This study was aimed to evaluate the utility of a panel of antibodies, consisting of thyroid transcription factor-1 (TTF-1), p63, and cytokeratins (CK) 5/6 for distinguishing between small cell lung carcinoma (SCLC) and nonsmall cell lung carcinoma, as well as for identifying glandular or squamous differentiation in small tissues obtained by bronchoscopy. Bronchoscopic biopsies of 77 lung carcinoma cases with easily recognizable morphologic features were included in this study. All the cases were immunohistochemically stained for p63, CK5/6 [indicators of squamous cell carcinoma (SCC)] and TTF-1 [indicator of SCLC and adenocarcinoma (AC)]. Although, 28 SCLC displayed TTF-1 positive, p63 negative immunoprofile, most of the SCC (32/39) had the opposite immunoprofile. All of the 10 ACs were negative for p63 and most of them (8/10) were negative for CK5/6. p63 and CK 5/6 seem to be useful for differentiating AC and SCLC from SCC with 100% specificity and 82% sensitivity, 89% specificity and 79% sensitivity, respectively. It seems that to achieve histologic typing of lung cancer as accurate as possible, TTF-1 in combination with p63 and CK 5/6 might be useful components of immunohistochemical analysis of poorly differentiated lung carcinomas in biopsy tissues.

No abstract

No abstract

Epidermal growth factor receptor (EGFR) mutations are potential markers driving carcinogenesis, and may alter the response to EGFR tyrosine kinase inhibitors in patients with non-small cell lung cancer (NSCLC). The frequency of EGFR mutations in patients with NSCLC differs according to sex, smoking habits and regional-based ethnicity differences. The aim of the present study was to determine the frequency of EGFR mutations in Turkish patients with NSCLC to highlight the importance of regional differences, and their associations with patient characteristics. Genomic DNA was extracted from formalin-fixed and paraffin-embedded tumor tissue sections of 409 NSCLC patients. The most common EGFR mutations in exons 18, 19, 20 and 21 were detected using BioFilmChip-based microarray assay. The overall EGFR mutation frequency was 16.6%, and the highest mutation frequencies were observed in exon 19 (6.4%) and exon 21 (7.3%). There was a higher frequency of EGFR mutations in females compared with males and in never-smokers compared with smokers (both P≤0.05). These results were similar to other European population-based studies, but not consistent Middle-Eastern based studies. The present study may contribute to understanding the gradient frequency of EGFR mutation across different ethnicities, and in designing genome wide-based collaborations that may reveal novel decision making and susceptibility mutations in EGFR in patients with NSCLC.