Molecular analysis in cytological samples obtained by endobronchial or oesophageal ultrasound guided needle aspiration in non-small cell lung cancer.

INTRODUCTION: Cytological samples obtained by endobronchial ultrasound (EBUS) are capital for diagnosis, staging and molecular profile in non-small cell lung carcinoma (NSCLC). OBJECTIVE: To assess the success rate of complete, partial and individual of molecular analysis in samples obtained by EBUS-guided transbronchial needle aspiration (TBNA) and/or by oesophageal ultrasound-guided fine needle aspiration with an echobronchoscope (EUS-B-FNA) in patients with NSCLC. METHODS: Prospective study including 90 patients with non-squamous NSCLC, or non-smoking squamous. Cytological samples were classified into two groups. Group 1: PEN membrane slide and/or cell blocks for the determination of mutations of EGFR, KRAS, ERBB2 and BRAF. Group 2: silane coated slides or cell blocks for rearrangements of ALK, ROS1 and MET amplification. RESULTS: The success rate was 78.6% for 4 molecular alterations (EGFR, KRAS, ALK and ROS1), and 44% for 7 determinations. The individual success rate for EGFR was 97%, KRAS 96.3%, ALK 85%, ROS1 82.3%, ERBB2 71.4%, BRAF 67.7% and MET 81.1%. There were no significant differences (p=0.489) in the number of molecular analyses (1-3 vs. 4) in group 1, depending on the types of samples (cell block vs. PEN membrane slide vs. cell block and PEN membrane slide). CONCLUSIONS: In patients with NSCLC, the cytological material obtained by ultrasound-guided needle aspiration is sufficient for individual and partial molecular analysis in the vast majority of cases. Membrane slides such as cell blocks are valid samples for molecular analysis.

Identification of oestrogen, progesterone receptor and human epidermal growth factor receptor 2 expression in mediastinal metastases of breast cancer obtained by endobronchial ultrasound-guided transbronchial needle aspiration.

BACKGROUND: In breast cancer patients, the expression statuses of oestrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor 2 (HER2) are crucial in the choice of treatment. Receptor expression in metastatic lesions can differ from the primary tumour. The aim of our study was to analyse the utility of endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) to obtain samples allowing the identification of ER, PR and HER2 expression in patients with mediastinal metastases of breast cancer. PATIENTS AND METHODS: The clinical files of all patients with a final diagnosis of breast cancer mediastinal metastases diagnosed by EBUS-TBNA in our institution were retrospectively analysed. The ability of EBUS-TBNA to obtain samples that allowed hormone receptor and HER2 expression analysis was calculated. RESULTS: Twenty-four patients were included. ER, PR and HER2 assessments could be performed in 22, 20 and 22 patients, respectively. In 20 of the 24 patients it was possible to investigate all three types of receptor expression. In the remaining four cases, where ER, PR or HER2 expression tests could not be performed, it was due to a lack of tissue. In cases with adequate results for EBUS-TBNA and the primary tumour agreement was greater for ER (16/19) and HER2 (12/14) than PR (8/17). Based on receptor status, there was a change in the choice of treatment for five patients. CONCLUSION: In patients with breast cancer mediastinal metastases, ER, PR and HER2 expression can be assessed in samples obtained by EBUS-TBNA whenever a sufficient tissue sample is collected.

Representativeness of nodal sampling with endobronchial ultrasonography in non-small-cell lung cancer staging.

The objective of our study was to determine the procedure-related requirements of mediastinal node sampling with endobronchial ultrasonography with real-time transbronchial needle aspiration (EBUS-TBNA) that would provide negative predictive value (NPV) for the identification of stage III disease in non-small-cell lung cancer (NSCLC) high enough to consider the technique equivalent to cervical mediastinoscopy. Representative EBUS-TBNA was defined as a sampling procedure obtaining satisfactory samples from normal nodes in regions 4R, 4L and 7 or diagnosing malignancy in mediastinal nodes. NPV was estimated using the results of postsurgical staging in patients who underwent surgery as a reference. Two-hundred ninety-six patients staged with EBUS-TBNA were included. Representative samples from regions 4R, 4L and 7 showing nonmalignant cytology were obtained from 98 patients (33.1%) and EBUS-TBNA detected N2/N3 disease in 150 (50.7%). Accordingly, an EBUS-TBNA procedure accomplishing the representativeness criteria required for sampling was attained in 248 of the participating patients (83.8%). The NPV of the procedure in this setting was 93.6%, with false-negative results only found in 5 patients, four of them with nodal metastasis out of the reach of EBUS-TBNA (regions 5, 8 and 9). In conclusion, representative sampling of regions 4R, 4L and 7 is achieved in more than 80% of patients staged using EBUS-TBNA, and in the procedures that attain this requirement a NPV >90% for mediastinal malignancy is reached, a figure equivalent to cervical mediastinoscopy.

Endobronchial ultrasound-guided transbronchial needle aspiration for identifying EGFR mutations.

The presence of somatic mutations of the tyrosine kinase domain of the epidermal growth factor receptor (EGFR) gene in patients with advanced nonsmall cell lung cancer (NSCLC) correlates with a good response to tyrosine kinase inhibitors. The usefulness of endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) for the detection of EGFR mutations in cells recovered from malignant mediastinal nodes in patients with NSCLC was assessed. All patients with lung adenocarcinoma or unspecified NSCLC referred for staging with EBUS-TBNA were included. Nodes with a short-axis diameter of >5 mm were sampled, and genomic DNA from metastatic tumour cells was obtained for analysis of exons 19 and 21. The impact of sampling on management was assessed. EGFR gene analysis of the EBUS-TBNA sample was feasible in 26 (72.2%) out of the 36 patients with lymph node metastasis. Somatic mutations of the EGFR gene were detected in tissue obtained through EBUS-TBNA in two (10%) out of 20 patients with metastasic lung adenocarcinoma. Malignant tissue samples obtained by EBUS-TBNA from patients with nodal metastasis of NSCLC are suitable for the detection of EGFR mutations in most cases, and this technique demonstrates mutated neoplastic cells in a tenth of patients with adenocarcinoma.