ROS1 exon 34 with TPM3 exon 8. The three RET fusions were all RET exon VE-822 concentration 12 with KIF5B exon n15. The patients who harbored fusion gene mutation were listed in Table 2. In the EML4-ALK patients, 11 were under 60 and 8 were none or light smokers. The TPM3-ROS1 and two KIF5B-RET patients were under 60 years old and none-smokers, and one KIF5B-RET patient was a heavy smoker (30 pack-years)

and under 60. There was no significant difference between the patients with and without any one of the fusion genes in sex, and smoking status (p > 0.05), but the patients with fusion gene mutations were younger than those without mutations (median age, 51 vs 61, p = 0.032). Thirty-five of the 50 patients received first-line chemotherapy in this hospital, including 29 carboplatin or cisplatin contained therapies, 2 single drug therapies and 4 TKI targeting EGFR therapies. In these patients, twenty-four did not carry any mutation of three fusion genes, eight were ALK fusion positive and three were RET fusion positive (Table 3). In FK506 the last follow-up, three patients did not get disease progression. ORR was 4.2% and 9.1% in patients without and with fusion gene mutation, respectively (p > 0.05); DCR was 50% and 72.7%, respectively (p > 0.05). The median PFS of the EML4-ALK positive patients was 4.2 (95% confidence interals, 1.890-6.510) months vs 2.8 (95% CI, 1.658-3.942) months (p = 0.706) in the EML4-ALK negative patients and in either one

of three genes positive patients it was 4.0 (95% CI, 2.605-5.395) months vs 2.7 (95% CI, 1.551-3.849) months Thymidylate synthase (p = 0.371) in the none-positive patients (Figure 2). Although there was no significant difference between the two cohorts, the results showed a trend that patients with fusion genes had a better chemotherapy response than those without any one of fusion genes in chemotherapy. Cell block (CB) is a method to concentrate and preserve cells in fluid samples for long use. Compared with effusion smears, CB contains more cells to be identified and helps pathologists in decision making. It has been used routinely in pathological classification and also in gene detection. In certain cases it has an advantage to other conventional pathological methods [24]. In advanced-stage patients who cannot have their tissues dissected, CB samples could be an alternative selection.