FISH FISH was performed on 4.5 μm TMA sections or whole FFPE archival tissue samples using the ZytoLight ® SPEC EGFR/CEN 7 Dual color probe (ZytoVision, Bremerhaven, Germany/Menarini Diagnostics, Greece), the LSI D7S486/CEP7 Dual Color Probe, (Abbott Molecular, IL, USA) and the specific HGFR/MET gene at region 7q31, Poseidon™ Repeat Free™ MET/SE7 probe (Kreatech Diagnostics, NL) as previously described [26]. FISH assays,

were captured by a computer-controlled digital camera and processed by commercially available software (XCyto-Gen, Alphelys, France). Sequential, digital images were captured GDC-0449 manufacturer by a stack motor for each fluorescence filter and the resulting images were reconstructed with blue, green and orange or red

pseudo-colors. Sixty non-overlapping intact nuclei from the invasive part of the tumor were evaluated for each case according to morphological criteria using TGF-beta inhibitor review DAPI staining. FISH patterns for the EGFR gene were defined as previously described [27]. MET gene status was classified according to Cappuzzo et al. [28] in two strata as follows: 1) FISH positive if mean MET gene ratio was ≥5 gene copies per cell, 2) FISH negative if mean MET gene ratio was <5 gene copies per cell. The status of the D7S486 locus was evaluated as follows: amplification if the ratio D7S486/CEP7 was ≥2, and deletion if ratio was <0.7. Statistical analysis Endpoints included PFS (progression free survival) and overall survival (OS) in association with the candidate biomarkers. PFS was computed as the time from initiation of treatment until recurrence of tumor or death from any cause. Survival was defined as the time from first day of treatment until

death from any cause. Disease control rate (DCR), was defined very as the sum of patients who selleck chemicals llc achieved complete (CR) or partial response (PR) and those who had stability of their disease (SD). Fisher’s exact test was used for comparing groups of categorical data, while for continuous data the Mann–Whitney test was used. P values of at least 0.05 were considered statistically significant. Kaplan-Meier curves and log-rank test were used for comparing time to event distributions. Univariate Cox regression analyses were performed to estimate hazard ratios (HR). All analyses were performed using SPSS version 15.0, in the HeCOG data office. Results A total of 72 patients received treatment. However, 8 cases were excluded due to incomplete medical records and a further 5 due to insufficient tumor in their biopsies. Baseline characteristics of the 59 eligible cases for the translational study (28 gefitinib, 31 erlotinib) are listed in Table  1. Adenocarcinoma was identified in the majority of cases (68%). Approximately two thirds of patients were males, and 32% had never smoked. There were no significant differences in selected patients and tumor characteristics between the two treatment groups.